Postural orthostatic tachycardia syndrome — structured clinical encounter

Candidate brief (5 minutes to read)

You are the general paediatrics registrar in clinic. This 15-year-old girl has a four-month history of daily, posture-driven symptoms that meet the standing-test criteria for postural orthostatic tachycardia syndrome. Your tasks are to confirm the diagnosis, exclude the cardiac causes, agree a management plan with the family, and explain why this is not the same as a fainting athletic boy with a family history of sudden death. [1]

Station tasks

Task 1 — Confirm the diagnosis and exclude cardiac syncope

Must-hit. State that this meets POTS criteria: chronic (≥3 months) daily orthostatic symptoms provoked by standing and eased by lying down; a heart-rate rise of 48 bpm (76 → 124) on the 10-minute stand, exceeding the ≥40 bpm adolescent threshold, without an orthostatic blood-pressure fall. Confirm that the cardiac red-flag screen is negative (no exertional, supine or warning-free collapse; no chest pain; no family history of sudden death) and that a 12-lead ECG has been obtained and read. [1] [3]

Probe. What if the blood pressure had fallen by 24/12 mmHg on standing? Answer. That would be orthostatic hypotension, not POTS — the blood-pressure response is the discriminating feature, which is why it must be measured throughout the stand test. [1]

Task 2 — Build the management plan

Must-hit. Lead with education, validation and reassurance (POTS is real and treatable), a symptom and standing diary, and a school plan (late starts, movement and water breaks, graded return). Then hydration and salt (around 2–3 L fluid, titrated sodium chloride; avoid excess salt in hypertension or renal disease). Then counter-pressure manoeuvres and compression garments. Then a structured recumbent or sub-threshold exercise programme to reverse the deconditioning spiral — the most evidence-based component. Reserve phenotype-guided pharmacotherapy (midodrine, fludrocortisone, beta-blocker, ivabradine) for insufficient response. Treat sleep, mood and school return in parallel and set an expectation of improvement over months. [5] [10]

Probe. Which phenotype would push you toward ivabradine? Answer. A hyperadrenergic picture — palpitations, tremor, anxiety, sometimes a rising blood pressure on standing — supported by a randomised trial of ivabradine in hyperadrenergic adults. [10]

Task 3 — Communicate with the family

Must-hit. Explain in plain language: the body is not returning blood from the legs efficiently on standing, so the heart races to keep the blood pressure up, and that produces the daily symptoms; it is not a heart defect, not epilepsy, and not anxiety, though anxiety and low mood often travel with it. Name the deconditioning spiral and the plan to reverse it, agree a concrete school-return plan, and safety-net the red flags that should bring them back (exertional collapse, chest pain, palpitations at rest, a family event). [3] [2]

Task 4 — Contrast with the cardiac trap

Must-hit. Contrast this case with a 14-year-old boy who collapses sprinting the 400 metres with no prodrome and a father who died suddenly at 34. That is cardiac syncope until proven otherwise — hypertrophic cardiomyopathy, long-QT, CPVT, arrhythmogenic cardiomyopathy — and demands sport restriction, an ECG, echocardiography, monitoring, exercise testing and family screening. POTS is a chronic orthostatic pattern and is never the label for an exertional collapse. [3] [1]

Examiner checklist

• Correctly applies the ≥40 bpm / ≥120 bpm adolescent threshold and the no-orthostatic-hypotension rule [1]
• Obtains and reads an ECG; runs a negative cardiac red-flag screen [3]
• Distinguishes POTS from orthostatic hypotension and vasovagal syncope using the standing-test pattern [1]
• Builds the stepwise ladder with reconditioning as the centrepiece [5] [10]
• Communicates the diagnosis, the deconditioning spiral, the school plan and the safety-net in plain language [2]
• Recognises the exertional-collapse trap and does not mislabel it as POTS [3]