People that are diagnosed with hypertrophic cardiomyopathy, or HCM are often told to stop participating in competitive sports because there is a greater risk of sudden cardiac death from the disease. Currently, guidelines recommend that HCM patients limit the amount of intense exercise they do, as it could cause a ventricular arrhythmias. However, new work has indicated that a change in those guidelines may be in order. It now seems that patients diagnosed with HCM should be including moderate exercise in their routines. The report was published in the Journal of the American Medical Association and is summarized in the following video.
An abnormal thickening of the heart muscle makes it much more difficult for the heart to efficiently pump blood, and HCM is the result. It is the most common genetic disease of the heart, and is a leading cause of cardiac death in younger people.
The work was done by scientists at the University of Michigan, along with a team from Stanford University and the VA Palo Alto Health Care System; it was presented at the Annual Scientific Session of the American College of Cardiology. Previous research has shown that after a diagnosis of HCM, the activity level of patients tends to drop compared to the population at large.
"We are challenging the idea that exercise is dangerous for these patients," said Dr. Sharlene Day, a Cardiologist and Associate Professor at Michigan Medicine. "And we show that it can actually be beneficial."
The scientists designed a randomized clinical trial that included 136 patients between the ages of 18 and 80 that had HCM. The researchers determined that there is a statistically significant increase in maximal oxygen consumption (or VO2 max, a measure of the aerobic fitness in an individual) over 16 weeks in those who followed moderate exercise routines compared to participants who went about normal activities without moderate exercise. For this research, moderate exercise consisted of walking, jogging, biking, or using an elliptical machine for at least 20 minutes, three times per week. The participants did not perform any interval or weight training.
"We have those images entrenched in our brains of young, healthy athletes collapsing suddenly in the middle of a competition, and these devastating events trigger a visceral response," explained Dr. Sara Saberi, an Assistant Professor and Cardiologist at Michigan Medicine. "But by limiting exercise, we're creating another set of health problems that stem from obesity, like coronary heart disease, diabetes, obstructive sleep apnea, depression and anxiety. The findings show patients that follow an exercise prescription can actually train and improve their functional capacity."
The researchers noted that an evaluation of the long-term effects of exercise on patients with HCM is yet to be done; this study lays the foundation for additional work.