Infantile hypertrophic cardiomyopathy masquerading as cardiac tamponade: A case report.

Hypertrophic cardiomyopathy in infancy often follows a rapidly progressive clinical course, with many cases becoming fulminant and fatal. We reported a case of a 4-month-old infant with worsening breathlessness. While admitted, she was in severe respiratory distress and appeared drowsy. We also noted indiscernible heart sounds from physical examination and cardiomegaly with a globular cardiac silhouette from chest X-ray. Considering her distressing clinical presentation, we suspected cardiac tamponade and performed an emergent transthoracic echocardiography to confirm our suspicion. Echocardiogram, however, demonstrated only mild pericardial effusion-insufficient to explain her symptoms. Moreover, we found exceedingly thick myocardium consistent with hypertrophic cardiomyopathy, so we initially focused our treatment strategy on congestion relief.