The effects of unilateral forced nostril breathing on the heart.

Three experiments are described that employ impedance cardiography to monitor the effects of unilateral forced nostril breathing (UFNB) on the heart. Experiment 1 includes 7 subjects (4 males, 3 females) with a respiratory rate of 6 breaths/min (BPM). Experiment 2 includes 16 trials using one subject to examine the intraindividual variability, at 6 BPM. Experiment 3 includes 10 trials with the same subject in experiment 2, but with a respiratory rate of 2-3 breaths/s. This rapid rate of respiration is a yogic breathing technique called "breath of fire" or "kapalabhatti" and employs a very shallow but rapid breath in which the abdominal region acts like a bellows. All 3 experiments demonstrated that right UFNB increases heart rate (HR) compared to left. Experiment 1 gave 7 negative slopes, or lowering in HR with left nostril breathing and 7 positive slopes, or increases in HR with right nostril breathing, p = .001. The second and third experiments showed differences in HR means in which right UFNB increases HR more than left, p = .013, p = .001, respectively. In experiment 2 stroke volume was higher with left UFNB, p = .045, compensating for lower HR. Left UFNB increased end diastolic volume as measured in both experiments 1 and 2, p = .006, p = .001, respectively. These results demonstrate a unique unilateral effect on sympathetic stimulation of the heart that may have therapeutic value.