Background: Physical activity is recommended to individuals with hypertrophic cardiomyopathy (HCM) as a management option to reduce disease burden. However, over 50% of individuals with HCM are not meeting the recommended physical activity guidelines. Beta-blockers (BB) are prescribed to individuals with HCM to aid symptom management, but the effects on physical activity are relatively unknown. The aim of this study was to investigate the associations between accelerometry and echocardiographic measurements in individuals with HCM. Data described as median unless otherwise stated.
Methods: Twenty-one individuals with HCM (males, n=15, age (mean±SD) 52±15 years old, body mass index (BMI) 29 (25-31) kg/m2, prescribed BB, n=11, left atrial volume index (LAVI) 32 (30-35) mL/m2 and stroke volume (SV) 55 (44-65) mL) had accelerometry and echocardiographic measurements recorded. Accelerometry categories were measured over 7 days using wrist-worn accelerometers (GENEActiv, ActivInsights Ltd., United Kingdom). Echocardiographic measures were taken in the rest-supine position and included LAVI and SV.
Results: In individuals with HCM, time spent in 1 to 5 minute bouts of light intensity physical activity was positively correlated with LAVI (r=0.55, p<0.01). However, time spent in 1 to 5 minute bouts of light physical activity was negatively correlated with SV (r=-0.50, p<0.05). A positive trend was found between time spent in 10 minute bouts of moderate to vigorous physical activity and SV (r=0.20, p=0.44). The same trends applied for those prescribed BB versus those who were not.
Conclusion: In individuals with HCM, our findings highlight that there are associations between light and moderate to vigorous physical activity and cardiac structure and function that requires further explorations.