Transmural myocardial infarction in hypertrophic cardiomyopathy: a cause of conversion from left ventricular asymmetry to symmetry and from normal-sized to dilated left ventricular cavity.

Transmural myocardial infarction in the absence of epicardial coronary arterial narrowing is fairly common at necropsy in patients with hypertrophic cardiomyopathy. Although difficult to diagnose clinically in patients with hypertrophic cardiomyopathy, acute myocardial infarction occasionally has a typical presentation, as in the patient presented in this report. More often, however, transmural acute myocardial infarction in patients with hypertrophic cardiomyopathy is not associated with classic signs and symptoms, but leads to production of, or worsening of, congestive cardiac failure which thereafter usually rapidly progresses. Thus, transmural myocardial infarction is a major complication of hypertrophic cardiomyopathy.