Effect of Yoga-Based Cardiac Rehabilitation on Heart Rate Variability: Randomized Controlled Trial in Patients Post-MI

Abstract

Autonomic dysfunction is an independent predictor of cardiovascular and all-cause mortality after myocardial infarction (MI). We tested the effects of a 12-week yoga-based cardiac rehabilitation program on heart rate variability (HRV) in 80 patients post-MI. This randomized controlled trial with two parallel groups was carried out in a tertiary care institution in India. The yoga group received 13 hospital-based structured yoga sessions as an adjunct to standard care. Control group participants received enhanced standard care involving three brief educational sessions with a leaflet on the importance of diet and physical activity. HRV was measured in all participants with lead II electrocardiogram (ECG) signals. One yoga group patient's data were excluded due to ECG abnormalities. Baseline measurement was done 3 weeks post-MI, and postintervention assessment took place at the 13th week. HRV frequency and time domain indices were analyzed. There were no significant between-group differences in the HRV time domain indices. Frequency domain indices showed significant between-group differences in HF power (absolute) (yoga vs. control: 114.42 [−794.80–7,993.78] vs. −38.14 [−4,843.50–1,617.87], p = 0.005) and total power (nu) (yoga vs. control: 44.96 [21.94] vs. −19.55 [15.42], p = 0.01) with higher HF power and total power (nu) in the yoga group. It should be noted that these results cannot be generalized to high risk patients. Respiratory frequency control to check for influence of respiratory rate on RR interval was not evaluated. This short-term yoga-based cardiac rehabilitation program had additive effects in shifting sympathovagal balance toward parasympathetic predominance while increasing overall HRV in optimally medicated post-MI patients.

Comparative immediate effect of different yoga asana on cardiac autonomic rhythm in healthy young volunteers

“…Our study showed the HRV has good specificity and positive predictive value for the quantifying autonomic response of PD and AD. Similarly, Christa E et al 4 observed in their study in frequency domain indices Our finding shows backward bending is superior to forward bending and should be included in lifestyle intervention to reduce stress and anxiety disorder; also reported by Chu I.H et al 5 in his study that a 12-week yoga program was effective in increasing parasympathetic tone and reducing depressive symptoms and perceived stress in women with elevated depressive symptom. Prevesioly Hewett ZL et al 6 found that a 16-week Bikram Yoga program did not increase the high-frequency power components of HRV.…”

Yoga-Based Cardiac Rehabilitation: Current Perspectives from Randomized Controlled Trials in Coronary Artery Disease

“…Christa et al published data in 2019 which compared heart rate variability following acute MI in patients who underwent their 12-week yoga programme compared to standard care which did not include an exercise-based rehabilitation regime. 17 They found that in patients undergoing optimal medical therapy with standard education advice, the addition of yoga interventions improved parasympathetic activity and overall cardiac autonomic tone.…”

Yoga: A Potential Adjunct Therapy to Current Rehabilitation Pathways in Cardiac Conditions and Stroke

“…Both heart rate variability and endothelial function are also indicators of cardiovascular health. In a recent randomised controlled trial involving 80 heart attack survivors, participants in a 12-week yoga-based cardiac rehabilitation program had favourable effects on heart rate variability (HRV) compared to participants in a standard care cardiac rehabilitation involving only education [49]. In a pilot study involving 33 people who were in a 6-week yoga program, those with an established heart disease (n=10) observed a modest improvement in endothelial function from pre-to postprogram (p<.09) [50].…”