Can Aerobic Exercise Help Diastolic Dysfunction?

When the heart beats, it squeezes and relaxes. The squeezing phase of the cycle is when the heart muscle contracts and ejects blood into the arteries and it is called systole. The relaxation phase is when the heart fills with blood to prepare for the next heartbeat and it is called diastole.

Sometimes, a stiffening of the heart muscle affects the diastolic phase of the heartbeat, making it more difficult for the relaxing heart muscle to completely fill with blood. This problem is known as diastolic dysfunction, which can eventually lead to diastolic heart failure. As some studies indicated, up to 75 percent of elderly women had diastolic dysfunction. While it is less common in men, its risk increases with age and studies have shown prevalence of 50 percent in men older than 70.

High blood pressure is the most common cause of diastolic dysfunction. Abnormal rhythms, fast heart rate, sudden increase in blood pressure, increased salt intake, excessive fluid consumption and insufficient blood flow to the heart muscles may stress the heart and lead to diastolic dysfunction.

Patients with diastolic dysfunction typically have a limited exercise capacity. They tend to complain of dyspnea (shortness of breath) easily on activities which they could do comfortably in the past. But recent evidence strongly suggests that a program of aerobic exercise can actually improve the symptoms of diastolic dysfunction and enhance quality of life. Patients may begin to reverse the stiffness of the heart muscle and prevent the onset of diastolic heart failure.

Randomized trials in patients with diastolic dysfunction have demonstrated that regular aerobic training (but not weight lifting or strength training) for 3 to 4 months can significantly improve exercise capacity, symptoms of shortness of breath with exertion, and quality of life measures. There is evidence indicating that strength training may worsen the problem by causing the heart muscle to hypertrophy (thicken) in a way that increases cardiac stiffness. Aerobic exercise, including walking, cycling, or jogging, is a form of exercise in which the energy demands of the muscles are met by consuming oxygen.

The latest findings published January 8, 2018 in journal ‘Circulation’ reported that exercise can reverse damage to sedentary, aging hearts and provide protection against future heart failure by preventing the increase in cardiac stiffness with sufficient exercise, and if it is begun in time. The study was conducted by researchers at the Institute for Exercise and Environmental Medicine (IEEM), which is a collaboration between UT Southwestern Medical Center and Texas Health Presbyterian Hospital Dallas.

Researchers pointed out that heart stiffening often shows up in middle age in people who do not exercise and are not fit, leaving them with small, stiff chambers that cannot pump blood as well. At the end of the 2-year study, those who had exercised for 30 minutes 4 to 5 times a week showed an 18 percent improvement in their maximum oxygen intake during exercise and a more than 25 percent improvement in compliance, or elasticity, of the left ventricular muscle of the heart.