MCQ: Dilated Cardiomyopathy | Management

Correct answer: B. Milrinone infusion

This child has acute decompensated heart failure with cardiogenic shock due to severe LV systolic dysfunction. The key findings are EF 20%, hypotension, prolonged CRT, weak pulses, lethargy, tachycardia, pulmonary congestion, and hepatomegaly.

The important clue is that a small cautious fluid bolus has already been given, but the child remains hypotensive with poor perfusion and has not developed worsening pulmonary congestion. This suggests that additional fluid is unlikely to correct the problem and that the child needs inotropic support.

Why B is correct: Milrinone infusion

Milrinone is a phosphodiesterase-3 (PDE-3) inhibitor that produces:

• Positive inotropy → improves myocardial contractility
• Systemic vasodilation → reduces LV afterload
• Pulmonary vasodilation → can reduce pulmonary vascular resistance

In this child, the major problem is severe myocardial pump failure, rather than inadequate circulating volume.

The clinical sequence is important:

Severe LV dysfunction → cardiogenic shock → cautious fluid challenge → persistent hypotension/poor perfusion → inotropic support

Milrinone can therefore be considered when there is significant ventricular dysfunction with low cardiac output, particularly when afterload reduction is also desirable.

Because the child is markedly hypotensive (68/40 mmHg), however, this would require intensive-care monitoring. In profound hypotension, an agent with stronger vasopressor activity may also be required depending on the clinical situation; the question’s options make milrinone the best answer.

Why the other options are wrong

A. Furosemide bolus — Incorrect

Furosemide is useful for fluid overload and pulmonary/systemic congestion in heart failure.

This child certainly has congestion:

• Bilateral crepitations
• Hepatomegaly
• Cardiomegaly
• Pulmonary vascular congestion

However, the immediate life-threatening problem is cardiogenic shock with severe hypotension and poor systemic perfusion.

A diuretic does not directly improve myocardial contractility or cardiac output and can further reduce intravascular volume and worsen hypotension if used aggressively at this stage.

Therefore, inotropic support is the priority.

C. Prostaglandin infusion — Incorrect

Prostaglandin E1 is indicated when a neonate has a suspected duct-dependent congenital heart lesion.

This child is 18 months old, and echocardiography demonstrates a structurally normal heart apart from severe LV systolic dysfunction.

There is therefore no indication for maintaining ductal patency.

D. Repeat saline bolus — Incorrect

This is an important distractor.

The child has already received a cautious 5 mL/kg saline bolus and remains hypotensive.

Although fluid resuscitation may be appropriate when hypovolemia is suspected, this child has strong evidence of cardiogenic shock:

• EF 20%
• Dilated LV
• Cardiomegaly
• Gallop rhythm
• Pulmonary congestion
• Hepatomegaly
• Weak pulses

Giving repeated fluid boluses to a child with severe LV failure can increase pulmonary venous congestion and worsen pulmonary edema.

The fact that there is no worsening of crepitations after the initial small bolus does not mean that repeated large-volume fluid administration is appropriate.

E. Synchronized cardioversion — Incorrect

Cardioversion is indicated for unstable tachyarrhythmias, particularly when the tachycardia itself is responsible for hemodynamic compromise.

Although the heart rate is very high at 190/min, the clinical picture and echocardiography point toward severe ventricular pump failure rather than a primary tachyarrhythmia.

The presence of a dilated LV with EF 20% and global heart-failure findings indicates that myocardial dysfunction is the underlying problem.

Therefore, cardioversion is not the appropriate next step based on the information provided.

High-yield exam clue

This is a classic cardiogenic shock pattern:

Hypotension + weak pulses + prolonged CRT + severe LV dysfunction + pulmonary congestion                    

Reference: 

Kliegman RM, St. Geme JW III, Blum NJ, Shah SS, Tasker RC, Wilson KM, editors. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia: Elsevier; 2024.

If you find it useful this then solve another MCQ on management of dilated cardiomyopathy.