familial hypertrophic cardiomyopathy
fa·mil·i·al hy·per·tro·phic car·di·o·my·op·a·thy
[MIM*192600]hypertrophic cardiomyopathy
A common (1:500) condition which causes a range of mild to severe clinical and pathologic changes, which are either symmetrical (concentric) or asymmetrical (eccentric hypertrophy), with disproportionate thickening beneath the mitral valve, seen without other cardiac disease. Half are congenital with autosomal dominant patterns of inheritance—e.g., MIM 192600, MIM 160760. Obstruction is associated with reduced venous return.Clinical findings, young patients
Range from asymptomatic to diastolic dysfunction, dyspnea, fatigue, anginal pain, syncope, an increased risk of severe obstruction, congestive heart failure, sudden death simulating acute myocardial infarction.
Clinical findings, older patients
Shortness of breath, anginal pain, syncope.
EKG Increased
QRS complexes, T-wave inversion, Q waves in inferior and left-precordial leads—which translate into asymmetric hypertrophy of the septum (usually of left side), systolic anterior movement of mitral valve, and midsystolic closure of aortic valve.
Adverse associations
Ethanol in patients with HC increases systolic blood pressure, and the pressure gradient across left ventricular outflow tract.
Management
• Symptomatic—i.e., relief of dyspnoea or chest pain.
• Drugs—beta-adrenergics are effective short-term, calcium channel blockers (which increase diastolic ventricular filling) may be effective long-term.
• Surgery—recalcitrant cases may need a transaortic ventricular septal myotomy-myectomy.