Meta-Analysis of Effects of Voluntary Slow Breathing Exercises for Control of Heart Rate and Blood Pressure in Patients With Cardiovascular Diseases.

Rising heart rate (HR) and elevated blood pressure (BP) cause a greater frequency of cardiovascular events. Many patients cannot maintain target HR and BP using pharmacological therapies. To evaluate the effectiveness of voluntary slow breathing exercises in reducing resting HR and BP, we searched Embase (1974 to April 2016), PubMed (1966 to April 2016), the Cochrane Central Register of Controlled Trials (issue 4, April 2016), and PEDro (www.pedro.org.au; 1999 to April 2016). The primary outcome was the mean change in HR at rest. Secondary outcomes included changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) as well as compliance with the breathing training. Finally, we included 6 studies consisting of 269 subjects. Practice of the breathing exercises resulted in statistically significant HR reduction (mean difference: -1.72 beats/min, 95% CI -2.70 to -0.75). Reductions were seen in SBP (mean difference: -6.36 mm Hg, 95% CI -10.32 to -2.39) and DBP (mean difference: -6.39 mm Hg, 95% CI -7.30 to -5.49) compared with the controls. Trial durations ranged from 2 weeks to 6 months. In conclusion, the existing evidence from randomized controlled trails demonstrates that short-term voluntary slow breathing exercises can reduce resting HR, SBP, and DBP for patients with cardiovascular diseases.