Yoga and Atrial fibrillation

Atrial fibrillation or irregular heart beat is a common heart ailment. It is highly prevalent both in the United States and worldwide. It afflicts 3 to 6 million individuals in the US and roughly 33 million globally (Circulation 2013, JACC 2014). Additionally, its prevalence increases with age (Framingham and Cardiovascular Health Study, Circulation 2001). It is associated with significant morbidity and mortality such as five times higher risk for stroke and twice the stroke related mortality, three times higher risk of heart failure and twice the prevalence of dementia. Moreover, the healthcare costs are staggering. The treatment of atrial fibrillation is not only costly, but are not optimal with success rates approaching 50-70% at one year with frequent recurrences (Calkins, Circulation 2012, Lakkireddy, JACC 2013). Moreover the treatments for atrial fibrillation involves rate and rhythm controlling anti-arrhythmic medications with its attendant toxicities some of which could be disabling. Invasive electrophysiological procedures such as catheter ablation have had considerable success in some select ideal individuals but are not curative. They are associated with upto 5% complication rate in advanced academic centers which includes stroke and mini-strokes, death, pulmonary vein stenosis, esophageal-atrial fistula, pneumonia, cardiac perforation and tamponade amongst other complications. However, it is refreshing to note that yoga, which is free, and non-invasive, if done regularly can provide immense complementary benefit in this population. Yoga lowered the burden and symptoms of atrial fibrillation, with significant impact on heart rate, blood pressure, anxiety and depression scores, and significantly improved the quality of life (Figure 1) (My Heart Study, Lakkireddy, JACC 2013).

Mechanism and biological explanation: Extreme non physiological fluctuation in autonomic tone, such as sympathetic surges, often precede atrial fibrillation episodes (Huang JL et al, Int J Cardiology, 1998). Persistent systemic and regional inflammation, oxidative stress and endothelial dysfunction promotes substrate changes such as atrial remodeling, fibrosis and ischemia that help sustain atrial fibrillation. Several studies suggest that practicing yoga can decrease systemic stress, down regulate the hypothalamic-pituitary-adrenal axis, which in turn can reduce sympathetic nervous system activity and increase parasympathetic activity. Yoga practice was shown to decrease blood pressure, improve endothelial function and reduce inflammation (Patel et al, LANCET 1975, Manchanda SC, JAPI 2000, and Gordon LA et al, BMC 2008). Yoga may prevent the AF initiation and perpetuation through its pleiotropic effects such as: 1) increasing the baseline parasympathetic tone; 2) suppressing extreme fluctuations in the two autonomic nervous system components; and 3) decreasing the pro- gression of the arrhythmia by preventing or minimizing atrial remodeling. Yoga resulted in significant improvement in quality of life parameters, anxiety, and depression in patients with atrial fibrillation. This likely is explained by yoga related attenuation of neurohormonal response to triggers of stress (MacLean et al, Psychoneuroendocrinology 1997).