What intervention is most effective in preventing sudden cardiac death in patients with hypertrophic cardiomyopathy?

Hypertrophic cardiomyopathy is a genetic myocardial disorder with left ventricular hypertrophy, diastolic dysfunction, dynamic outflow obstruction, and risk of ventricular arrhythmias. It predisposes to sudden cardiac death due to malignant tachyarrhythmias, especially in young individuals and during exertion. Rationale: A. Implantation of a cardioverter-defibrillator provides continuous rhythm monitoring and delivers immediate defibrillation for life-threatening ventricular arrhythmias. It is the most effective intervention for preventing sudden cardiac death. This directly addresses risk of ventricular tachyarrhythmias and fatal cardiac events. B. Daily diuretic therapy reduces preload and relieves symptoms of congestion but does not prevent arrhythmias. Excessive preload reduction may worsen outflow obstruction. This intervention does not target the primary risk of sudden death in hypertrophic cardiomyopathy. C. Beta-blockers improve diastolic filling and reduce heart rate, decreasing symptoms such as chest pain and dyspnea. However, they do not eliminate the risk of fatal arrhythmias. This therapy supports symptom control but not definitive arrhythmia prevention. D. Lifestyle modifications such as reduced salt intake and controlled exercise improve overall cardiovascular health. However, they do not significantly reduce risk of lethal arrhythmias. These measures are supportive but ineffective for preventing sudden cardiac death.