Molecular, Cellular, and Functional Characterization of Myocardial Regions in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a heterogeneous disease. Although regional functional heterogeneity in HCM is well-known, cellular and molecular regional heterogeneity in human HCM remain unrecognized. We evaluated the molecular and histological heterogeneity as well as mitochondrial function in HCM and their relation to functional heterogeneity in 16 left ventricular segments from a patient with HCM with normal ejection fraction who underwent heart transplantation for advanced heart failure.The patient was a 61-year-old man who had a long-standing history of HCM with asymmetrical septal hypertrophy and maximum wall thickness of 26 mm. He underwent myectomy because of severe dyspnea and left ventricular outflow tract dynamic obstruction but was in New York Heart Association functional class IV heart failure despite successful surgery. He received an implantable cardioverter-defibrillator because of risk factors for sudden cardiac death. There was no evidence of epicardial coronary artery disease by angiography. The patient underwent cardiac transplantation because of persistent symptoms, …