Sepsis-induced myocardial dysfunction (septic cardiomyopathy) · ICU Topics

Cinematic ICU scene of a septic patient with an echocardiogram showing a globally hypokinetic left ventricle with reduced ejection fraction, a noradrenaline and dobutamine infusion running, a rising troponin and lactate on the monitor, clinical-blue lighting, medical educational, no faces, no text — FigureThe sepsis-induced cardiomyopathy — the reversible biventricular dysfunction of the severe sepsis. The echo shows the reduced ejection fraction and the fixed stroke volume; the cardiac biomarkers are raised. The management is the treatment of the sepsis, with the cautious fluid, the vasopressor, and the inotrope; the function recovers over the 7 to 10 days.

Diagnosis and management of sepsis-induced cardiomyopathy

Recognise — septic shock with cardiac dysfunction (new LV dysfunction, elevated troponin, BNP)
Echocardiography — assess: LV systolic function (EF), LV dilatation, RV function, diastolic function, cardiac output, global longitudinal strain. Compare to baseline (if available)
Distinguish from cardiogenic shock — SICM: WARM shock (vasoplegic), high lactate (sepsis), source of infection, REVERSIBLE. Cardiogenic: COLD shock, elevated filling pressures, ischaemic cause
Treat sepsis — antibiotics within 1h, source control, fluid resuscitation (30 mL/kg crystalloid — but titrate to fluid responsiveness, avoid overload)
Vasopressors — noradrenaline FIRST-LINE (alpha vasoconstriction + modest beta). Target MAP ≥65. Add vasopressin if escalating noradrenaline requirement
Inotropes if low cardiac output — dobutamine (beta-1, increases contractility) or milrinone (PDE inhibitor, reduces afterload, pulmonary vasodilator). Use if: low cardiac output despite adequate volume + vasopressor, ongoing hypoperfusion (lactate, oliguria, mottled skin). Levosimendan NOT routinely recommended (LeoPARDS — no outcome benefit)
Monitor — echocardiography (serial — assess recovery), troponin/BNP trend, lactate clearance, urine output, clinical perfusion
Expect recovery — SICM typically REVERSES within 7-10 days (if sepsis controlled). Persistent dysfunction: consider alternative diagnosis (ischaemia, myocarditis, takotsubo, pre-existing cardiomyopathy)

Exam practice

SAQ — Septic cardiomyopathy with EF 25 percent and ongoing hypoperfusion

10 minutes · 10 marks

A 64-year-old man is admitted to ICU with septic shock from a perforated sigmoid diverticulum. He has received 30 mL/kg crystalloid and is on noradrenaline 0.35 mcg/kg/min (MAP 62, target 65). BP 92/56, HR 128 sinus, SpO2 94% on FiO2 0.5, temp 38.8°C, lactate 4.2 mmol/L, urine output 15 mL/hr, cool mottled peripheries. A passive leg raise produces no rise in cardiac output. Bedside echocardiography shows LV ejection fraction 25%, global hypokinesis with LV dilatation, TAPSE 14 mm, E/e' 16, IVC 2.4 cm with <10% collapsibility. High-sensitivity troponin T 480 ng/L, NT-proBNP 6800. ECG shows sinus tachycardia with no ST changes.

[1]

SAQ — Sepsis-induced cardiomyopathy versus pre-existing cardiomyopathy

10 minutes · 10 marks

A 72-year-old man is admitted to ICU with community-acquired pneumonia and septic shock (noradrenaline 0.4 mcg/kg/min, MAP 60, lactate 5.1 mmol/L, WCC 28). Bedside echocardiography shows LVEF 28% with global hypokinesis and a dilated LV (LVEDD 6.2 cm), E/e' 15, TAPSE 16 mm, no regional wall motion abnormality. Troponin T 320 ng/L, NT-proBNP 4200. He is unsure of his cardiac history; his wife recalls he was told his heart was 'a bit weak' three years ago but no records are available. You are asked whether this is sepsis-induced cardiomyopathy or pre-existing disease.

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Clinical pearls

High-yield septic cardiomyopathy points for CICM/FFICM exam

SICM is REVERSIBLE. Unlike ischaemic cardiomyopathy (permanent damage), SICM typically RECOVERS within 7-10 days (if sepsis treated successfully). EF returns to baseline in 60-80% of survivors. This REVERSIBILITY is the hallmark — distinguishes from permanent cardiomyopathy.[1]
Circulating myocardial depressant substances are the key mechanism. Sepsis → inflammatory cytokines (TNF-α, IL-1β, IL-6) + nitric oxide (NO) → DIRECTLY DEPRESS myocardial contractility. Evidence: serum from septic patients depresses isolated myocytes in vitro (Parrillo 1985, Kumar 1996). The depression is MEDIATED (not structural — no necrosis). Explains reversibility.[3][7]
Troponin is elevated in SICM (but it's NOT a heart attack). SICM causes myocardial injury (cytokine-mediated, microvascular dysfunction, mitochondrial dysfunction) → troponin leak. This is TYPE 2 MI (supply-demand) or direct cytokine injury — NOT type 1 (atherosclerotic plaque rupture). Don't automatically PCI an elevated troponin in sepsis (assess clinical context).[4][12]
LV dilatation is characteristic. Unlike ischaemic cardiomyopathy (which may have regional wall motion abnormalities), SICM causes GLOBAL hypokinesis + LV DILATATION (increased end-diastolic volume — the heart dilates to maintain stroke volume via Starling mechanism). This is adaptive (dilatation compensates for reduced contractility).[5]
RV dysfunction is also common (and often missed). SICM affects BOTH ventricles. RV dysfunction: reduced TAPSE, RV dilatation, tricuspid regurgitation. Contributes to: hypoxaemia (V/Q mismatch), shock (low output from RV failure). May need: pulmonary vasodilators (inhaled NO), volume management (avoid RV overload), inotropes (milrinone — pulmonary vasodilator + inotrope).[4][17]
Diastolic dysfunction often coexists with systolic. SICM causes impaired relaxation (diastolic dysfunction) as well as reduced contractility (systolic). Elevated filling pressures, reduced compliance. Contributes to pulmonary oedema (despite 'preserved' EF in some). Assess with echocardiography (E/A ratio, E/e' ratio, left atrial size).[2]
Cardiac output in septic shock — 'warm' vs 'cold'. CLASSIC septic shock: HIGH cardiac output (vasodilation → low SVR → compensatory high CO). WITH SICM: cardiac output may be NORMAL or LOW (myocardial depression limits compensatory increase). If LOW output in septic shock → SICM → add inotrope (dobutamine).[6]
Noradrenaline is first-line vasopressor (even with SICM). Noradrenaline: alpha-1 vasoconstriction (restores BP) + modest beta-1 (some contractility). PREFERRED for septic shock (with or without SICM). Dopamine: associated with MORE arrhythmias (SOAP II) — avoid. Vasopressin: add if noradrenaline inadequate.[9]
When to add inotrope in septic shock. Indications: (1) Low cardiac output despite adequate volume + vasopressor (hypoperfusion persists — lactate, oliguria, mottled skin). (2) Echocardiography shows reduced EF + LV dysfunction. (3) SICM confirmed. Drug: DOBUTAMINE (beta-1 — increases contractility, some beta-2 vasodilation) OR MILRINONE (PDE inhibitor — increases contractility + vasodilates, including pulmonary — useful if RV dysfunction).[6]
Fluid responsiveness must be assessed before inotropes. Don't give inotrope if patient is still fluid-responsive (still needs fluid). Assess: passive leg raise, IVC ultrasound, cardiac output monitoring. If fluid-responsive → give fluid first. If NOT fluid-responsive (or still hypoperfused after fluid) → add inotrope. Avoid fluid overload — worsens outcomes.[13]
Mortality is HIGHER with SICM. SICM is a marker of SEVERE sepsis (more systemic inflammation). Mortality with SICM: 40-70% (vs 20-30% without SICM). BUT: SICM itself is REVERSIBLE — mortality is driven by OVERALL sepsis severity, not the cardiac dysfunction alone.[1][8]
Echocardiography is the key diagnostic tool. (1) Assess EF (reduced in SICM). (2) LV size (dilated). (3) RV function (may be impaired). (4) Regional wall motion (should be GLOBAL — if regional, consider ischaemia). (5) Diastolic function (E/e' ratio). (6) Volume status (IVC). (7) Pericardial effusion (exclude tamponade). Serial echo (monitor recovery).[4]
SICM vs cardiogenic shock — critical distinction. SICM: WARM shock (vasodilated, low SVR, warm extremities), source of infection, REVERSIBLE, high lactate (sepsis). CARDIOGENIC: COLD shock (constricted, high SVR, cold extremities), cardiac cause (MI, myocarditis), may be permanent, elevated filling pressures. Treatment differs: SICM → vasopressors + treat sepsis; cardiogenic → inotropes + revascularisation (if ischaemic).[5]
Persistent LV dysfunction after sepsis recovery — consider alternative. If EF does NOT recover within 7-10 days: (1) Pre-existing cardiomyopathy (unmasked by sepsis). (2) Ischaemic heart disease (MI during sepsis — plaque rupture or type 2). (3) Myocarditis (viral — may coexist with sepsis). (4) Takotsubo (stress cardiomyopathy — may be triggered by sepsis). (5) Sepsis-induced permanent damage (rare — if severe, prolonged). Investigate: coronary angiography, cardiac MRI, follow-up echo.[1]

Red flags

Critical septic cardiomyopathy red flags

New LV dysfunction in septic shock → SICM (reversible, treat sepsis + inotrope).[1]
Low cardiac output despite vasopressors → add inotrope (dobutamine/milrinone).[6]
RV dysfunction in sepsis → often missed, contributes to hypoxaemia + shock.[4][17]
Troponin elevated in sepsis → usually type 2 MI or SICM (not necessarily type 1 — don't automatically PCI).[4][12]
SICM is REVERSIBLE — EF recovers in 7-10 days (if sepsis treated).[1]
Persistent EF depression beyond day 10 → reconsider ischaemia, myocarditis, takotsubo, pre-existing cardiomyopathy; arrange coronary angiography ± cardiac MRI.[1]
Rising BNP/NT-proBNP with falling EF → worsening SICM; reassess haemodynamics, escalate inotrope, consider mechanical support if refractory.[14]
Biventricular failure + refractory hypoxaemia → severe SICM with RV failure; consider inhaled pulmonary vasodilator, lung-protective ventilation, early MDT discussion for mechanical circulatory support.[6]

Prognosis

Outcomes of sepsis-induced cardiomyopathy (Parker/Parrillo 1990, Hasegawa 2023 meta-analysis)

Classic study (Parrillo/Parker, Annals of Internal Medicine 1990) + modern systematic review and meta-analysis (Hasegawa et al, J Intensive Care Med 2023):[5][8]

Prevalence in septic shock: 40-60% (echocardiographic evidence of LV systolic dysfunction); diastolic dysfunction present in up to 70%
Mortality WITH SICM: significantly higher than septic shock without SICM (pooled OR ~1.9 in the Hasegawa 2023 meta-analysis)
EF recovery: 60-80% of survivors recover EF within 7-10 days
Persistent LV dysfunction: 20-40% (may have pre-existing cardiomyopathy or permanent damage)
RV dysfunction: present in 30-50% of septic shock patients (often coexists with LV, worsens prognosis)
Troponin elevation: 50-80% of septic shock patients (correlates with severity, not necessarily ischaemia)[12]

KEY: SICM is a MARKER of severity (sicker patients), not necessarily the CAUSE of death. Treat the sepsis, support the heart, expect recovery.

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Pathophysiology — deep dive

Pathophysiology of septic cardiomyopathy: cytokine-mediated myocardial depression, nitric oxide, mitochondrial dysfunction, mixed distributive and cardiogenic shock — FigureCytokines, NO, and mitochondrial stunning depress myocardium — often global and reversible, distinct from coronary occlusion until proven otherwise.

SICM is a functional, cytokine-mediated myocardial injury — not an ischaemic or structurally destructive one. The depression is mediated by soluble factors and reversible cellular dysfunction (mitochondrial, receptor, microvascular) rather than myocyte necrosis, which is why EF recovers when the septic source is controlled. Five overlapping mechanisms account for most of the contractile deficit.[1][6]

1. Circulating myocardial depressant substances

The seminal observation: serum from septic shock patients with reduced EF, when applied to isolated rat myocytes in vitro, depresses the extent and velocity of shortening; serum from septic patients without cardiac depression, or from non-septic critically ill controls, does not. The depressant activity is titratable, heat-labile, and trackable with the patient's clinical course — appearing within 24-48 h of shock onset and disappearing as the patient recovers, paralleling EF normalisation. This is the mechanistic basis for the reversibility of SICM.[3][5]

Fractionation and neutralisation identified the depressants as pro-inflammatory cytokines:[7]

Tumour necrosis factor-α (TNF-α / cachectin) — the first identified; directly reduces myocyte contractility within minutes via sphingomyelinase → ceramide → negative inotropy, and via nitric oxide synthase induction. Plasma TNF correlates with the degree of myocardial depression.
Interleukin-1β (IL-1β) — synergistic with TNF-α; depresses contractility more slowly (hours) via autocrine NO and β-receptor uncoupling.
Interleukin-6 (IL-6) — later peak (sustained phase); reduces contractility via NO/superoxide and downregulates β-adrenergic signalling.

Kumar et al (J Exp Med 1996) proved causality: immunoneutralisation of TNF-α and IL-1β abolished the in vitro depressant effect of septic human serum on myocytes, establishing these two cytokines as the principal mediators.[7]

2. Nitric oxide (NO) pathway

NO is the downstream effector of much of the cytokine-mediated depression. Inducible NO synthase (iNOS / NOS2) is upregulated in cardiac myocytes and the vascular endothelium by TNF-α, IL-1β and endotoxin, producing sustained, high-output NO. NO activates soluble guanylate cyclase → ↑cGMP → ↓myofilament calcium responsiveness → negative inotropy. NO also reacts with superoxide to form peroxynitrite (ONOO⁻), which directly damages contractile proteins, mitochondrial enzymes and membrane lipids. The net effect: reduced contractility, impaired relaxation, and mitochondrial damage.[16]

3. Mitochondrial dysfunction

In sepsis, myocardial oxygen extraction is preserved but oxygen utilisation is impaired — there is pathological oxygen supply-demand uncoupling at the cellular level. Mitochondria in septic myocardium show:[1][6]

Complex I/II/III dysfunction → reduced oxidative phosphorylation and ATP synthesis
Mitochondrial permeability transition pore (mPTP) opening → cytochrome c release, apoptosis
Oxidative/nitrosative stress (superoxide, peroxynitrite) damaging the electron transport chain
Mitochondrial autophagy (mitophagy) failure → accumulation of damaged organelles

The result is a state of cellular energetic failure ("cytopathic hypoxia") — the myocyte cannot generate ATP even in the presence of adequate oxygen, mimicking hibernation. This is central to the reversible, non-ischaemic nature of SICM: the cell is alive but functionally dormant. [1]

4. Beta-adrenergic receptor downregulation / desensitisation

Sepsis induces β-adrenergic receptor desensitisation in the myocardium: receptor density falls, receptor-G-protein-adenylate cyclase coupling is uncoupled, and downstream cAMP generation is blunted. Mechanisms include elevated circulating catecholamines (agonist-induced desensitisation), cytokine-mediated (TNF/IL-1) receptor phosphorylation, and increased G-protein-coupled receptor kinase (GRK) activity. Clinically this manifests as blunted contractile reserve and reduced responsiveness to exogenous catecholamines — one rationale for phosphodiesterase inhibitors (milrinone), which act downstream of the receptor, and for the calcium-sensitiser levosimendan.[6]

5. Coronary microcirculatory dysfunction

Although global coronary blood flow is usually maintained or increased in septic shock, there is microcirculatory maldistribution: capillary leak, endothelial activation, leucocyte plugging, microthrombi and altered arteriolar tone create patchy hypoperfusion despite adequate macrovascular flow. Coupled with the increased oxygen demand of tachycardia and high inotrope use, this produces regional supply-demand mismatch (a substrate for type 2 MI and troponin leak).[1]

Mechanisms of myocardial depression in sepsis — at a glance

Mechanism	Key mediator(s)	Cellular effect	Clinical correlate
Circulating depressant substances	TNF-α, IL-1β, IL-6	↓ Myofilament shortening (ceramide, sphingomyelinase)	Global hypokinesis; reversible as cytokines clear
Nitric oxide / iNOS	NO, cGMP, peroxynitrite	↓ Calcium responsiveness; mitochondrial damage	Negative inotropy; impaired relaxation
Mitochondrial dysfunction	Electron transport chain ↓, mPTP opening	↓ ATP synthesis ("cytopathic hypoxia")	Hibernating, viable but functionally dormant myocyte
β-receptor desensitisation	GRK, receptor phosphorylation	↓ cAMP, blunted adrenergic signalling	Reduced catecholamine responsiveness
Microcirculatory dysfunction	Endothelial activation, capillary leak	Patchy hypoperfusion, regional ischaemia	Troponin leak (type 2 MI substrate)

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Pathophysiology pearls — examiner-favourite distinctions

SICM is REVERSIBLE because the mechanism is functional, not structural. There is no myocyte necrosis (unlike infarction) — the depression is mediated by soluble cytokines and reversible mitochondrial/receptor dysfunction. EF recovers as the cytokine load clears.[3][7]
TNF-α and IL-1β are the principal depressant cytokines (Kumar 1996). Immunoneutralising both abolished the depressant effect of septic serum on isolated myocytes. IL-6 sustains the depression. Know this triplet for the viva.[7]
The serum-transfer experiment is the keystone evidence. Parrillo (1985) showed septic serum depresses healthy myocytes in vitro; the activity tracks the patient's EF over time. This proves the depressant is circulating and reversible.[3]
Nitric oxide is the final common effector. iNOS-derived NO → cGMP → ↓ calcium sensitivity, plus peroxynitrite oxidative injury. This is why animal iNOS-knockout models are relatively protected, and why non-selective NOS inhibition (in older trials) failed — you need eNOS preserved.[16]
"Cytopathic hypoxia" explains the paradox of preserved SvO₂ with organ failure. Mitochondria cannot use oxygen → venous saturation stays high while ATP production fails. The heart looks "well oxygenated" but is energy-starved.[6]
β-receptor desensitisation is why escalating catecholamines have diminishing returns. Receptor downregulation + uncoupling blunts the response to dobutamine/noradrenaline. Milrinone (PDE-3 inhibitor) bypasses the receptor — rationale for combination/independent inotropy.[6]
The depression is GLOBAL, not regional. Cytokines bathe the whole myocardium → diffuse hypokinesis ± dilatation. A regional wall motion abnormality in a septic patient is a red flag for concomitant ischaemia / takotsubo, not pure SICM.[4]

Diagnosis

SICM is a clinical-echocardiographic diagnosis made in a patient with septic shock who develops new biventricular dysfunction not explained by ischaemia or pre-existing disease. There is no single pathognomonic test — the diagnosis integrates (1) the clinical context (septic shock), (2) echocardiographic findings, (3) cardiac biomarkers, and (4) exclusion of competing diagnoses. [1]

Echocardiography — the cornerstone

Bedside echocardiography (focus TTE/FOCUS or comprehensive TTE) is first-line and should be performed early (within 6 h of shock recognition) and repeated serially (every 24-48 h) to track recovery.[4]

Findings supporting SICM:

Reduced LV ejection fraction (EF) — classically <50%, often 30-40% in active SICM. May be profoundly depressed in severe cases.
LV dilatation — increased LVEDD/LVEDV; the heart dilates to preserve stroke volume via Starling's law (adaptive).
Global hypokinesis — diffuse, not regional. Regional wall motion abnormality → suspect ischaemia.
RV dysfunction — reduced TAPSE (<17 mm), RV dilatation, tricuspid annular plane systolic excursion, tricuspid regurgitation, paradoxical septal motion. Present in 30-50%.[17]
Diastolic dysfunction — impaired relaxation (Grade I-III). Assess E/A ratio, E/e' ratio (E/e' >14 suggests elevated LV filling pressure), left atrial volume index, deceleration time. Diastolic dysfunction is independently associated with mortality.
Hyperdynamic / normal EF in early sepsis — does NOT exclude SICM; diastolic dysfunction or reduced strain may be the only early clue.

Echocardiographic parameters in SICM — what to measure and why

Parameter	Abnormal in SICM	Cut-off / finding	Significance
LV ejection fraction (LVEF)	Systolic dysfunction	<50% (often 30-40%)	Hallmark; recoverable in 7-10 days
Global longitudinal strain (GLS)	Sub-endocardial dysfunction (precedes EF fall)	Less negative than −18% (−16% to −18%)	Most sensitive marker; detects dysfunction with "normal" EF
LVEDD / LVEDV	LV dilatation	LVEDD >5.8 cm (M, simplified)	Adaptive Starling compensation
RV function (TAPSE, FAC, S')	RV dysfunction	TAPSE <17 mm	Biventricular disease; worse prognosis
E/e' ratio	Diastolic dysfunction / ↑ filling pressure	>14 suggests elevated LV filling pressure	Independent mortality predictor
IVC size/collapsibility	Volume status & responsiveness	Collapsible (>50%) → fluid responsive	Guide fluid vs inotrope decision
Regional wall motion	Should be ABSENT in SICM	RWM abnormality → suspect ischaemia/takotsubo	Key differentiator

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Global longitudinal strain (GLS) — the sensitive early marker

Speckle-tracking global longitudinal strain detects subclinical myocardial dysfunction before EF falls, because longitudinal sub-endocardial fibres are the most vulnerable to cytokine/ischaemic injury. GLS is reduced (less negative) in SICM even when EF reads "normal", making it the most sensitive echocardiographic marker and a powerful prognostic indicator — worsening GLS correlates with mortality even after EF correction. GLS normalisation lags clinical recovery, so follow trends rather than single values.[4][15]

Cardiac biomarkers

Troponin (hs-cTnT/cTnI) — elevated in 50-80% of septic shock patients; reflects cytokine-mediated myocyte injury, microvascular dysfunction, type 2 MI and direct oxidative damage (not plaque rupture). A meta-analysis (Sheyin 2015) showed troponin elevation confers significantly higher mortality (OR ~2) in sepsis.[12] Use trends, not a single value, and interpret in context — do not reflexively coronary-angiogram an isolated troponin rise.
BNP / NT-proBNP — elevated in SICM from ventricular wall stress; correlates with the severity of dysfunction and prognosis. Rising BNP with falling EF suggests worsening SICM; falling BNP parallels recovery.[14] Useful to distinguish cardiogenic from septic pulmonary oedema and to follow response to therapy.

Cardiac MRI — for atypical or persistent cases

Cardiac MRI is reserved for cases where the diagnosis is unclear or EF fails to recover by day 10-14, to distinguish SICM from myocarditis (oedema, late gadolinium enhancement in a non-coronary pattern), ischaemia (subendocardial/transmural LGE in a coronary distribution), or takotsubo (apical ballooning, typical oedema). In SICM itself, MRI typically shows little or no late gadolinium enhancement (consistent with functional, non-necrotic injury), though small focal oedema may be seen — a useful negative finding that supports the diagnosis.[15]

Imaging modalities in suspected SICM

Modality	Role	Strengths	Limitations
Bedside TTE / FOCUS	First-line, serial	Immediate, repeatable, no transport; assesses EF, RV, IVC, effusion	Operator-dependent; visual EF less precise
Comprehensive TTE + GLS	Definitive echo assessment	Speckle-tracking GLS detects subclinical dysfunction; diastolic assessment	Needs experienced sonographer/vendor
Transoesophageal echo (TOE)	If TTE poor windows / valvular query	High image quality; intraoperative	Semi-invasive; not first-line
Cardiac MRI	Persistent/atypical dysfunction	Tissue characterisation (oedema, LGE); excludes myocarditis/ischaemia	Transport of critically ill; not acute
Coronary angiography	If ischaemia suspected (regional WMA, type 1 MI)	Defines coronary anatomy; therapeutic (PCI)	Invasive; not for isolated troponin rise

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Diagnostic workup of suspected sepsis-induced cardiomyopathy

Suspect — septic shock with new cardiac dysfunction, rising lactate despite resuscitation, hypoxaemia, oliguria, cool peripheries OR unexpectedly low SvO₂
Early bedside TTE (≤6 h) — EF, LV size, RV function (TAPSE), diastolic (E/e'), IVC, pericardial effusion, regional wall motion
Biomarkers — troponin (baseline + trend), BNP/NT-proBNP, lactate, venous/arterial blood gas
Compare to baseline — any prior echo, ECG, troponin (pre-existing cardiomyopathy vs new)
Classify haemodynamics — fluid-responsive vs not; warm (vasoplegic) vs cold (low output) shock phenotype
If EF depressed and fluid-resuscitated but still hypoperfused → add inotrope (dobutamine first; milrinone if RV dysfunction/vasoconstriction)
Serial echocardiography every 24-48 h — track EF/GLS recovery; daily biomarker trend
If EF NOT recovering by day 10-14 → cardiac MRI ± coronary angiography to exclude ischaemia, myocarditis, takotsubo, pre-existing cardiomyopathy

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Diagnosis pearls — what the examiner wants to hear

Echo is the cornerstone, but normal EF does NOT exclude SICM. Diastolic dysfunction and reduced global longitudinal strain may be the only early signs. Always measure GLS if available — it is more sensitive than EF and a stronger prognostic marker.[4]
A regional wall motion abnormality is a red flag for ischaemia, not SICM. SICM causes global hypokinesis ± dilatation. Discrete, territory-based hypokinesis → coronary angiography to exclude type 1 MI/takotsubo.[5]
Always assess BOTH ventricles. RV dysfunction (TAPSE, RV FAC, S') is present in up to half and worsens prognosis, yet is the most commonly missed bedside finding.[17]
Troponin elevation predicts mortality (Sheyin meta-analysis OR ~2), but does not equal type 1 MI. Use trends; correlate with echo; do not reflexively cath lab a septic patient with an isolated troponin.[12]
BNP/NT-proBNP tracks SICM severity and recovery. Rising BNP + falling EF = worsening disease; falling BNP = recovery. Useful adjunct to serial echo.[14]
Cardiac MRI is the tie-breaker for non-recovering EF. Absent late gadolinium enhancement supports functional SICM; subendocardial LGE → ischaemia; mid-wall/subepicardial LGE + oedema → myocarditis.[15]
Hyperdynamic EF in early sepsis is the opposite phenotype and a pitfall. A "tight", hypercontractile LV with small cavity and low SVR is also abnormal in septic shock — do not be reassured by EF >70%.[6]

Differentiating SICM from pre-existing cardiomyopathy and mimics

The single most important diagnostic decision is whether the cardiac dysfunction is new and sepsis-related (SICM, reversible) versus pre-existing (unmasked by sepsis) or an alternative acute cardiomyopathy (ischaemic, myocarditis, takotsubo) — because the management, prognosis and counselling differ fundamentally. [1]

Key differentiators:

History — any prior echo, heart failure admission, IHD, valve disease, cardiotoxic chemotherapy, familial cardiomyopathy. A normal prior EF strongly supports SICM.
ECG — Q waves, old infarct, persistent ST changes suggest chronic/pre-existing disease. Diffuse non-specific changes common in both sepsis and myocarditis.
Echo pattern — SICM: global hypokinesis ± dilatation, normal valve structure, little/no LVH. Pre-existing: regional WMA (post-MI), marked LVH (hypertensive/HFpEF), restrictive/hypertrophic phenotypes, valvular disease.
Wall motion — regional → ischaemia/takotsubo; global → SICM.
Takotsubo — apical ballooning with basal hyperkinesis, often triggered by sepsis; can coexist with SICM and is itself reversible.
Biomarker trajectory — SICM: troponin mild-moderate, rises then falls with recovery. Acute MI: steep rise, territory echo. Myocarditis: troponin often markedly elevated, ECG changes, viral prodrome.
Coronary angiography — the gold-standard discriminator when ischaemia is plausible (regional WMA, type 1 MI features).
Cardiac MRI — tissue characterisation to distinguish myocarditis (oedema + mid-wall/subepicardial LGE) from SICM (minimal LGE) and ischaemia (subendocardial LGE).[15]

SICM vs cardiogenic shock vs takotsubo vs myocarditis vs pre-existing cardiomyopathy

Feature	SICM	Cardiogenic shock (AMI)	Takotsubo	Acute myocarditis	Pre-existing cardiomyopathy
Context	Septic shock	Ischaemic event	Emotional/physical stress (incl. sepsis)	Viral prodrome	Chronic HF history
SVR	Low (vasoplegic, warm)	High (cold)	Variable	Variable	Variable
EF	Reduced, recoverable	Reduced, regional WMA	Reduced, apical ballooning	Reduced, global	Chronically reduced
Wall motion	Global hypokinesis	Regional (coronary)	Apical ballooning, basal hyperkinesis	Global, often patchy	Regional or global
LGE (MRI)	Minimal/absent	Subendocardial/transmural	Apical/mid-cavity oedema	Mid-wall/subepicardial + oedema	Variable (often established)
Troponin	Mild-moderate, trend	Marked, rise-fall	Moderate	Often markedly high	Variable
Reversibility	Yes, 7-10 days	Depends on revascularisation	Yes, days-weeks	Variable	Usually no
First treatment	Noradrenaline + treat sepsis + inotrope	Revascularise + MCS	Supportive, treat trigger	Immunosuppression (selected)	Guideline HF therapy

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Differentiation pearls — high-stakes distinctions

The single most useful piece of information is a prior echocardiogram. A normal EF within the last 1-2 years in a patient now in septic shock with reduced EF is strong evidence for SICM (reversible). Absent baseline → assume SICM if global dysfunction, but stay alert to alternatives if recovery is delayed.[1]
Regional wall motion = ischaemia until proven otherwise. Territory-based hypokinesis does not fit cytokine-mediated global depression; pursue coronary angiography.[5]
Takotsubo can masquerade as SICM (and vice versa). Both are reversible and can be triggered by sepsis. The differentiator is the apical ballooning + basal hyperkinesis morphology of takotsubo vs the global, diffuse hypokinesis of SICM.[6]
Troponin magnitude is a clue, not a rule. Very high troponin with global dysfunction and a viral prodrome favours myocarditis; moderate troponin in fulminant sepsis favours SICM. But there is heavy overlap — use MRI when uncertain.[12][15]
A patient with known severe LV dysfunction who then gets sepsis does NOT have SICM — they have chronic cardiomyopathy decompensated by sepsis. The distinction matters for prognosis and for whether to expect recovery.[1]
Persistent EF depression beyond 10-14 days mandates reassessment. Recovery that does not occur on schedule is the strongest clue that the diagnosis is wrong — escalate to MRI ± angiography.[1]

Reversibility and natural history

The natural history of SICM is one of the most exam-friendly and clinically reassuring aspects of the condition. The dysfunction is acquired rapidly (within 24-48 h of shock onset), is maximal at days 2-3, and recovers over 7-10 days in survivors as the septic source is controlled and the cytokine load clears.[1][5]

Timeline:

Onset (Day 0-2): EF falls within hours-days of shock; troponin/BNP rise; LV dilates; RV dysfunction may appear.
Nadir (Day 2-4): maximal depression; inotrope requirement greatest; highest mortality risk.
Recovery (Day 4-10): EF climbs back towards baseline as cytokines clear and mitochondrial function recovers; inotropes wean; biomarkers fall.
Resolution (Day 7-10+): 60-80% of survivors regain a normal (or near-normal) EF. A minority (20-40%) have persistent dysfunction — usually pre-existing cardiomyopathy unmasked by sepsis, or (rarely) permanent sepsis-induced injury. [1]

Caveat: recovery presumes adequate source control and antimicrobial therapy. If the septic drive persists (undrained collection, resistant organism), SICM persists and may progress. [1]

Reversibility data — Parker/Parrillo 1990 and modern series

Parker/Parrillo (Ann Intern Med 1990): in survivors of septic shock, depressed EF recovered to normal within 7-10 days; non-survivors had a paradoxically higher early EF (less depression) — the so-called "reversal" finding, since explained by inability to mount the adaptive LV dilatation.[5]
Modern echo series: EF recovery in 60-80% of survivors by day 7-10; persistent LV dysfunction in 20-40%.
Diastolic dysfunction (E/e') recovery often lags systolic recovery by days — do not be alarmed by persistent diastolic impairment if EF is normalising.
GLS recovery lags EF recovery — follow GLS trends for completeness.

Reversibility pearls — what to expect and when to worry

Expect recovery by day 7-10 in survivors. If it is not happening, reassess — either the sepsis is uncontrolled or the diagnosis is wrong.[1]
The Parker "reversal" paradox is exam gold. Non-survivors had a higher early EF because they were too sick to mount adaptive LV dilatation; survivors' EF fell (dilated) then recovered. Do not over-read a "good" EF in fulminant septic shock.[5]
Diastolic recovery lags systolic recovery. Persisting high E/e' after EF normalises is expected and not, by itself, a sign of failure.[2]
RV dysfunction recovers alongside LV, but RV failure is a stronger independent mortality predictor. Persistent RV dysfunction at day 7 is a poor sign.[17]
The driver of mortality is the underlying sepsis, not the EF number. A patient can die of septic shock with a recovering EF. Do not equate EF normalisation with resolution of sepsis.[8]
Recovery is the rule, but a small subset develop persistent dysfunction. These are usually patients with unmasked pre-existing disease, dual pathology (myocarditis/takotsubo), or profound prolonged shock. Investigate, do not simply label "slow SICM".[1]

Management

The principles of SICM management mirror those of septic shock, with cardiac-specific layers added once volume status is addressed. Treat the sepsis first — source control and antibiotics are the definitive therapy for the cardiac depression.[11]

Step 1 — Resuscitate the sepsis (Surviving Sepsis Campaign 2021)

Antibiotics within 1 hour of recognition; broad-spectrum, source-directed.
Source control as soon as practical (drainage, debridement, device removal).
Early crystalloid — at least 30 mL/kg in the first 3 h for septic shock with hypoperfusion, but titrated dynamically to dynamic fluid-responsiveness metrics. The 2021 SSC weakened the fixed 30 mL/kg recommendation precisely because of harm from injudicious fluid in non-responders.[11]

Step 2 — Assess fluid responsiveness BEFORE giving more fluid

Giving inotropes to a hypovolaemic patient worsens outcomes; giving more fluid to a non-responder causes oedema, worsens gas exchange, raises intra-abdominal pressure, and (in SICM) precipitates pulmonary oedema and RV overload. Test responsiveness with:[13]

Passive leg raise (PLR) — the best bedside test (sensitivity/specificity ~85%); starts at 45° semi-recumbent → flat + legs elevated 45° for 60-90 s; a ≥10% rise in cardiac output/stroke volume (or pulse pressure/variations) = responder. Monnet's meta-analysis confirms PLR outperforms static indices.[13]
IVC collapsibility (>50% collapse in spontaneously breathing; distensibility >18% in ventilated) — quick, qualitative.
Stroke volume variation / pulse pressure variation — in fully ventilated, deeply sedated patients with closed chest.
Fluid challenge — 250-500 mL bolus with real-time CO measurement.
Echocardiographic SV assessment (LVOT VTI) before/after PLR.

Decision: responder → give fluid (small aliquots, recheck). Non-responder or hypoperfusion persists after adequate fluid → move to vasopressors ± inotropes. [1]

Tests of fluid responsiveness in septic shock

Test	How performed	Threshold for "responder"	Pitfalls
Passive leg raise (PLR)	Semi-recumbent 45° → legs up 45°, trunk flat, 60-90 s	ΔSV or ΔCO ≥10%	Start from 45° (not flat); auto-transfuse ~300 mL
IVC collapsibility (spontaneous)	M-mode subxiphoid	>50% collapse	Unreliable if mechanically ventilated or high PEEP
IVC distensibility (ventilated)	M-mode	>18% distensibility	Needs fully controlled ventilation, closed chest
SVV / PPV	Arterial/pulse-contour	>12-13%	Only valid in deep sedation, controlled ventilation, regular rhythm
Mini fluid challenge	50-250 mL bolus + real-time CO/VTI	ΔSV ≥10%	Needs CO monitor/echo; transient

[1]

Step 3 — Vasopressors (noradrenaline first-line)

Target MAP ≥65 mmHg (lower acceptable if chronic HTN controlled; individualise).[11]

Noradrenaline (norepinephrine) FIRST-LINE — α-1 vasoconstriction restores SVR + modest β-1 inotropy. Even with SICM it is preferred: it improves coronary perfusion pressure and supports the depressed myocardium without the arrhythmia burden of dopamine.
Vasopressin (0.01-0.04 U/min) — add as second agent to reduce noradrenaline dose (catecholamine-sparing); fixed low dose. Not a first-line solo agent.
Adrenaline (epinephrine) — alternative/add-on; more arrhythmias, ↑lactate (β-2 glycolysis), but potent inotrope + vasoconstrictor.
Dopamine — AVOID unless specifically bradycardic shock. SOAP II (De Backer, NEJM 2010): dopamine vs noradrenaline showed no mortality difference overall but significantly more arrhythmias with dopamine (mostly atrial fibrillation), and a subgroup signal of worse outcome in cardiogenic shock.[9]

Step 4 — Inotropes (when low cardiac output persists)

Add an inotrope when there is ongoing hypoperfusion (rising lactate, oliguria, mottled skin, low SvO₂, cold peripheries) despite adequate fluid resuscitation and adequate MAP, and/or echo shows reduced EF with low cardiac output.[6][11]

Dobutamine — β-1 agonist (with some β-2). Increases contractility and CO, modest vasodilation (can drop SVR/MAP — usually co-administered with noradrenaline). First-line inotrope in SICM with low output. Start 2.5-5 µg/kg/min, titrate.
Milrinone — PDE-3 inhibitor; ↑cAMP independent of β-receptor (useful given β-desensitisation in sepsis); inotrope + lusitrope + vasodilator, including pulmonary vasodilation → preferred when RV dysfunction or pulmonary hypertension coexists. Longer half-life (~2.5 h) — harder to titrate acutely; can cause hypotension (often need noradrenaline concurrently).
Levosimendan — calcium sensitiser; improves contractility without rising intracellular calcium (theoretically less arrhythmia/O₂ demand). LeoPARDS trial (Antcliffe, ICM 2019) found NO benefit on SOFA-derived organ dysfunction or mortality in septic shock with biochemical cardiac dysfunction; not routinely recommended.[10]

Inotropes in sepsis-induced cardiomyopathy

Agent	Mechanism	Haemodynamic effect	Best use in SICM	Key cautions
Dobutamine	β-1 (±β-2) agonist	↑CO, ↓SVR (modest), ↑HR	First-line; LV low output	Tachyarrhythmia; ↑myocardial O₂ demand; can drop MAP
Milrinone	PDE-3 inhibitor → ↑cAMP	↑CO, ↓SVR + ↓PVR	RV dysfunction / pulmonary HTN; β-desensitised patient	Long t½; hypotension; often need noradrenaline
Levosimendan	Calcium sensitiser	↑CO, vasodilation	NOT routine (LeoPARDS negative)	Hypotension; cost; no outcome benefit
Adrenaline	α/β agonist	↑CO + ↑SVR (high dose)	Refactory shock with low CO	↑Lactate (β-2), arrhythmias, ↑O₂ demand
Dopamine	Dose-dependent D/α/β	Variable	Only if bradycardic shock	SOAP II: more arrhythmias; AVOID generally

[1]

Step 5 — Avoid excessive fluid (a recurring, lethal error)

Fluid overload worsens outcomes in septic shock and is doubly harmful in SICM: it precipitates pulmonary oedema, worsens gas exchange, raises intra-abdominal pressure (renal impairment), and overloads a depressed RV (TR, low LV preload from septal shift). Strategies:[11][13]

Deresuscitate — once stable, achieve negative fluid balance with diuretics (furosemide) or RRT if needed.
Late shock = less fluid, more vasopressor/inotrope. The classic "give fluid, give more fluid" reflex kills in SICM.
Monitor cumulative fluid balance daily; target even-to-negative balance after the first 24-48 h.

Step 6 — Mechanical circulatory support (rare, refractory cases)

In the small subset with refractory SICM (biventricular failure, persistent low output despite maximal inotrope + vasopressor), short-term mechanical support — IABP (limited in vasoplegia), VA-ECMO, or Impella — may bridge to recovery. This is an MDT decision and a bridge-to-recovery/decision, not destination therapy; outcome is dictated by the underlying sepsis.[6]

Haemodynamic management algorithm for SICM

Resuscitate sepsis — antibiotics <1 h, source control, initial 30 mL/kg crystalloid (titrate)
Assess volume status + fluid responsiveness — PLR, IVC, SVV/PPV, echo VTI. If responsive → 250-500 mL aliquots, reassess
Start vasopressor — noradrenaline first-line; target MAP ≥65; add vasopressin 0.03 U/min if escalating
Reassess perfusion — lactate trend, SvO₂, urine output, skin temp, echo EF/CO
If hypoperfusion persists + reduced EF/low CO → add dobutamine 2.5-5 µg/kg/min (titrate to CO/SvO₂ 65-70%); ensure adequate MAP with noradrenaline
If RV dysfunction / pulmonary HTN → add/switch to milrinone (with noradrenaline for MAP)
Avoid dopamine (SOAP II: more arrhythmias); do NOT use levosimendan routinely (LeoPARDS negative)
Stop fluids once euvolaemic — deresuscitate with diuretics; track cumulative balance
Serial echo + biomarkers — expect EF recovery by day 7-10; if not, reassess diagnosis
Refractory low output despite maximal therapy → MDT for short-term MCS (VA-ECMO/Impella) as bridge to recovery

[1]

Management pearls — what actually changes outcome

Source control is the definitive therapy for SICM. The heart recovers when the cytokine load clears — driven by drainage, debridement, device removal, and targeted antibiotics, not by inotropes. Never delay source control for investigations.[11]
Always test fluid responsiveness before more fluid or an inotrope. PLR is the best bedside test; giving dobutamine to a dry patient or fluid to a non-responder both worsen outcomes.[13]
Noradrenaline is first-line even when EF is reduced. It improves coronary perfusion pressure and supports the depressed myocardium with fewer arrhythmias than dopamine. The low SVR of septic shock needs correcting regardless of EF.[9]
Dobutamine drops MAP — co-administer with noradrenaline. β-2 vasodilation can cause precipitate hypotension in a vasoplegic patient; do not start dobutamine without a vasopressor running.[6]
Milrinone is the inotrope of choice when RV dysfunction coexists. Its pulmonary vasodilation reduces RV afterload, and its PDE-3 mechanism bypasses β-receptor desensitisation. Beware the long half-life and hypotension.[6]
Levosimendan does NOT improve outcomes in septic shock (LeoPARDS). Despite elegant mechanistic rationale (calcium sensitiser, less O₂ demand), the trial was negative — do not use routinely.[10]
Dopamine causes more arrhythmias than noradrenaline (SOAP II). Reserve it for the rare bradycardic septic shock patient.[9]
Fluid overload is a recurring, preventable killer in SICM. Late shock should be managed with less fluid and more vasopressor/inotrope; deresuscitate early. A flooded RV fails fast.[11][13]
Target SvO₂/ScvO₂ 65-70% as a perfusion goal once fluid-resuscitated. Low SvO₂ despite adequate MAP and volume = low CO = add inotrope; this is the physiological basis for dobutamine in SICM.[6]
Refractory SICM may need short-term MCS. VA-ECMO or Impella as a bridge-to-recovery is reasonable if the sepsis is treatable; outcome hinges on the underlying source, not the device.[6]

Clinical significance — does myocardial depression drive mortality?

The relationship between SICM and mortality is subtle and exam-critical. Patients with SICM have higher mortality than those without (Hasegawa 2023 meta-analysis pooled OR ~1.9), but the cardiac dysfunction is largely a marker of illness severity (a greater inflammatory burden) rather than the proximate cause of death.[1][8]

Why SICM correlates with mortality:

A larger cytokine load produces both greater myocardial depression AND greater multi-organ failure — SICM flags the sicker patient.
SICM reduces the compensatory rise in cardiac output needed to meet the high septic oxygen demand, worsening tissue hypoxia and lactate.
RV dysfunction (a component of SICM) independently predicts mortality through hypoxaemia and low output.
Severe SICM drives escalating catecholamine use → arrhythmias, myocardial O₂ demand, microvascular insult. [1]

Why SICM itself is not usually the cause of death:

EF recovers in survivors — death from "SICM" alone is rare.
Most deaths are from multi-organ failure secondary to uncontrolled sepsis, with the recovering heart as a bystander.
The Parker "reversal" paradox: non-survivors had less early EF depression (could not dilate adaptively). [1]

Practical implication: treat the sepsis, support the heart (fluids, vasopressors, inotropes), expect recovery — but do not attribute death to "cardiac failure" if the EF is recovering. Persistent search for and control of the septic source is the highest-yield intervention. [1]

Evidence base — landmark trials and meta-analyses

Parrillo/Parker 1990 (Ann Intern Med) — established the reversible, dilated, depressant-substance phenotype of human septic shock cardiomyopathy.[5]
Parrillo 1985 (J Clin Invest) — proved a circulating myocardial depressant substance in septic serum (in vitro myocyte depression).[3]
Kumar 1996 (J Exp Med) — TNF-α and IL-1β are the principal depressant cytokines (immunoneutralisation abolishes the effect).[7]
De Backer 2010 SOAP II (NEJM) — dopamine vs noradrenaline: no overall mortality difference but more arrhythmias with dopamine → noradrenaline first-line.[9]
Antcliffe 2019 LeoPARDS (Intensive Care Med) — levosimendan in septic shock with biochemical cardiac dysfunction: no benefit on organ dysfunction/mortality → not routine.[10]
Hasegawa 2023 (J Intensive Care Med) — systematic review and meta-analysis of SICM prevalence and prognosis: SICM common and associated with higher mortality (OR ~1.9).[8]
Monnet 2016 (Intensive Care Med) — passive leg raising meta-analysis: best bedside fluid-responsiveness test.[13]
Sheyin 2015 (Heart Lung) — troponin elevation in sepsis meta-analysis: prognostic (OR ~2 for mortality).[12]
Evans 2021 (Crit Care Med) — Surviving Sepsis Campaign guidelines: noradrenaline first-line, dopamine to be avoided, inotrope if low CO persisting after adequate fluid + vasopressor.[11]

Clinical-significance pearls — the mortality story

SICM = sicker patient. The depression reflects a larger inflammatory burden; mortality is higher because the sepsis is worse, not (usually) because the heart fails.[1][8]
EF recovery does not equal sepsis resolution. A patient can die with a normalising EF. Keep treating the source.[5]
RV dysfunction is the strongest cardiac mortality predictor in SICM. Biventricular disease carries the worst prognosis; assess RV at every echo.[17]
Troponin and BNP are prognostic biomarkers, not diagnostic gatekeepers. Rising troponin/BNP in septic shock = worse outcome — use them to risk-stratify and follow trends.[12][14]
Catecholamine burden is itself harmful. Escalating inotropes/vasopressors drive arrhythmias and O₂ demand; the goal is the lowest effective dose, achieved by source control + fluid optimisation.[6]
The Parker "reversal" paradox is the single highest-yield viva concept. Survivors' EF fell (adaptive dilatation) then recovered; non-survivors' EF stayed higher (could not dilate). A "good" EF in fulminant septic shock is not reassuring.[5]
Counsel families: the heart usually recovers. Setting the expectation that EF normalises within 7-10 days (if sepsis is controlled) is part of good prognostic communication — but pair it with the message that overall mortality is driven by the sepsis.[1]

Management red flags — errors that harm

Giving more fluid to a non-responder → pulmonary oedema, RV overload, intra-abdominal hypertension. Test responsiveness first.[13]
Starting dobutamine without a vasopressor → precipitate hypotension from β-2 vasodilation.[6]
Using dopamine first-line → more arrhythmias (SOAP II); reserve for bradycardic shock.[9]
Using levosimendan routinely → no outcome benefit (LeoPARDS); do not default to it.[10]
Attributing death to "cardiac failure" when EF is recovering → miss persistent/uncontrolled sepsis. Reassess the source.[1]
Failing to reassess diagnosis if EF does not recover by day 10-14 → miss myocarditis, ischaemia, takotsubo, pre-existing cardiomyopathy.[1][15]
Ignoring RV dysfunction → untreated RV failure drives hypoxaemia and death; assess TAPSE at every echo.[17]

References

[1]Hollenberg SM, Singer M Pathophysiology of sepsis-induced cardiomyopathy Nat Rev Cardiol, 2021.PMID 33473203
[2]Hunter JD, Doddi M Sepsis and the heart Br J Anaesth, 2010.PMID 19939836
[3]Parrillo JE, Burch C, Shelhamer JH, et al A circulating myocardial depressant substance in humans with septic shock. Septic shock patients with a reduced ejection fraction have a circulating factor that depresses in vitro myocardial cell performance J Clin Invest, 1985.PMID 4056039
[4]Sato R, Nasu M A review of sepsis-induced cardiomyopathy J Intensive Care, 2015.PMID 26566443
[5]Parrillo JE, Parker MM, Natanson C, et al Septic shock in humans. Advances in the understanding of pathogenesis, cardiovascular dysfunction, and therapy Ann Intern Med, 1990.PMID 2197912
[6]Kakihana Y, Ito T, Nakahara M, et al Sepsis-induced myocardial dysfunction: pathophysiology and management J Intensive Care, 2016.PMID 27011791
[7]Kumar A, Thota V, Dee L, et al Tumor necrosis factor alpha and interleukin 1beta are responsible for in vitro myocardial cell depression induced by human septic shock serum J Exp Med, 1996.PMID 8642298
[8]Hasegawa D, Ishisaka Y, Sato R, et al Prevalence and Prognosis of Sepsis-Induced Cardiomyopathy: A Systematic Review and Meta-Analysis J Intensive Care Med, 2023.PMID 37272081
[9]De Backer D, Biston P, Devriendt J, et al (SOAP II) Comparison of dopamine and norepinephrine in the treatment of shock N Engl J Med, 2010.PMID 20200382
[10]Antcliffe DB, Santhakumaran S, Whitehouse T, et al (LeoPARDS) Levosimendan in septic shock in patients with biochemical evidence of cardiac dysfunction: a subgroup analysis of the LeoPARDS randomised trial Intensive Care Med, 2019.PMID 31428804
[11]Evans L, Rhodes A, Alhazzani W, et al Executive Summary: Surviving Sepsis Campaign: International Guidelines for the Management of Sepsis and Septic Shock 2021 Crit Care Med, 2021.PMID 34643578
[12]Sheyin O, Davies O, Duan W, Perez X The prognostic significance of troponin elevation in patients with sepsis: a meta-analysis Heart Lung, 2015.PMID 25453390
[13]Monnet X, Marik P, Teboul JL Passive leg raising for predicting fluid responsiveness: a systematic review and meta-analysis Intensive Care Med, 2016.PMID 26825952
[14]Pandompatam G, Kashani K The role of natriuretic peptides in the management, outcomes and prognosis of sepsis and septic shock Rev Bras Ter Intensiva, 2019.PMID 31618357
[15]Muehlberg F, Blaszczyk E, Besse L, et al Characterization of critically ill patients with septic shock and sepsis-associated cardiomyopathy using cardiovascular MRI ESC Heart Fail, 2022.PMID 35587684
[16]Hare JM, Colucci WS Role of nitric oxide in the regulation of myocardial function Prog Cardiovasc Dis, 1995.PMID 7568904
[17]Parker MM, McCarthy KE, Ognibene FP, et al Right ventricular dysfunction and dilatation, similar to left ventricular changes, characterize the cardiac depression of septic shock in humans Chest, 1990.PMID 2295231

[1]

Diagnosis and management of sepsis-induced cardiomyopathy

Recognise — septic shock with cardiac dysfunction (new LV dysfunction, elevated troponin, BNP)
Echocardiography — assess: LV systolic function (EF), LV dilatation, RV function, diastolic function, cardiac output, global longitudinal strain. Compare to baseline (if available)
Distinguish from cardiogenic shock — SICM: WARM shock (vasoplegic), high lactate (sepsis), source of infection, REVERSIBLE. Cardiogenic: COLD shock, elevated filling pressures, ischaemic cause
Treat sepsis — antibiotics within 1h, source control, fluid resuscitation (30 mL/kg crystalloid — but titrate to fluid responsiveness, avoid overload)
Vasopressors — noradrenaline FIRST-LINE (alpha vasoconstriction + modest beta). Target MAP ≥65. Add vasopressin if escalating noradrenaline requirement
Inotropes if low cardiac output — dobutamine (beta-1, increases contractility) or milrinone (PDE inhibitor, reduces afterload, pulmonary vasodilator). Use if: low cardiac output despite adequate volume + vasopressor, ongoing hypoperfusion (lactate, oliguria, mottled skin). Levosimendan NOT routinely recommended (LeoPARDS — no outcome benefit)
Monitor — echocardiography (serial — assess recovery), troponin/BNP trend, lactate clearance, urine output, clinical perfusion
Expect recovery — SICM typically REVERSES within 7-10 days (if sepsis controlled). Persistent dysfunction: consider alternative diagnosis (ischaemia, myocarditis, takotsubo, pre-existing cardiomyopathy)

[1]

Exam practice

SAQ — Septic cardiomyopathy with EF 25 percent and ongoing hypoperfusion

10 minutes · 10 marks

[1]

SAQ — Sepsis-induced cardiomyopathy versus pre-existing cardiomyopathy

10 minutes · 10 marks

[1]

Clinical pearls

High-yield septic cardiomyopathy points for CICM/FFICM exam

SICM is REVERSIBLE. Unlike ischaemic cardiomyopathy (permanent damage), SICM typically RECOVERS within 7-10 days (if sepsis treated successfully). EF returns to baseline in 60-80% of survivors. This REVERSIBILITY is the hallmark — distinguishes from permanent cardiomyopathy.[1]
Circulating myocardial depressant substances are the key mechanism. Sepsis → inflammatory cytokines (TNF-α, IL-1β, IL-6) + nitric oxide (NO) → DIRECTLY DEPRESS myocardial contractility. Evidence: serum from septic patients depresses isolated myocytes in vitro (Parrillo 1985, Kumar 1996). The depression is MEDIATED (not structural — no necrosis). Explains reversibility.[3][7]
Troponin is elevated in SICM (but it's NOT a heart attack). SICM causes myocardial injury (cytokine-mediated, microvascular dysfunction, mitochondrial dysfunction) → troponin leak. This is TYPE 2 MI (supply-demand) or direct cytokine injury — NOT type 1 (atherosclerotic plaque rupture). Don't automatically PCI an elevated troponin in sepsis (assess clinical context).[4][12]
LV dilatation is characteristic. Unlike ischaemic cardiomyopathy (which may have regional wall motion abnormalities), SICM causes GLOBAL hypokinesis + LV DILATATION (increased end-diastolic volume — the heart dilates to maintain stroke volume via Starling mechanism). This is adaptive (dilatation compensates for reduced contractility).[5]
RV dysfunction is also common (and often missed). SICM affects BOTH ventricles. RV dysfunction: reduced TAPSE, RV dilatation, tricuspid regurgitation. Contributes to: hypoxaemia (V/Q mismatch), shock (low output from RV failure). May need: pulmonary vasodilators (inhaled NO), volume management (avoid RV overload), inotropes (milrinone — pulmonary vasodilator + inotrope).[4][17]
Diastolic dysfunction often coexists with systolic. SICM causes impaired relaxation (diastolic dysfunction) as well as reduced contractility (systolic). Elevated filling pressures, reduced compliance. Contributes to pulmonary oedema (despite 'preserved' EF in some). Assess with echocardiography (E/A ratio, E/e' ratio, left atrial size).[2]
Cardiac output in septic shock — 'warm' vs 'cold'. CLASSIC septic shock: HIGH cardiac output (vasodilation → low SVR → compensatory high CO). WITH SICM: cardiac output may be NORMAL or LOW (myocardial depression limits compensatory increase). If LOW output in septic shock → SICM → add inotrope (dobutamine).[6]
Noradrenaline is first-line vasopressor (even with SICM). Noradrenaline: alpha-1 vasoconstriction (restores BP) + modest beta-1 (some contractility). PREFERRED for septic shock (with or without SICM). Dopamine: associated with MORE arrhythmias (SOAP II) — avoid. Vasopressin: add if noradrenaline inadequate.[9]
When to add inotrope in septic shock. Indications: (1) Low cardiac output despite adequate volume + vasopressor (hypoperfusion persists — lactate, oliguria, mottled skin). (2) Echocardiography shows reduced EF + LV dysfunction. (3) SICM confirmed. Drug: DOBUTAMINE (beta-1 — increases contractility, some beta-2 vasodilation) OR MILRINONE (PDE inhibitor — increases contractility + vasodilates, including pulmonary — useful if RV dysfunction).[6]
Fluid responsiveness must be assessed before inotropes. Don't give inotrope if patient is still fluid-responsive (still needs fluid). Assess: passive leg raise, IVC ultrasound, cardiac output monitoring. If fluid-responsive → give fluid first. If NOT fluid-responsive (or still hypoperfused after fluid) → add inotrope. Avoid fluid overload — worsens outcomes.[13]
Mortality is HIGHER with SICM. SICM is a marker of SEVERE sepsis (more systemic inflammation). Mortality with SICM: 40-70% (vs 20-30% without SICM). BUT: SICM itself is REVERSIBLE — mortality is driven by OVERALL sepsis severity, not the cardiac dysfunction alone.[1][8]
Echocardiography is the key diagnostic tool. (1) Assess EF (reduced in SICM). (2) LV size (dilated). (3) RV function (may be impaired). (4) Regional wall motion (should be GLOBAL — if regional, consider ischaemia). (5) Diastolic function (E/e' ratio). (6) Volume status (IVC). (7) Pericardial effusion (exclude tamponade). Serial echo (monitor recovery).[4]
SICM vs cardiogenic shock — critical distinction. SICM: WARM shock (vasodilated, low SVR, warm extremities), source of infection, REVERSIBLE, high lactate (sepsis). CARDIOGENIC: COLD shock (constricted, high SVR, cold extremities), cardiac cause (MI, myocarditis), may be permanent, elevated filling pressures. Treatment differs: SICM → vasopressors + treat sepsis; cardiogenic → inotropes + revascularisation (if ischaemic).[5]
Persistent LV dysfunction after sepsis recovery — consider alternative. If EF does NOT recover within 7-10 days: (1) Pre-existing cardiomyopathy (unmasked by sepsis). (2) Ischaemic heart disease (MI during sepsis — plaque rupture or type 2). (3) Myocarditis (viral — may coexist with sepsis). (4) Takotsubo (stress cardiomyopathy — may be triggered by sepsis). (5) Sepsis-induced permanent damage (rare — if severe, prolonged). Investigate: coronary angiography, cardiac MRI, follow-up echo.[1]

Red flags

Critical septic cardiomyopathy red flags

New LV dysfunction in septic shock → SICM (reversible, treat sepsis + inotrope).[1]
Low cardiac output despite vasopressors → add inotrope (dobutamine/milrinone).[6]
RV dysfunction in sepsis → often missed, contributes to hypoxaemia + shock.[4][17]
Troponin elevated in sepsis → usually type 2 MI or SICM (not necessarily type 1 — don't automatically PCI).[4][12]
SICM is REVERSIBLE — EF recovers in 7-10 days (if sepsis treated).[1]
Persistent EF depression beyond day 10 → reconsider ischaemia, myocarditis, takotsubo, pre-existing cardiomyopathy; arrange coronary angiography ± cardiac MRI.[1]
Rising BNP/NT-proBNP with falling EF → worsening SICM; reassess haemodynamics, escalate inotrope, consider mechanical support if refractory.[14]
Biventricular failure + refractory hypoxaemia → severe SICM with RV failure; consider inhaled pulmonary vasodilator, lung-protective ventilation, early MDT discussion for mechanical circulatory support.[6]

Prognosis

Outcomes of sepsis-induced cardiomyopathy (Parker/Parrillo 1990, Hasegawa 2023 meta-analysis)

Classic study (Parrillo/Parker, Annals of Internal Medicine 1990) + modern systematic review and meta-analysis (Hasegawa et al, J Intensive Care Med 2023):[5][8]

Prevalence in septic shock: 40-60% (echocardiographic evidence of LV systolic dysfunction); diastolic dysfunction present in up to 70%
Mortality WITH SICM: significantly higher than septic shock without SICM (pooled OR ~1.9 in the Hasegawa 2023 meta-analysis)
EF recovery: 60-80% of survivors recover EF within 7-10 days
Persistent LV dysfunction: 20-40% (may have pre-existing cardiomyopathy or permanent damage)
RV dysfunction: present in 30-50% of septic shock patients (often coexists with LV, worsens prognosis)
Troponin elevation: 50-80% of septic shock patients (correlates with severity, not necessarily ischaemia)[12]

KEY: SICM is a MARKER of severity (sicker patients), not necessarily the CAUSE of death. Treat the sepsis, support the heart, expect recovery.

[1]

Pathophysiology — deep dive

1. Circulating myocardial depressant substances

Fractionation and neutralisation identified the depressants as pro-inflammatory cytokines:[7]

Tumour necrosis factor-α (TNF-α / cachectin) — the first identified; directly reduces myocyte contractility within minutes via sphingomyelinase → ceramide → negative inotropy, and via nitric oxide synthase induction. Plasma TNF correlates with the degree of myocardial depression.
Interleukin-1β (IL-1β) — synergistic with TNF-α; depresses contractility more slowly (hours) via autocrine NO and β-receptor uncoupling.
Interleukin-6 (IL-6) — later peak (sustained phase); reduces contractility via NO/superoxide and downregulates β-adrenergic signalling.

2. Nitric oxide (NO) pathway

3. Mitochondrial dysfunction

Complex I/II/III dysfunction → reduced oxidative phosphorylation and ATP synthesis
Mitochondrial permeability transition pore (mPTP) opening → cytochrome c release, apoptosis
Oxidative/nitrosative stress (superoxide, peroxynitrite) damaging the electron transport chain
Mitochondrial autophagy (mitophagy) failure → accumulation of damaged organelles

4. Beta-adrenergic receptor downregulation / desensitisation

5. Coronary microcirculatory dysfunction

Mechanisms of myocardial depression in sepsis — at a glance

Mechanism	Key mediator(s)	Cellular effect	Clinical correlate
Circulating depressant substances	TNF-α, IL-1β, IL-6	↓ Myofilament shortening (ceramide, sphingomyelinase)	Global hypokinesis; reversible as cytokines clear
Nitric oxide / iNOS	NO, cGMP, peroxynitrite	↓ Calcium responsiveness; mitochondrial damage	Negative inotropy; impaired relaxation
Mitochondrial dysfunction	Electron transport chain ↓, mPTP opening	↓ ATP synthesis ("cytopathic hypoxia")	Hibernating, viable but functionally dormant myocyte
β-receptor desensitisation	GRK, receptor phosphorylation	↓ cAMP, blunted adrenergic signalling	Reduced catecholamine responsiveness
Microcirculatory dysfunction	Endothelial activation, capillary leak	Patchy hypoperfusion, regional ischaemia	Troponin leak (type 2 MI substrate)

[1]

Pathophysiology pearls — examiner-favourite distinctions

SICM is REVERSIBLE because the mechanism is functional, not structural. There is no myocyte necrosis (unlike infarction) — the depression is mediated by soluble cytokines and reversible mitochondrial/receptor dysfunction. EF recovers as the cytokine load clears.[3][7]
TNF-α and IL-1β are the principal depressant cytokines (Kumar 1996). Immunoneutralising both abolished the depressant effect of septic serum on isolated myocytes. IL-6 sustains the depression. Know this triplet for the viva.[7]
The serum-transfer experiment is the keystone evidence. Parrillo (1985) showed septic serum depresses healthy myocytes in vitro; the activity tracks the patient's EF over time. This proves the depressant is circulating and reversible.[3]
Nitric oxide is the final common effector. iNOS-derived NO → cGMP → ↓ calcium sensitivity, plus peroxynitrite oxidative injury. This is why animal iNOS-knockout models are relatively protected, and why non-selective NOS inhibition (in older trials) failed — you need eNOS preserved.[16]
"Cytopathic hypoxia" explains the paradox of preserved SvO₂ with organ failure. Mitochondria cannot use oxygen → venous saturation stays high while ATP production fails. The heart looks "well oxygenated" but is energy-starved.[6]
β-receptor desensitisation is why escalating catecholamines have diminishing returns. Receptor downregulation + uncoupling blunts the response to dobutamine/noradrenaline. Milrinone (PDE-3 inhibitor) bypasses the receptor — rationale for combination/independent inotropy.[6]
The depression is GLOBAL, not regional. Cytokines bathe the whole myocardium → diffuse hypokinesis ± dilatation. A regional wall motion abnormality in a septic patient is a red flag for concomitant ischaemia / takotsubo, not pure SICM.[4]

Diagnosis

Echocardiography — the cornerstone

Findings supporting SICM:

Reduced LV ejection fraction (EF) — classically <50%, often 30-40% in active SICM. May be profoundly depressed in severe cases.
LV dilatation — increased LVEDD/LVEDV; the heart dilates to preserve stroke volume via Starling's law (adaptive).
Global hypokinesis — diffuse, not regional. Regional wall motion abnormality → suspect ischaemia.
RV dysfunction — reduced TAPSE (<17 mm), RV dilatation, tricuspid annular plane systolic excursion, tricuspid regurgitation, paradoxical septal motion. Present in 30-50%.[17]
Diastolic dysfunction — impaired relaxation (Grade I-III). Assess E/A ratio, E/e' ratio (E/e' >14 suggests elevated LV filling pressure), left atrial volume index, deceleration time. Diastolic dysfunction is independently associated with mortality.
Hyperdynamic / normal EF in early sepsis — does NOT exclude SICM; diastolic dysfunction or reduced strain may be the only early clue.

Echocardiographic parameters in SICM — what to measure and why

Parameter	Abnormal in SICM	Cut-off / finding	Significance
LV ejection fraction (LVEF)	Systolic dysfunction	<50% (often 30-40%)	Hallmark; recoverable in 7-10 days
Global longitudinal strain (GLS)	Sub-endocardial dysfunction (precedes EF fall)	Less negative than −18% (−16% to −18%)	Most sensitive marker; detects dysfunction with "normal" EF
LVEDD / LVEDV	LV dilatation	LVEDD >5.8 cm (M, simplified)	Adaptive Starling compensation
RV function (TAPSE, FAC, S')	RV dysfunction	TAPSE <17 mm	Biventricular disease; worse prognosis
E/e' ratio	Diastolic dysfunction / ↑ filling pressure	>14 suggests elevated LV filling pressure	Independent mortality predictor
IVC size/collapsibility	Volume status & responsiveness	Collapsible (>50%) → fluid responsive	Guide fluid vs inotrope decision
Regional wall motion	Should be ABSENT in SICM	RWM abnormality → suspect ischaemia/takotsubo	Key differentiator

[1]

Global longitudinal strain (GLS) — the sensitive early marker

Cardiac biomarkers

Troponin (hs-cTnT/cTnI) — elevated in 50-80% of septic shock patients; reflects cytokine-mediated myocyte injury, microvascular dysfunction, type 2 MI and direct oxidative damage (not plaque rupture). A meta-analysis (Sheyin 2015) showed troponin elevation confers significantly higher mortality (OR ~2) in sepsis.[12] Use trends, not a single value, and interpret in context — do not reflexively coronary-angiogram an isolated troponin rise.
BNP / NT-proBNP — elevated in SICM from ventricular wall stress; correlates with the severity of dysfunction and prognosis. Rising BNP with falling EF suggests worsening SICM; falling BNP parallels recovery.[14] Useful to distinguish cardiogenic from septic pulmonary oedema and to follow response to therapy.

Cardiac MRI — for atypical or persistent cases

Imaging modalities in suspected SICM

Modality	Role	Strengths	Limitations
Bedside TTE / FOCUS	First-line, serial	Immediate, repeatable, no transport; assesses EF, RV, IVC, effusion	Operator-dependent; visual EF less precise
Comprehensive TTE + GLS	Definitive echo assessment	Speckle-tracking GLS detects subclinical dysfunction; diastolic assessment	Needs experienced sonographer/vendor
Transoesophageal echo (TOE)	If TTE poor windows / valvular query	High image quality; intraoperative	Semi-invasive; not first-line
Cardiac MRI	Persistent/atypical dysfunction	Tissue characterisation (oedema, LGE); excludes myocarditis/ischaemia	Transport of critically ill; not acute
Coronary angiography	If ischaemia suspected (regional WMA, type 1 MI)	Defines coronary anatomy; therapeutic (PCI)	Invasive; not for isolated troponin rise

[1]

Diagnostic workup of suspected sepsis-induced cardiomyopathy

Suspect — septic shock with new cardiac dysfunction, rising lactate despite resuscitation, hypoxaemia, oliguria, cool peripheries OR unexpectedly low SvO₂
Early bedside TTE (≤6 h) — EF, LV size, RV function (TAPSE), diastolic (E/e'), IVC, pericardial effusion, regional wall motion
Biomarkers — troponin (baseline + trend), BNP/NT-proBNP, lactate, venous/arterial blood gas
Compare to baseline — any prior echo, ECG, troponin (pre-existing cardiomyopathy vs new)
Classify haemodynamics — fluid-responsive vs not; warm (vasoplegic) vs cold (low output) shock phenotype
If EF depressed and fluid-resuscitated but still hypoperfused → add inotrope (dobutamine first; milrinone if RV dysfunction/vasoconstriction)
Serial echocardiography every 24-48 h — track EF/GLS recovery; daily biomarker trend
If EF NOT recovering by day 10-14 → cardiac MRI ± coronary angiography to exclude ischaemia, myocarditis, takotsubo, pre-existing cardiomyopathy

[1]

Diagnosis pearls — what the examiner wants to hear

Echo is the cornerstone, but normal EF does NOT exclude SICM. Diastolic dysfunction and reduced global longitudinal strain may be the only early signs. Always measure GLS if available — it is more sensitive than EF and a stronger prognostic marker.[4]
A regional wall motion abnormality is a red flag for ischaemia, not SICM. SICM causes global hypokinesis ± dilatation. Discrete, territory-based hypokinesis → coronary angiography to exclude type 1 MI/takotsubo.[5]
Always assess BOTH ventricles. RV dysfunction (TAPSE, RV FAC, S') is present in up to half and worsens prognosis, yet is the most commonly missed bedside finding.[17]
Troponin elevation predicts mortality (Sheyin meta-analysis OR ~2), but does not equal type 1 MI. Use trends; correlate with echo; do not reflexively cath lab a septic patient with an isolated troponin.[12]
BNP/NT-proBNP tracks SICM severity and recovery. Rising BNP + falling EF = worsening disease; falling BNP = recovery. Useful adjunct to serial echo.[14]
Cardiac MRI is the tie-breaker for non-recovering EF. Absent late gadolinium enhancement supports functional SICM; subendocardial LGE → ischaemia; mid-wall/subepicardial LGE + oedema → myocarditis.[15]
Hyperdynamic EF in early sepsis is the opposite phenotype and a pitfall. A "tight", hypercontractile LV with small cavity and low SVR is also abnormal in septic shock — do not be reassured by EF >70%.[6]

Differentiating SICM from pre-existing cardiomyopathy and mimics

Key differentiators:

History — any prior echo, heart failure admission, IHD, valve disease, cardiotoxic chemotherapy, familial cardiomyopathy. A normal prior EF strongly supports SICM.
ECG — Q waves, old infarct, persistent ST changes suggest chronic/pre-existing disease. Diffuse non-specific changes common in both sepsis and myocarditis.
Echo pattern — SICM: global hypokinesis ± dilatation, normal valve structure, little/no LVH. Pre-existing: regional WMA (post-MI), marked LVH (hypertensive/HFpEF), restrictive/hypertrophic phenotypes, valvular disease.
Wall motion — regional → ischaemia/takotsubo; global → SICM.
Takotsubo — apical ballooning with basal hyperkinesis, often triggered by sepsis; can coexist with SICM and is itself reversible.
Biomarker trajectory — SICM: troponin mild-moderate, rises then falls with recovery. Acute MI: steep rise, territory echo. Myocarditis: troponin often markedly elevated, ECG changes, viral prodrome.
Coronary angiography — the gold-standard discriminator when ischaemia is plausible (regional WMA, type 1 MI features).
Cardiac MRI — tissue characterisation to distinguish myocarditis (oedema + mid-wall/subepicardial LGE) from SICM (minimal LGE) and ischaemia (subendocardial LGE).[15]

SICM vs cardiogenic shock vs takotsubo vs myocarditis vs pre-existing cardiomyopathy

Feature	SICM	Cardiogenic shock (AMI)	Takotsubo	Acute myocarditis	Pre-existing cardiomyopathy
Context	Septic shock	Ischaemic event	Emotional/physical stress (incl. sepsis)	Viral prodrome	Chronic HF history
SVR	Low (vasoplegic, warm)	High (cold)	Variable	Variable	Variable
EF	Reduced, recoverable	Reduced, regional WMA	Reduced, apical ballooning	Reduced, global	Chronically reduced
Wall motion	Global hypokinesis	Regional (coronary)	Apical ballooning, basal hyperkinesis	Global, often patchy	Regional or global
LGE (MRI)	Minimal/absent	Subendocardial/transmural	Apical/mid-cavity oedema	Mid-wall/subepicardial + oedema	Variable (often established)
Troponin	Mild-moderate, trend	Marked, rise-fall	Moderate	Often markedly high	Variable
Reversibility	Yes, 7-10 days	Depends on revascularisation	Yes, days-weeks	Variable	Usually no
First treatment	Noradrenaline + treat sepsis + inotrope	Revascularise + MCS	Supportive, treat trigger	Immunosuppression (selected)	Guideline HF therapy

[1]

Differentiation pearls — high-stakes distinctions

The single most useful piece of information is a prior echocardiogram. A normal EF within the last 1-2 years in a patient now in septic shock with reduced EF is strong evidence for SICM (reversible). Absent baseline → assume SICM if global dysfunction, but stay alert to alternatives if recovery is delayed.[1]
Regional wall motion = ischaemia until proven otherwise. Territory-based hypokinesis does not fit cytokine-mediated global depression; pursue coronary angiography.[5]
Takotsubo can masquerade as SICM (and vice versa). Both are reversible and can be triggered by sepsis. The differentiator is the apical ballooning + basal hyperkinesis morphology of takotsubo vs the global, diffuse hypokinesis of SICM.[6]
Troponin magnitude is a clue, not a rule. Very high troponin with global dysfunction and a viral prodrome favours myocarditis; moderate troponin in fulminant sepsis favours SICM. But there is heavy overlap — use MRI when uncertain.[12][15]
A patient with known severe LV dysfunction who then gets sepsis does NOT have SICM — they have chronic cardiomyopathy decompensated by sepsis. The distinction matters for prognosis and for whether to expect recovery.[1]
Persistent EF depression beyond 10-14 days mandates reassessment. Recovery that does not occur on schedule is the strongest clue that the diagnosis is wrong — escalate to MRI ± angiography.[1]

Reversibility and natural history

Timeline:

Onset (Day 0-2): EF falls within hours-days of shock; troponin/BNP rise; LV dilates; RV dysfunction may appear.
Nadir (Day 2-4): maximal depression; inotrope requirement greatest; highest mortality risk.
Recovery (Day 4-10): EF climbs back towards baseline as cytokines clear and mitochondrial function recovers; inotropes wean; biomarkers fall.
Resolution (Day 7-10+): 60-80% of survivors regain a normal (or near-normal) EF. A minority (20-40%) have persistent dysfunction — usually pre-existing cardiomyopathy unmasked by sepsis, or (rarely) permanent sepsis-induced injury. [1]

Caveat: recovery presumes adequate source control and antimicrobial therapy. If the septic drive persists (undrained collection, resistant organism), SICM persists and may progress. [1]

Reversibility data — Parker/Parrillo 1990 and modern series

Parker/Parrillo (Ann Intern Med 1990): in survivors of septic shock, depressed EF recovered to normal within 7-10 days; non-survivors had a paradoxically higher early EF (less depression) — the so-called "reversal" finding, since explained by inability to mount the adaptive LV dilatation.[5]
Modern echo series: EF recovery in 60-80% of survivors by day 7-10; persistent LV dysfunction in 20-40%.
Diastolic dysfunction (E/e') recovery often lags systolic recovery by days — do not be alarmed by persistent diastolic impairment if EF is normalising.
GLS recovery lags EF recovery — follow GLS trends for completeness.

Reversibility pearls — what to expect and when to worry

Expect recovery by day 7-10 in survivors. If it is not happening, reassess — either the sepsis is uncontrolled or the diagnosis is wrong.[1]
The Parker "reversal" paradox is exam gold. Non-survivors had a higher early EF because they were too sick to mount adaptive LV dilatation; survivors' EF fell (dilated) then recovered. Do not over-read a "good" EF in fulminant septic shock.[5]
Diastolic recovery lags systolic recovery. Persisting high E/e' after EF normalises is expected and not, by itself, a sign of failure.[2]
RV dysfunction recovers alongside LV, but RV failure is a stronger independent mortality predictor. Persistent RV dysfunction at day 7 is a poor sign.[17]
The driver of mortality is the underlying sepsis, not the EF number. A patient can die of septic shock with a recovering EF. Do not equate EF normalisation with resolution of sepsis.[8]
Recovery is the rule, but a small subset develop persistent dysfunction. These are usually patients with unmasked pre-existing disease, dual pathology (myocarditis/takotsubo), or profound prolonged shock. Investigate, do not simply label "slow SICM".[1]

Management

Step 1 — Resuscitate the sepsis (Surviving Sepsis Campaign 2021)

Antibiotics within 1 hour of recognition; broad-spectrum, source-directed.
Source control as soon as practical (drainage, debridement, device removal).
Early crystalloid — at least 30 mL/kg in the first 3 h for septic shock with hypoperfusion, but titrated dynamically to dynamic fluid-responsiveness metrics. The 2021 SSC weakened the fixed 30 mL/kg recommendation precisely because of harm from injudicious fluid in non-responders.[11]

Step 2 — Assess fluid responsiveness BEFORE giving more fluid

Passive leg raise (PLR) — the best bedside test (sensitivity/specificity ~85%); starts at 45° semi-recumbent → flat + legs elevated 45° for 60-90 s; a ≥10% rise in cardiac output/stroke volume (or pulse pressure/variations) = responder. Monnet's meta-analysis confirms PLR outperforms static indices.[13]
IVC collapsibility (>50% collapse in spontaneously breathing; distensibility >18% in ventilated) — quick, qualitative.
Stroke volume variation / pulse pressure variation — in fully ventilated, deeply sedated patients with closed chest.
Fluid challenge — 250-500 mL bolus with real-time CO measurement.
Echocardiographic SV assessment (LVOT VTI) before/after PLR.

Decision: responder → give fluid (small aliquots, recheck). Non-responder or hypoperfusion persists after adequate fluid → move to vasopressors ± inotropes. [1]

Tests of fluid responsiveness in septic shock

Test	How performed	Threshold for "responder"	Pitfalls
Passive leg raise (PLR)	Semi-recumbent 45° → legs up 45°, trunk flat, 60-90 s	ΔSV or ΔCO ≥10%	Start from 45° (not flat); auto-transfuse ~300 mL
IVC collapsibility (spontaneous)	M-mode subxiphoid	>50% collapse	Unreliable if mechanically ventilated or high PEEP
IVC distensibility (ventilated)	M-mode	>18% distensibility	Needs fully controlled ventilation, closed chest
SVV / PPV	Arterial/pulse-contour	>12-13%	Only valid in deep sedation, controlled ventilation, regular rhythm
Mini fluid challenge	50-250 mL bolus + real-time CO/VTI	ΔSV ≥10%	Needs CO monitor/echo; transient

[1]

Step 3 — Vasopressors (noradrenaline first-line)

Target MAP ≥65 mmHg (lower acceptable if chronic HTN controlled; individualise).[11]

Noradrenaline (norepinephrine) FIRST-LINE — α-1 vasoconstriction restores SVR + modest β-1 inotropy. Even with SICM it is preferred: it improves coronary perfusion pressure and supports the depressed myocardium without the arrhythmia burden of dopamine.
Vasopressin (0.01-0.04 U/min) — add as second agent to reduce noradrenaline dose (catecholamine-sparing); fixed low dose. Not a first-line solo agent.
Adrenaline (epinephrine) — alternative/add-on; more arrhythmias, ↑lactate (β-2 glycolysis), but potent inotrope + vasoconstrictor.
Dopamine — AVOID unless specifically bradycardic shock. SOAP II (De Backer, NEJM 2010): dopamine vs noradrenaline showed no mortality difference overall but significantly more arrhythmias with dopamine (mostly atrial fibrillation), and a subgroup signal of worse outcome in cardiogenic shock.[9]

Step 4 — Inotropes (when low cardiac output persists)

Dobutamine — β-1 agonist (with some β-2). Increases contractility and CO, modest vasodilation (can drop SVR/MAP — usually co-administered with noradrenaline). First-line inotrope in SICM with low output. Start 2.5-5 µg/kg/min, titrate.
Milrinone — PDE-3 inhibitor; ↑cAMP independent of β-receptor (useful given β-desensitisation in sepsis); inotrope + lusitrope + vasodilator, including pulmonary vasodilation → preferred when RV dysfunction or pulmonary hypertension coexists. Longer half-life (~2.5 h) — harder to titrate acutely; can cause hypotension (often need noradrenaline concurrently).
Levosimendan — calcium sensitiser; improves contractility without rising intracellular calcium (theoretically less arrhythmia/O₂ demand). LeoPARDS trial (Antcliffe, ICM 2019) found NO benefit on SOFA-derived organ dysfunction or mortality in septic shock with biochemical cardiac dysfunction; not routinely recommended.[10]

Inotropes in sepsis-induced cardiomyopathy

Agent	Mechanism	Haemodynamic effect	Best use in SICM	Key cautions
Dobutamine	β-1 (±β-2) agonist	↑CO, ↓SVR (modest), ↑HR	First-line; LV low output	Tachyarrhythmia; ↑myocardial O₂ demand; can drop MAP
Milrinone	PDE-3 inhibitor → ↑cAMP	↑CO, ↓SVR + ↓PVR	RV dysfunction / pulmonary HTN; β-desensitised patient	Long t½; hypotension; often need noradrenaline
Levosimendan	Calcium sensitiser	↑CO, vasodilation	NOT routine (LeoPARDS negative)	Hypotension; cost; no outcome benefit
Adrenaline	α/β agonist	↑CO + ↑SVR (high dose)	Refactory shock with low CO	↑Lactate (β-2), arrhythmias, ↑O₂ demand
Dopamine	Dose-dependent D/α/β	Variable	Only if bradycardic shock	SOAP II: more arrhythmias; AVOID generally

[1]

Step 5 — Avoid excessive fluid (a recurring, lethal error)

Deresuscitate — once stable, achieve negative fluid balance with diuretics (furosemide) or RRT if needed.
Late shock = less fluid, more vasopressor/inotrope. The classic "give fluid, give more fluid" reflex kills in SICM.
Monitor cumulative fluid balance daily; target even-to-negative balance after the first 24-48 h.

Step 6 — Mechanical circulatory support (rare, refractory cases)

Haemodynamic management algorithm for SICM

Resuscitate sepsis — antibiotics <1 h, source control, initial 30 mL/kg crystalloid (titrate)
Assess volume status + fluid responsiveness — PLR, IVC, SVV/PPV, echo VTI. If responsive → 250-500 mL aliquots, reassess
Start vasopressor — noradrenaline first-line; target MAP ≥65; add vasopressin 0.03 U/min if escalating
Reassess perfusion — lactate trend, SvO₂, urine output, skin temp, echo EF/CO
If hypoperfusion persists + reduced EF/low CO → add dobutamine 2.5-5 µg/kg/min (titrate to CO/SvO₂ 65-70%); ensure adequate MAP with noradrenaline
If RV dysfunction / pulmonary HTN → add/switch to milrinone (with noradrenaline for MAP)
Avoid dopamine (SOAP II: more arrhythmias); do NOT use levosimendan routinely (LeoPARDS negative)
Stop fluids once euvolaemic — deresuscitate with diuretics; track cumulative balance
Serial echo + biomarkers — expect EF recovery by day 7-10; if not, reassess diagnosis
Refractory low output despite maximal therapy → MDT for short-term MCS (VA-ECMO/Impella) as bridge to recovery

[1]

Management pearls — what actually changes outcome

Source control is the definitive therapy for SICM. The heart recovers when the cytokine load clears — driven by drainage, debridement, device removal, and targeted antibiotics, not by inotropes. Never delay source control for investigations.[11]
Always test fluid responsiveness before more fluid or an inotrope. PLR is the best bedside test; giving dobutamine to a dry patient or fluid to a non-responder both worsen outcomes.[13]
Noradrenaline is first-line even when EF is reduced. It improves coronary perfusion pressure and supports the depressed myocardium with fewer arrhythmias than dopamine. The low SVR of septic shock needs correcting regardless of EF.[9]
Dobutamine drops MAP — co-administer with noradrenaline. β-2 vasodilation can cause precipitate hypotension in a vasoplegic patient; do not start dobutamine without a vasopressor running.[6]
Milrinone is the inotrope of choice when RV dysfunction coexists. Its pulmonary vasodilation reduces RV afterload, and its PDE-3 mechanism bypasses β-receptor desensitisation. Beware the long half-life and hypotension.[6]
Levosimendan does NOT improve outcomes in septic shock (LeoPARDS). Despite elegant mechanistic rationale (calcium sensitiser, less O₂ demand), the trial was negative — do not use routinely.[10]
Dopamine causes more arrhythmias than noradrenaline (SOAP II). Reserve it for the rare bradycardic septic shock patient.[9]
Fluid overload is a recurring, preventable killer in SICM. Late shock should be managed with less fluid and more vasopressor/inotrope; deresuscitate early. A flooded RV fails fast.[11][13]
Target SvO₂/ScvO₂ 65-70% as a perfusion goal once fluid-resuscitated. Low SvO₂ despite adequate MAP and volume = low CO = add inotrope; this is the physiological basis for dobutamine in SICM.[6]
Refractory SICM may need short-term MCS. VA-ECMO or Impella as a bridge-to-recovery is reasonable if the sepsis is treatable; outcome hinges on the underlying source, not the device.[6]

Clinical significance — does myocardial depression drive mortality?

Why SICM correlates with mortality:

A larger cytokine load produces both greater myocardial depression AND greater multi-organ failure — SICM flags the sicker patient.
SICM reduces the compensatory rise in cardiac output needed to meet the high septic oxygen demand, worsening tissue hypoxia and lactate.
RV dysfunction (a component of SICM) independently predicts mortality through hypoxaemia and low output.
Severe SICM drives escalating catecholamine use → arrhythmias, myocardial O₂ demand, microvascular insult. [1]

Why SICM itself is not usually the cause of death:

EF recovers in survivors — death from "SICM" alone is rare.
Most deaths are from multi-organ failure secondary to uncontrolled sepsis, with the recovering heart as a bystander.
The Parker "reversal" paradox: non-survivors had less early EF depression (could not dilate adaptively). [1]

Evidence base — landmark trials and meta-analyses

Parrillo/Parker 1990 (Ann Intern Med) — established the reversible, dilated, depressant-substance phenotype of human septic shock cardiomyopathy.[5]
Parrillo 1985 (J Clin Invest) — proved a circulating myocardial depressant substance in septic serum (in vitro myocyte depression).[3]
Kumar 1996 (J Exp Med) — TNF-α and IL-1β are the principal depressant cytokines (immunoneutralisation abolishes the effect).[7]
De Backer 2010 SOAP II (NEJM) — dopamine vs noradrenaline: no overall mortality difference but more arrhythmias with dopamine → noradrenaline first-line.[9]
Antcliffe 2019 LeoPARDS (Intensive Care Med) — levosimendan in septic shock with biochemical cardiac dysfunction: no benefit on organ dysfunction/mortality → not routine.[10]
Hasegawa 2023 (J Intensive Care Med) — systematic review and meta-analysis of SICM prevalence and prognosis: SICM common and associated with higher mortality (OR ~1.9).[8]
Monnet 2016 (Intensive Care Med) — passive leg raising meta-analysis: best bedside fluid-responsiveness test.[13]
Sheyin 2015 (Heart Lung) — troponin elevation in sepsis meta-analysis: prognostic (OR ~2 for mortality).[12]
Evans 2021 (Crit Care Med) — Surviving Sepsis Campaign guidelines: noradrenaline first-line, dopamine to be avoided, inotrope if low CO persisting after adequate fluid + vasopressor.[11]

Clinical-significance pearls — the mortality story

SICM = sicker patient. The depression reflects a larger inflammatory burden; mortality is higher because the sepsis is worse, not (usually) because the heart fails.[1][8]
EF recovery does not equal sepsis resolution. A patient can die with a normalising EF. Keep treating the source.[5]
RV dysfunction is the strongest cardiac mortality predictor in SICM. Biventricular disease carries the worst prognosis; assess RV at every echo.[17]
Troponin and BNP are prognostic biomarkers, not diagnostic gatekeepers. Rising troponin/BNP in septic shock = worse outcome — use them to risk-stratify and follow trends.[12][14]
Catecholamine burden is itself harmful. Escalating inotropes/vasopressors drive arrhythmias and O₂ demand; the goal is the lowest effective dose, achieved by source control + fluid optimisation.[6]
The Parker "reversal" paradox is the single highest-yield viva concept. Survivors' EF fell (adaptive dilatation) then recovered; non-survivors' EF stayed higher (could not dilate). A "good" EF in fulminant septic shock is not reassuring.[5]
Counsel families: the heart usually recovers. Setting the expectation that EF normalises within 7-10 days (if sepsis is controlled) is part of good prognostic communication — but pair it with the message that overall mortality is driven by the sepsis.[1]

Management red flags — errors that harm

Giving more fluid to a non-responder → pulmonary oedema, RV overload, intra-abdominal hypertension. Test responsiveness first.[13]
Starting dobutamine without a vasopressor → precipitate hypotension from β-2 vasodilation.[6]
Using dopamine first-line → more arrhythmias (SOAP II); reserve for bradycardic shock.[9]
Using levosimendan routinely → no outcome benefit (LeoPARDS); do not default to it.[10]
Attributing death to "cardiac failure" when EF is recovering → miss persistent/uncontrolled sepsis. Reassess the source.[1]
Failing to reassess diagnosis if EF does not recover by day 10-14 → miss myocarditis, ischaemia, takotsubo, pre-existing cardiomyopathy.[1][15]
Ignoring RV dysfunction → untreated RV failure drives hypoxaemia and death; assess TAPSE at every echo.[17]

References

[1]Hollenberg SM, Singer M Pathophysiology of sepsis-induced cardiomyopathy Nat Rev Cardiol, 2021.PMID 33473203
[2]Hunter JD, Doddi M Sepsis and the heart Br J Anaesth, 2010.PMID 19939836
[3]Parrillo JE, Burch C, Shelhamer JH, et al A circulating myocardial depressant substance in humans with septic shock. Septic shock patients with a reduced ejection fraction have a circulating factor that depresses in vitro myocardial cell performance J Clin Invest, 1985.PMID 4056039
[4]Sato R, Nasu M A review of sepsis-induced cardiomyopathy J Intensive Care, 2015.PMID 26566443
[5]Parrillo JE, Parker MM, Natanson C, et al Septic shock in humans. Advances in the understanding of pathogenesis, cardiovascular dysfunction, and therapy Ann Intern Med, 1990.PMID 2197912
[6]Kakihana Y, Ito T, Nakahara M, et al Sepsis-induced myocardial dysfunction: pathophysiology and management J Intensive Care, 2016.PMID 27011791
[7]Kumar A, Thota V, Dee L, et al Tumor necrosis factor alpha and interleukin 1beta are responsible for in vitro myocardial cell depression induced by human septic shock serum J Exp Med, 1996.PMID 8642298
[8]Hasegawa D, Ishisaka Y, Sato R, et al Prevalence and Prognosis of Sepsis-Induced Cardiomyopathy: A Systematic Review and Meta-Analysis J Intensive Care Med, 2023.PMID 37272081
[9]De Backer D, Biston P, Devriendt J, et al (SOAP II) Comparison of dopamine and norepinephrine in the treatment of shock N Engl J Med, 2010.PMID 20200382
[10]Antcliffe DB, Santhakumaran S, Whitehouse T, et al (LeoPARDS) Levosimendan in septic shock in patients with biochemical evidence of cardiac dysfunction: a subgroup analysis of the LeoPARDS randomised trial Intensive Care Med, 2019.PMID 31428804
[11]Evans L, Rhodes A, Alhazzani W, et al Executive Summary: Surviving Sepsis Campaign: International Guidelines for the Management of Sepsis and Septic Shock 2021 Crit Care Med, 2021.PMID 34643578
[12]Sheyin O, Davies O, Duan W, Perez X The prognostic significance of troponin elevation in patients with sepsis: a meta-analysis Heart Lung, 2015.PMID 25453390
[13]Monnet X, Marik P, Teboul JL Passive leg raising for predicting fluid responsiveness: a systematic review and meta-analysis Intensive Care Med, 2016.PMID 26825952
[14]Pandompatam G, Kashani K The role of natriuretic peptides in the management, outcomes and prognosis of sepsis and septic shock Rev Bras Ter Intensiva, 2019.PMID 31618357
[15]Muehlberg F, Blaszczyk E, Besse L, et al Characterization of critically ill patients with septic shock and sepsis-associated cardiomyopathy using cardiovascular MRI ESC Heart Fail, 2022.PMID 35587684
[16]Hare JM, Colucci WS Role of nitric oxide in the regulation of myocardial function Prog Cardiovasc Dis, 1995.PMID 7568904
[17]Parker MM, McCarthy KE, Ognibene FP, et al Right ventricular dysfunction and dilatation, similar to left ventricular changes, characterize the cardiac depression of septic shock in humans Chest, 1990.PMID 2295231

Your progress

Exam practice

SAQ — Septic cardiomyopathy with EF 25 percent and ongoing hypoperfusion

SAQ — Sepsis-induced cardiomyopathy versus pre-existing cardiomyopathy

Clinical pearls

Red flags

Prognosis

Outcomes of sepsis-induced cardiomyopathy (Parker/Parrillo 1990, Hasegawa 2023 meta-analysis)

Pathophysiology — deep dive

1. Circulating myocardial depressant substances

2. Nitric oxide (NO) pathway

3. Mitochondrial dysfunction

4. Beta-adrenergic receptor downregulation / desensitisation

5. Coronary microcirculatory dysfunction

Diagnosis

Echocardiography — the cornerstone

Global longitudinal strain (GLS) — the sensitive early marker

Cardiac biomarkers

Cardiac MRI — for atypical or persistent cases

Differentiating SICM from pre-existing cardiomyopathy and mimics

Reversibility and natural history

Reversibility data — Parker/Parrillo 1990 and modern series

Management

Step 1 — Resuscitate the sepsis (Surviving Sepsis Campaign 2021)

Step 2 — Assess fluid responsiveness BEFORE giving more fluid

Step 3 — Vasopressors (noradrenaline first-line)

Step 4 — Inotropes (when low cardiac output persists)

Step 5 — Avoid excessive fluid (a recurring, lethal error)

Step 6 — Mechanical circulatory support (rare, refractory cases)

Clinical significance — does myocardial depression drive mortality?

Evidence base — landmark trials and meta-analyses

References

Your progress

Exam practice

SAQ — Septic cardiomyopathy with EF 25 percent and ongoing hypoperfusion

SAQ — Sepsis-induced cardiomyopathy versus pre-existing cardiomyopathy

Clinical pearls

Red flags

Prognosis

Outcomes of sepsis-induced cardiomyopathy (Parker/Parrillo 1990, Hasegawa 2023 meta-analysis)

Pathophysiology — deep dive

1. Circulating myocardial depressant substances

2. Nitric oxide (NO) pathway

3. Mitochondrial dysfunction

4. Beta-adrenergic receptor downregulation / desensitisation

5. Coronary microcirculatory dysfunction

Diagnosis

Echocardiography — the cornerstone

Global longitudinal strain (GLS) — the sensitive early marker

Cardiac biomarkers

Cardiac MRI — for atypical or persistent cases

Differentiating SICM from pre-existing cardiomyopathy and mimics

Reversibility and natural history

Reversibility data — Parker/Parrillo 1990 and modern series

Management

Step 1 — Resuscitate the sepsis (Surviving Sepsis Campaign 2021)

Step 2 — Assess fluid responsiveness BEFORE giving more fluid

Step 3 — Vasopressors (noradrenaline first-line)

Step 4 — Inotropes (when low cardiac output persists)

Step 5 — Avoid excessive fluid (a recurring, lethal error)

Step 6 — Mechanical circulatory support (rare, refractory cases)

Clinical significance — does myocardial depression drive mortality?

Evidence base — landmark trials and meta-analyses

References