Yoga for Paroxysmal Atrial Fibrillation: An Ancient Solution to an Emerging Problem?
August 20, 2013
Editor's Note: Based on Lakkireddy D, Atkins D, Pillarisetti J, et al. Effect of yoga on arrhythmia burden, anxiety, depression, and quality of life in paroxysmal atrial fibrillation: the YOGA My Heart Study. J Am Coll Cardiol 2013;61:1177-82.
Atrial fibrillation (AF) is an increasingly prevalent cardiac arrhythmia, associated with increased morbidity and mortality, as well as substantial health care costs.1 Patients with AF have an increased incidence of depression and anxiety, presumably due to impairment in quality of life (QoL).2, 3 Yoga has been shown to reduce the symptoms of depression and anxiety and result in QoL improvement.4 In this context, the YOGA My Heart Study (NCT00798356) investigated the effects of yoga training on AF burden, QoL indicators, anxiety, and depression.5
The YOGA My Heart Study was a single center, prospective, self-controlled, pre-post cohort study. The study enrolled patients with paroxysmal AF between 18 and 80 years of age. Patients were considered ineligible if they had a history of AF ablation within three months, life expectancy <1 year, advanced heart failure, contraindication for yoga training, or if they had practiced any form of yoga in the preceding six months. Each patient in the study served as his or her own control. The study started with a three-month control period, followed by a three-month yoga intervention phase, during which all patients underwent structured Iyengar yoga training at least twice weekly. During the study period patients were instructed to record, using a symptom diary and a cardiac nonlooping event monitor, all episodes they felt that were consistent with symptoms of AF and at least an additional recording per day if they were asymptomatic. The primary outcomes of the study included change in symptomatic AF, asymptomatic AF and symptomatic non-AF episodes. The latter was defines as an episode associated with symptoms but no AF on the monitor. Secondary outcomes included change in Short Form 36 quality of life score, Zung self-assessment anxiety score (SAS) and Zung self-assessment depression score (SDS).
Out of 52 enrolled patients, 49 patients (47% male) completed the study. Patients had a mean age of 61 ± 11 years and mean duration of AF was approximately five years. The majority of patients had symptomatic AF (87.7%) and was on antiarrhythmic medication (77.6%).
Yoga training significantly reduced the number of symptomatic AF episodes (3.8 ± 3 vs. 2.1 ± 2.6; p < 0.001), symptomatic non-AF episodes (2.9 ± 3.4 vs. 1.4 ± 2.0; p < 0.001), and asymptomatic AF episodes (0.12 ± 0.44 vs. 0.04 ± 0.20; p < 0.001).
At the end of the intervention phase, yoga training was associated with significantly reduced anxiety and depression scores (p < 0.001), and significantly improved the physical functioning, general health, vitality, social functioning, and mental health domains of the QoL score (p = 0.017, p < 0.001, p < 0.001, p = 0.019, and p < 0.001; respectively).
In patients with paroxysmal AF, yoga training may reduce symptoms, arrhythmia burden, anxiety, and depression, and improve several parameters of quality of life.
AF imposes a substantial socioeconomic burden in Western societies, which according to estimates from the European Union and the USA is expected to increase significantly in the next 50 years.1, 6 Current management of AF patients is aimed at reducing symptoms and at preventing severe complications, with antithrombotic therapy and control of the ventricular rate.7, 8 These therapies may alleviate symptoms; however, symptom relief may require additional rhythm control therapy (i.e., antiarrhythmic drugs or catheter ablation). Both these therapies are associated with increased costs which tend to equalize at approximately five years.9
This proof-of-concept study by Lakkireddy et al. provides evidence that yoga may be a low-cost intervention with a complementary role in the reduction of symptomatic AF episodes or AF burden. Given that in the following years elderly patients will constitute the vast majority of AF patients,1 the relative safety of yoga training, and several added benefits of yoga, such as the improvement in the QoL, the reduction of anxiety and depression, and the beneficial role in improving mobility and preventing falls,10 make the findings of this study all the more pertinent.
The mechanism, however, by which yoga training achieved a reduction in AF burden remains unclear. At the end of the yoga intervention period, patients had a significant reduction in heart rate, systolic and diastolic blood pressure. Blood pressure reduction by yoga is well-studied and a recent meta-analysis has demonstrated that yoga is effective in reducing both systolic and diastolic blood pressure.11 Evidence suggests that one way this effect is mediated is through slow yogic breathing, which increases baroreflex sensitivity and decreases both systolic and diastolic blood pressure.12 The drop in systolic blood pressure observed in the YOGA My Heart Study correlated with the reduction in AF episodes, suggesting a link, which could involve left ventricle afterload reduction.
Moreover, since the influence of the autonomic nervous system on triggering and perpetuation of AF is well established,13 the modulation of autonomic tone by yoga training may restore a balance between sympathetic and parasympathetic activity and prevent AF episodes.14
Other potential mechanisms for the reduction of AF burden, as presented by Lakkireddy et al., could include improvement in endothelial dysfunction and reduction of inflammation, which may reduce susceptibility to AF.
The findings of the YOGA My Heart Study call for further investigation in order to elucidate the involved mechanisms and fully identify the beneficial effects of yoga for patients with AF.
First of all, the hypothesized yoga-induced changes in autonomic tone and in markers of systemic inflammation or endothelial function need to be confirmed in new experimental studies.
Another significant question we need to address is the number of yoga sessions per week required to achieve a sustainable, long-term, antiarrhythmic effect. In this study, counter-intuitively, the greatest reduction in AF episodes was achieved by the patients with the least sessions (≤2), whereas the greatest reduction in systolic blood pressure and heart rate was achieved by the patients with the greatest number of sessions (>4).
Finally, the idea of introducing yoga training in patients with permanent AF as a complementary therapy for adequate rate control and QoL improvement is intriguing, and a new study addressing this would be equally interesting.