Our Patient - HOCM

The diagnosis of hypertrophic obstructive cardiomyopathy is suggested by the patient's history of a murmur in childhood and a family history of sudden death. Exertional dyspnea as well as the patient's episode of syncope are evidence that the condition is severe.

His physical examination demonstrated a bifid carotid arterial pulse with brisk peripheral pulses, a nearly diagnostic triple apical impulse, consisting of a presystolic component followed by a double systolic component, paradoxic splitting of the second heart sound, a mid systolic crescendo-decrescendo outflow ejection murmur, the murmur of mitral regurgitation due to mitral valve apparatus dysfunction and third and fourth heart sounds due to reduced left ventricular compliance.

The etiology of hypertrophic cardiomyopathy is related to a genetic mutation. It often occurs in several first degree relatives, reflecting an autosomal dominant inheritance pattern. A mutation in one of the multiple genes encoding cardiac muscle sarcomere protein is responsible for this disorder.

Hypertrophic cardiomyopathy may also occur without left ventricular outflow obstruction and the symptoms may vary. These patients may be entirely asymptomatic or present with exertional angina, syncope or dyspnea. These symptoms are due to abnormal muscle hypertrophy and diastolic dysfunction, rather than obstruction. Ventricular arrhythmias also contribute to syncopal spells and the predisposition to early sudden cardiac death.

The physical findings in hypertrophic cardiomyopathy without left ventricular outflow tract obstruction may also vary. The carotid arterial and peripheral pulses may be brisk and hyperkinetic, the apical impulse may be sustained and include a presystolic component and auscultation at the apex may reveal a fourth heart sound.