Exercise in Inherited Cardiomyopathies: Optimizing the Dose-Response Curve.

Exercise is generally considered beneficial for cardiovascular health, but for patients with inherited cardiomyopathies, exercise can be a source of anxiety due to concerns about arrhythmia risk and disease progression. In the general population, exercise avoidance can impact cardiometabolic health and diminished fitness is a risk factor for heart failure. At the other extreme, sustained high levels of exercise in competitive endurance athletes have been associated with an increased risk of some arrhythmias. Defining optimal threshold levels for exercise participation is not straightforward and one-size-fits-all recommendations are unlikely to be successful. In the context of inherited cardiomyopathies, the impact of exercise on myocardial function and arrhythmias depends on factors such as exercise frequency, intensity, and duration, as well as the type of cardiomyopathy, underlying genotype, and other unique intrinsic traits in each individual. This review outlines current knowledge with respect to the impact of exercise in hypertrophic, arrhythmogenic, and dilated cardiomyopathies based on studies in human cohorts and animal models. Several disease-specific and genotype-specific risk factors are highlighted, although our understanding of these factors remains incomplete. Importantly, although exercise activities remain restricted for those with high-risk features, emerging evidence suggests that moderate-to-high levels of exercise may be safe and beneficial for many patients. Harnessing the cardioprotective power of exercise holds enormous promise for expanding personalized strategies for cardiomyopathy treatment and prevention.