Pharmacologic Treatment of Symptomatic Hypertrophic Cardiomyopathy

Multicenter study of the efficacy and safety of disopyramide in obstructive hypertrophic cardiomyopathy

“…The most frequent approach is to substitute verapamil for beta-blocker (13,(42)(43)(44). Others support an alternate strategy of combining disopyramide with a beta-blocker (2,12,20,45).…”

“…Symptomatic HCM patients with outflow obstruction are generally treated initially with a beta-blocker, which may blunt gradients that are physiologically provoked with exercise and thereby improve symptoms. However, betablocking therapy is not expected to reduce resting gradient (7)(8)(9)(10)(11)(12) and may not control symptoms satisfactorily in some patients. For those patients with refractory obstruction and symptoms after a trial with beta-blockers, alternative drugs are required.…”

“…The decision to initiate disopyramide for any individual patient was made by the treating physician at the respective HCM center. This was an integrated judgment based on symptoms, echocardiographic findings, and the patient response to previously administered cardioactive drugs (2,12). All patients enrolled at participating U.S. institutions consented to the use of their medical information for research purposes.…”

“…Traditionally, negative inotropic drugs represent the firstline treatment for symptomatic patients with obstructive HCM. Beta-blockers, often administered first, may improve symptoms, but generally do not reduce outflow gradient at rest (7)(8)(9)(10)(11)(12). Verapamil has only a modest effect on outflow gradient and should be avoided in patients with particularly marked obstruction associated with severe symptoms (13,14).…”

“…Disopyramide, a type I antiarrhythmic drug, has considerable negative inotropic effects and represents a potential alternative drug regimen for obstructive HCM (2,12,(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). However, the efficacy of disopyramide in ameliorating outflow gradient and heart failure symptoms has been reported only in relatively small short-term studies (16 -25).…”