Pathophysiology
Interventricular septal hypertrophy
Hx
More common in African Americans
Autosomal dominant inheritance
Sx
Syncope (possibly multifactorial)
May be due to
Outflow obstruction
Arrhythmia
Ischemia
Ventricular baroreceptor response that inappropriately causes vasodilation
Dyspnea
Chest pain
PE
Carotid pulse with dual upstroke occurs from midsystolic obstruction that develops as the heart contracts
Crescendo-decrescendo systolic murmur along the L sternal border with strong apical impulse without carotid radiation
Valsalva enhances the murmur as preload decreases since this lessens the size of the ventricular cavity and causes increase outflow obstruction
