The Effects of Mindfulness and Meditation on Vagally-Mediated Heart Rate Variability: A Meta-Analysis

Author: Lydia Brown1, Alora A Rando, Kristina Eichel, Nicholas T Van Dam, Christopher M Celano, Jeff C Huffman, Meg E Morris
1 La Trobe University, Melbourne, VIC, Australia Melbourne School of Psychological sciences, University of Melbourne, Parkville, VIC, Australia North Eastern Rehabilitation Centre, Healthscope Hospitals, Melbourne, VIC, Australia Suffolk University, Boston, Massachusetts, USA Department of Psychiatry and Human Behavior, Warren Alpert Medical School, Brown University, Providence, RI, USA. Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA Massachusetts General Hospital, Boston, Massachusetts, USA Harvard Medical School, Boston, Massachusetts, USA.
Conference/Journal: Psychosom Med
Date published: 2020 Dec 30
Other: Volume ID: Publish Ahead of Print , Special Notes: doi: 10.1097/PSY.0000000000000900. , Word Count: 233

Heart Rate Variability (HRV) is a marker of autonomic nervous system function associated with both physical and mental health. Many studies have suggested that mindfulness and meditation-based interventions (MBIs) are associated with improvements in HRV, but findings are mixed and to date no comprehensive meta-analysis has synthesized results.

Systematic literature searches were conducted using PsycINFO, Embase, Medline, CINAHL, ERIC and Scopus to identify randomized controlled trials (RCTs) investigating the effects of predominantly seated MBIs on resting-state vagally-mediated HRV. Risk of bias was judged using the Cochrane Risk of Bias tool.

Nineteen RCTs met criteria for inclusion in the meta-analysis. Random-effects meta-analysis found that MBIs were not efficacious in increasing vagally-mediated resting-state HRV relative to control conditions (Hedges' g = 0.38, 95% CI = - 0.014 to 0.77). When removing an outlier (g = 3.22), the effect size was reduced, confidence interval narrowed, and findings remained non-significant (g = 0.19, 95% CI = -0.02 to 0.39). High heterogeneity in results (I2 = 89.12%) could not be explained by a priori determined moderators including intervention duration, study setting and control type.

There is currently insufficient evidence to indicate that MBIs lead to improvements in vagally-mediated HRV over control conditions. Future large, well-designed RCTs with low risk of methodological bias could help add to the current evidence to elucidate any role MBIs might play in impacting HRV.HRV: heart rate variability; HF-HRV: high-frequency heart rate variability; MBI: mindfulness based intervention; RSA: respiratory sinus arrhythmia.

PMID: 33395216 DOI: 10.1097/PSY.0000000000000900