Arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) has evolved from postmortem pathology at to a diagnosable clinical condition, and holds promise for definitive genetic diagnosis. Its prevalence is between 1/1,000 and 1/5,000, with 10% of deaths occurring before age 19 and 50% before age 35. When analyzed against age-specific norms, the electrocardiography (ECG) and signal-averaged ECG (SAECG) have moderate sensitivity for ARVC. Endomyocardial biopsy in young individuals with ARVC demonstrates fibrosis more frequently than fatty infiltration, and is convincing for the diagnosis in approximately 1/3 (often in patients who would not otherwise be diagnosed), but has a recognized complication rate of 2%. Newer technologies of magnetic resonance imaging and voltage mapping hold promise but require further assessment in young individuals suspected to have ARVC. Genetic diagnosis of one of several desmosomal mutations is positive in an approximately 50% of suspected patients, and may provide clues to the pathophysiology of the disease. Serial studies of myocardial function, ambulatory electrocardiography, and SAECG parameters may be useful in risk stratification of identified patients, although their applicability to genetically identified asymptomatic individuals has not been studied.