arrhythmogenic right ventricular cardiomyopathy
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arrhythmogenic right ventricular cardiomyopathyA non-ischaemic right ventricular cardiomyopathy, which is the single most common cause of sudden cardiac death attributable to heredity. It presents in children and young (male) adults as syncope due to ventricular arrhythmia or as sudden cardiac death in young athletes.
Clinical findings Strong familial tendency; asymptomatic, 10%; recurrent ventricular tachycardia with left bundle branch pattern, 45%; congestive heart failure, 25%; heart murmur, 10%; sudden death, 5%. Usually presents with palpitations, syncope, symptomatic arrhythmias, or sudden death during exercise in a young person.
Diagnosis EKG T wave inversion in V1–V3; 2-D and M mode echocardiography may be useful.
Management Beta-blockers, ablation with 90% initial success rate but 60% recurrence, implantable cardioverter-defibrillators, treatment of heart failure when it develops.
cardiomyopathy(kard?e-o-mi-op'a-the) [ cardio- + myopathy],
arrhythmogenic right ventricular cardiomyopathyAbbreviation: ARVC
Arrhythmogenic right ventricular dysplasia.
constrictive cardiomyopathyRestrictive cardiomyopathy.
eosinophilic cardiomyopathyLöffler endocarditis.
hypertrophic cardiomyopathyAbbreviation: HCM
Symptoms and Signs
Although patients may be asymptomatic for many years, they commonly report shortness of breath (particularly on exertion), fatigue, atypical chest pain (at rest and after meals), orthopnea, dizziness, and other symptoms of congestive heart failure after the heart muscle markedly enlarges. An S4 and a harsh crescendo-decrescendo systolic murmur, best heard at the left lower sternal border, may be present. Ventricular arrhythmias are common and may result in palpitations, syncope, or sudden death.
Drug therapies include beta blocking and calcium channel blocking drugs (such as verapamil) to slow heart rate, control arrhythmias, and reduce myocardial oxygen demand. Anticoagulants and antiarrhythmic agents are also occasionally used. For patients with marked enlargement of the ventricular septum and high outflow tract pressure gradients (> 50 mm Hg), surgical removal of the enlarged muscle or ablation often produces favorable improvements in exercise tolerance and breathing.
Strenuous physical exercise should be discouraged because it may produce breathlessness, presyncope, or frank loss of consciousness. If applicable, the patient should be encouraged to lose weight, stop smoking, and limit alcohol intake. An implanted cardioverter/defibrillator (ICD) may be required. The patient should be advised to report symptoms of chest pain, prolonged dyspnea, or syncope promptly. First-degree relatives of those affected should be referred for evaluation.
idiopathic dilated cardiomyopathyAbbreviation: IDC
General supportive therapy includes rest, weight control, abstinence from tobacco, and moderate exercise at a level that does not cause symptoms. A salt-restricted diet is recommended. Therapy includes the use of vasodilators, such as ACE inhibitors, and diuretics like furosemide. Anticoagulants are important to prevent thrombus formation. IDC is a principal indication for cardiac transplant.