Yoga shows remarkable benefit for vasovagal syncope patients, JACC study.

Treatment of vasovagal syncope (VVS) patients has hitherto proven to be difficult, with various treatment modalities showing a modest benefit if any. Several studies have shown yoga to favorably modulate the autonomic system by balancing the central and peripheral sympathetic–parasympathetic drives. Further exploring these observations through a randomized control trial, researchers from AIIMS,  conducted the LIVE Yoga study. The results that have now been published in JACC CE show that Yoga as adjunctive therapy is superior to standard therapy alone in reducing the symptomatic burden and improving quality of life (QoL) in patients with recurrent VVS.

VVS is a type of reflex syncope mediated by emotional or orthostatic stress and is associated with an increased and imbalanced autonomic activation. Recent studies have shown the benefit of yoga in patients with VVS. LIVE Yoga was a randomized controlled trial (RCT) conducted to assess the effectiveness of yoga as adjuvant therapy in patients with VVS.

Patients with recurrent VVS were randomized to receive either a specialized yoga training program in addition to current guideline-based therapy (intervention arm, group 1) or current guideline-based therapy alone (control arm, group 2).

The primary outcome was a composite of the number of episodes of syncope and presyncope at 12 months. Secondary outcomes included QoL assessment by World Health Organization Quality of Life Brief Field questionnaire (WHOQoL-BREF) scores and Syncope Functional Status Questionnaire scores at 12 months, head up tilt test, and heart rate variability at 6 weeks.

Fifty-five patients were recruited from the Out-Patient Department of the Cardiothoracic Sciences Center, AIIMS (New Delhi). Thirty patients were randomized to intervention and 25 were randomized to control groups, respectively

The mean number of syncopal or presyncopal events at 12 months was 0.7 ± 0.7 in the intervention arm compared to 2.52 ± 1.93 in the control arm ( P <0.01). In the intervention arm, 43.3% patients remained free of events versus 16.0% patients in the control arm ( P =0.02).

QoL at 12 months showed significant improvement of all Syncope Functional Status Questionnaire scores and 2 domains of WHOQoL-BREF scores.The margin of benefit was sizeable, with a mean episode reduction of 1.82 events at 12 months.

Pharmacological options including beta blockers, autonomic modulators, and mineralocorticoids have yielded mixed results for VVS. The inadequacies of currently available treatment options have led to the exploration of traditional forms of medicine, including yoga. The specially designed yoga module for this trial included postures, breathing, and relaxation techniques that were chosen keeping in view the pathophysiology of VVS.

"We postulate that positive effects of yoga in this study could be related to a multidimensional effect of this intervention acting through both central and peripheral mechanisms, including physical, psychological, and autonomic pathways", noted authors in discussion.

Regular practice of asanas which comprise various isotonic postures involving different muscle groups leads to enhanced muscle and vascular tone in addition to building muscle strength. Enhanced vascular and muscular tone, especially in lower limbs, not only blunts the venodilation phase of a syncope episode but may also accelerate the venous return (Figure 1).

Yoga breathing and relaxation techniques have been shown to increase vagal tone and improve autonomic balance which could potentially curtail the sympathetic overdrive phase and interrupt the activation of the c-mechanoreceptors, which is a critical step in the syncope cascade.

Larger studies may further delineate the effect of yoga on clinical outcomes and QoL facilitating the incorporation of yoga into management guidelines of VVS.

Source: JACC CE: DOI: 10.1016/j.jacep.2021.09.007