Sudden death and hypertrophic cardiomyopathy: a review.

Hypertrophic cardiomyopathy is a genetic disease that affects the cardiac sarcomere, resulting in myocardial hypertrophy and disarray. Affected patients have a predisposition for malignant ventricular tachyarrhythmias and, consequently, sudden cardiac death. With the availability of therapeutic measures that prevent sudden death, the identification of high-risk patients is now of greater importance. Clinical risk factors for sudden death (ie, age, syncope, family history of sudden cardiac death, cardiac arrest survivor, nonsustained ventricular tachycardia and abnormal blood pressure response to exercise) have been identified. The clinical electrophysiological study is of limited use for stratifying these patients. More recently, increased attention has been given to the degree of echocardiographically documented left ventricular hypertrophy and prognostically significant genetic mutations. Once a high-risk patient is identified, prophylactic treatment is warranted. For this purpose, amiodarone has been supplanted by the implantable cardioverter-defibrillator. Implantable cardioverter-defibrillator treatment appears to reduce the risk of sudden cardiac death in both primary and secondary prevention settings. Thus, tools are now available to identify and treat high-risk patients with hypertrophic cardiomyopathy.