Asymmetric septal hypertrophy presenting with cardiogenic shock, complete heart block, and septal infarction despite...

A 37-year-old man, brought in following a syncopal episode, was found to be in cardiogenic shock with a complete infranodal heart block. A temporary transvenous pacemaker and an intra-aortic balloon pump were inserted emergently. Cardiac catheterization revealed a high left ventricular end-diastolic pressure but normal coronary vasculature. An echocardiogram demonstrated a hyperdynamic left ventricle, severe hypokinesis of the septum, and asymmetric septal hypertrophy. An endomyocardial biopsy showed myofibril hypertrophy and disarray. The patient required implantation of a permanent pacemaker for full recovery. Although arrhythmias are common in asymmetric septal hypertrophy, complete atrioventricular block is rare but can cause syncope and cardiogenic shock. This is the first case, reported in the literature, of asymmetric septal hypertrophy in which the patient presented with cardiogenic shock and complete heart block secondary to a septal infarction, despite normal coronaries, and in whom a myocardial biopsy was performed. The case report is followed by a review of the literature on hypertrophic cardiomyopathy associated with complete heart block.