Randomized Trial: A Pilot Study Investigating the Effects of Transcendental Meditation and Yoga Through Retinal Microcirculation in Cardiac Rehabilitation.

A pilot study of cardiac patients after heart surgery compared standard exercise therapy with groups that added 20 minutes of yoga or transcendental meditation twice daily during four weeks of rehabilitation. Retinal microcirculation—measured as central retinal artery equivalent, central retinal vein equivalent, and artery-to-vein ratio from non-mydriatic retinal images—showed no significant differences among the three groups over the course of rehabilitation. The authors conclude that neither yoga nor meditation produced measurable changes in retinal microcirculation in this setting, but suggest the findings provide preliminary information for future research on these underutilized approaches in cardiac rehabilitation.

Study at a glance

Abstract

Background/Objectives: Cardiovascular diseases are a leading cause of death, and psychosocial stress is considered a contributing factor to these issues. With the rising number of heart surgeries, proper rehabilitation post-surgery is essential. Previous studies have demonstrated the positive impact of yoga and transcendental meditation on the cardiovascular system. This pilot study aimed to investigate the effects of yoga and transcendental meditation on retinal microcirculation in cardiac patients before (admission), after (discharge), and following (3 weeks after discharge) rehabilitation. Methods: This study examined changes in retinal microcirculation in three rehabilitation groups of patients after heart surgery. The control group received standard exercise therapy, while the meditation group incorporated 20 min of meditation, and the yoga group incorporated 20 min of yoga practice, twice per day for the duration of four weeks of rehabilitation. Retinal images were captured using a non-mydriatic digital retinal camera (Canon CR-2, Canon Medical Systems Europe B.V., Netherlands), and the microcirculation parameters central retinal artery equivalent, central retinal vein equivalent, and artery-to-vein ratio were analyzed using MONA REVA software ((version 2.1.1), VITO, Mol, Belgium). Repeated measures ANOVA was performed to evaluate differences between the three groups in the course of rehabilitation. Results: None of the parameters revealed significant differences in retinal microcirculation between the three rehabilitation groups. Conclusions: The study evaluating changes in retinal microcirculation, as an indicator of central circulation in cardiac patients undergoing rehabilitation, did not observe any significant changes. As yoga and meditation are underestimated approaches in cardiac rehabilitation, this pilot study acts as a basis for providing preliminary information for future studies to encourage the research community to fill the gap in this area.