Effect of Tai Chi training on baroreflex sensitivity and heart rate variability in patients with coronary heart disease.

Tai Chi is a traditional Chinese conditioning exercise that has been used to integrate slow movements, controlled breathing, and mental concentration. The aim of the study was to determine whether Tai Chi training in addition to cardiac rehabilitation would result in a shift toward increased vagal activity of autonomic markers, such as baroreflex sensitivity (BRS) and heart rate variability (HRV). Twenty patients with coronary heart disease (CHD) (male/female: 13/7, mean age: 67.8 +/- 4.2 years, mean interval time after a coronary event: 19.8 months) completed this study. The Tai Chi group (n = 10) practiced supervised Tai Chi training once a week and home-based Tai Chi training three times a week together with conventional cardiac rehabilitation for one-year. The control group (n = 10) conducted the conventional cardiac rehabilitation only. BRS and HRV were evaluated at the baseline and after one-year of Tai Chi training. Compared with the controls, patients in the Tai Chi group showed statistically significant improvement in BRS (P = 0.036). These associations persisted after adjustment for age and other covariates. On the other hand, there were no significant trends seen in HRV. Additional Tai Chi training during cardiac rehabilitation may augment reflex vagal regulation, which adds importantly to knowledge of cardiac rehabilitation on autonomic regulation and clinical management of CHD.