Hypertrophic cardiomyopathy evolving into a hypokinetic and dilated left ventricle: coronary embolization as a probable pathogenetic mechanism.

A long-term follow-up (9 years) in a patient with hypertrophic cardiomyopathy revealed an evolution to a hypokinetic and dilated left ventricle. The patient underwent heart transplantation, and therefore the native heart was available for morphologic studies. Gross and microscopic stigmata of hypertrophic cardiomyopathy were present, as well as evidence of left ventricular dilatation. Multiple myocardial scars in both ventricles indicated past ischemic episodes, most probably due to coronary embolization from left ventricular mural thrombi. Other possible pathogenetic mechanisms for the progression of hypertrophic cardiomyopathy to a dilated one are discussed.