Heart failure in infants and children — structured clinical encounter

Station brief (candidate)

You are the paediatric registrar in the emergency department. A six-week-old term infant presents with a three-week history of worsening tachypnoea, taking 40 minutes to finish 60 mL of feeds while sweating, and crossing two weight centiles downward. On examination there is a pansystolic murmur at the lower left sternal border, an apical mid-diastolic murmur, a hyperactive precordium, and hepatomegaly with the liver edge 3 cm below the costal margin. Oxygen saturations are 98 percent in air. The team asks you to establish the diagnosis and immediate management, then proceed to the echocardiogram, the closure plan, and the family counselling. You have 12 minutes with the team and 5 minutes for examiner discussion. [3]

Information available on request

• Term infant, six weeks old, previously well; pregnancy and delivery uncomplicated. [3]
• Three-week history of worsening tachypnoea, prolonged sweaty feeds, crossing two weight centiles downward. [3]
• Examination: pansystolic murmur at lower left sternal border, apical mid-diastolic murmur, hyperactive precordium, hepatomegaly; saturations 98 percent in air; femoral pulses present and symmetric. [5]
• Chest radiograph (on request): cardiomegaly with pulmonary plethora. [3]
• Echocardiogram (on request): a perimembranous ventricular septal defect with a Qp:Qs of 2.4, left atrial and left ventricular dilation, and a pulmonary artery pressure estimate at the upper limit of normal; aortic valve normal. [4]

Tasks

1. Give the diagnosis and explain why it has presented now, at six weeks, rather than at birth. Grade the severity. [3] [5]
2. Outline your immediate medical management with the specific drug doses you would use as a bridge, and explain your approach to oxygen. [6]
3. State the definitive management and its timing. [4]
4. Discuss the role of a beta-blocker in this infant, citing the paediatric evidence. [7]
5. Counsel the parents on the immediate outlook and the principle that guides the plan. [6]

Marking anchors

Must-hit

• Diagnoses heart failure from pulmonary overcirculation due to a moderate-to-large ventricular septal defect, presenting at four to eight weeks as the pulmonary vascular resistance falls; grades it modified Ross class III; correctly identifies the apical mid-diastolic rumble as the sign of a large shunt through increased mitral inflow. [3] [5]
• Starts a medical bridge with a loop diuretic (furosemide 1 to 2 mg/kg/day), an ACE inhibitor (enalapril or captopril) and increased caloric density of feeds; uses oxygen cautiously with the correct physiological rationale that oxygen is a pulmonary vasodilator that can increase the left-to-right shunt and worsen the overcirculation. [6]
• Refers for closure within the first year (surgical patch or transcatheter device) and identifies the principle that most childhood heart failure is surgically curable because the cause is structural. [4]

Merit

• Names the Shaddy carvedilol randomised controlled trial and explains that it found no overall benefit in children, which is why beta-blockade is selective rather than routine, demonstrating the full evidence base. [7]

Fail

• Administers indiscriminate high-flow oxygen without recognising that it lowers pulmonary resistance and can worsen the overcirculation, or delays echocardiography and referral on the grounds that the infant is "not yet sick enough". [3]
• Counsels the family that the outlook is poor or that the child will need lifelong heart-failure medication, against the reality that closure is curative. [6]