Pulmonary arterial hypertension (PAH) is characterized by a mean pulmonary arterial pressure of >20 mmHg, measured by right heart catheterization at rest. PAH begins in the small arteries of the pulmonary vasculature and is characterized by increased vasoconstriction. Pulmonary vasodilatation induced by perivascular nerve stimulation usually occurs with nitric oxide (NO). A decrease in the airway wall concentration of NO was detected in patients with PAH. It has been reported that patients with PAH have a mild to moderate decrease in lung volumes associated with disease severity. A decrease in exercise capacity and respiratory muscle strength has been reported in patients with PAH.~Osteopathic Manipulative Therapy (OMT) is a well-known manual therapy approved by World Health Organization. A single-session of OMT was found to increase pulmonary function, inspiratory muscle strength, oxygen saturation, and to reduce dyspnea and fatigue in individuals with severe chronic obstructive pulmonary disease. It has been observed that OMT increases parasympathetic activity and reduces blood pressure in patients with hypertension.~Pranayama breathing is an important component of of yoga. It has been reported that yoga respiratory training increases vagal tone and reduces sympathetic activity, increases vital capacity, controls heart rate and blood pressure, and improves respiratory muscle strength.~No study investigating the effects of adding yoga respiratory training to osteopathic manipulative treatment in patients with PAH was found in the literature. The investigators aimed to explore the effects of a combined intervention consisting of OMT and yoga breathing exercises, as well as OMT alone on exhaled NO level, pulmonary function, respiratory and peripheral muscle strength, and exercise capacity in patients with PAH.
The investigators planned a randomized controlled study to investigate the effects of adding yoga respiratory training to osteopathic manipulative treatment (OMT), and OMT alone on exhaled nitric oxide level and cardiopulmonary function in patients with pulmonary arterial hypertension (PAH). Our hypothesis is that combined intervention including OMT and yoga respiratory training may improve exhaled nitric oxide level and cardiopulmonary function in patients with PAH.