Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease (1/500 to 1/1000) and is caused by mutations in one or more of 12 genes encoding protein components of the cardiac sarco- mere [1]. The phenotypic features of HCM may frst develop at any age, from infancy to adulthood, and are characterized by asymmetric left ventricular (LV) hypertrophy and a nondilated LV cavity [2–5]. Systolic function is preserved in most patients, and a dynamic LV outfow obstruction due to systolic anterior motion of the mitral valve is present under basal conditions in 20% to 25% of patients [2–5]. The diagnosis is tradi- tionally based on the echocardiographic demonstration of increased LV wall thickness in the absence of other cardiovascular diseases capable of producing a similar magnitude of hypertrophy [2–4]. Magnetic resonance is particularly useful for establishing the diagnosis in patients with wall thickening confned to segments not clearly visualized by the ultrasounds, such as the lateral free wall or the apical portion of the left ventricle [6,7]. However, thickening of the LV wall resembling HCM may be present in other genetic disorders, including Risk Stratification and Prevention Risk Stratification and Prevention of Sudden Death in Hypertrophic of Sudden Death in Hypertrophic Cardiomyopathy Cardiomyopathy Camillo Autore, MD Giovanni Quarta, MD Paolo Spirito, MD Corresponding author Paolo Spirito, MD Divisione di Cardiologia, Ente Ospedaliero Ospedali Galliera, Via Volta 8, Genoa 16128, Italy E-mail: paolo.spirito@galliera.it Current Treatment Options in Cardiovascular Medicine 2007, 9:431–435 Current Medicine Group LLC ISSN 1092-8464 Copyright © 2007 by Current Medicine Group LLC Opinion statement Sudden cardiac death is the most devastating manifestation of hypertrophic cardio- myopathy (HCM) and often occurs in young and previously asymptomatic patients. Therefore, risk stratification for sudden death has a major role in the management of HCM and has acquired even greater relevance since the implantable cardioverter- defibrillator (ICD) has proved to be highly effective in preventing sudden death in this disease. The ICD is definitely indicated for secondary prevention of sudden death in patients with HCM who have survived a cardiac arrest with documented ventricular fibrillation, or experienced one or more episodes of sustained ventricu- lar tachycardia. However, uncertainties persist regarding the precise selection of pa- tients for primary prophylactic ICD implantation. A number of risk markers are used to assess the magnitude of risk, including family history of premature sudden death; extreme left ventricular (LV) hypertrophy (> 30 mm) in young patients; nonsustained ventricular tachycardia on Holter electrocardiographic recording; unexplained (not neurally mediated) syncope, particularly in young patients; and blood pressure decrease or inadequate increase during upright exercise. Multiple risk factors con- vey a definite increase in risk. However, a single risk factor such as family history of multiple sudden deaths, massive LV hypertrophy in a young patient, or frequent and/or prolonged runs of nonsustained ventricular tachycardia on Holter, may also justify consideration of a prophylactic ICD. Introduction