Heart of the matter: A GP’s guide to cardiac myosin inhibitors

Abstract

Hypertrophic obstructive cardiomyopathy (HOCM) is a heritable heart condition. It causes hypertrophy of the heart muscle and left ventricular outflow tract obstruction. Hypertrophic cardiomyopathy (HCM) is one of the most prevalent inherited cardiac disorders, with more than 1400 mutations discovered. Dizziness and shortness of breath commonly result from impaired diastolic filling and dynamic left ventricular outflow tract obstruction, both of which limit cardiac output, particularly during exertion. Individuals with HOCM may experience chest pain due to myocardial ischaemia in the absence of blockages in the coronary arteries. Traditional medical management includes beta-blockers, non-dihydropyridine calcium channel blockers and disopyramide, all of which aim to reduce myocardial contractility and improve diastolic filling. These agents have variable efficacy and tolerability. Cardiac myosin inhibitors are increasingly being used, and GPs need to be familiar with common side effects and drug interactions.