All are true about hyperophic obstructive cardiomyopathy, except

Ref Harrison 19 th ed pg 1569 HYPEROPHIC CARDIOMYOPATHY Management focuses on treatment of symptoms and prevention of sudden death and stroke . Left ventricular outflow tract obstruction can be controlled medically in the majority of patients. b-Adrenergic blocking agents and L-type calcium channel block- ers (e.g., verapamil) are first-line agents that reduce the severity of obstruction by slowing hea rate, enhancing diastolic filling, and decreasing contractility