title: Hypertrophic cardiomyopathy in the adolescent.
abstract: Hypertrophic cardiomyopathy is the more accurate term for the condition also known as idiopathic hypertrophic subaortic stenosis, asymmetric septal hypertrophy or hypertrophic obstructive cardiomyopathy. Although an uncommon condition in the adolescent, its importance lies in the fact that it is hereditary, sometimes difficult to diagnose clinically, and may be associated with sudden death - especially during or after exertion. All patients with a systolic murmur at the left sternal border should be made to stand, squat and perform a Valsalva maneuver while being auscultated. Since hypertrophic cardiomyopathy is associated with a dynamic intraventricular gradient, the murmur will change in character and intensity during these maneuvers. An electrocardiogram and echocardiogram is indicated if there is any suspicion of the diagnosis. Patients with hypertrophic cardiomyopathy should be prohibited from participating in competitive sports or performing strenuous activities even in the absence of a significant intracavitary gradient. They should be placed on high-dose beta-blockers and followed closely. Follow-up should include the use of Holter monitoring to exclude the presence of arrhythmias. Supraventricular or ventricular arrhythmias should be treated aggressively since they may be associated with sudden death. Family members or first-degree relatives should be screened by echocardiography for the condition and the patient informed of the genetic nature of the disease. The condition needs to be differentiated from the 'athlete's heart' which may present with a murmur and electrocardiographic and echocardiographic evidence of left ventricular hypertrophy, since the latter condition is considered physiologic and not an indication to discontinue an athlete's activities.
mesh_terms: D000293:Adolescent; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D003645:Death, Sudden / Q000209:etiology; D005260:Female; D006334:Heart Function Tests; D006801:Humans; D008297:Male; D013177:Sports