Effects of Respiratory Muscles Training on Cardiopulmonary Parameters and Quality of Life in Patients With Dilated Cardiomyopathy

Dilated cardiomyopathy is the most common type of heart failure and primary source of heart replacement globally. It is characterized by poor left ventricular function,enlargement of left ventricle and systolic dysfunction. The underlying cause of DCM in adults is usually coronary artery disease, but other causes include inflammatory heart disease, myocardial toxins, and genetic defects; approximately 30% to 35% of patients are reported to have a genetic form of dilated cardiomyopathy. Most common sign and symptoms of dilated cardiomyopathy are ankle swelling, dyspnea, fatigue, elevated jugular venous pressure elevated, pulmonary rales due to reduced cardiac function with low output and elevated intra cardiac pressures. Other sign and symptoms chest pain due to reduced coronary blood flow, palpitation, syncope and sudden cardiac death. There is reduced exercise tolerance with fatigue and dyspnea, contributing to poor prognosis and quality of life.

Chronic heart failure (CHF) patients have limited capacity to exercise and have impairments in breathing function.Respiratory muscle weakness is a part of the underlying cause for exercise intolerance in patients with heart failure with reduced ejection fraction.

Pharmacological and non pharmacological management is directed to reduce clinical sign and symptoms and control of disease progression and complications like sudden cardiac arrest. Physical rehabilitation is beneficial, effective and safe for functional limitation of DCM patients. A modified Bruce protocol is usually used to gradually increase exercise intensity in cardiac rehabilitation programs for patients with cardiomyopathy. Bruce protocol was used to observe fluctuations in heart rate through a quick increase of exercise intensity for a short period of time. Some patients are able to exercise with higher intensity safely, but many patients reported difficulties on treadmill exercise. This becomes even more difficult when the intensity of the treadmill exercise is increased.

Various studies have demonstrated the effects of exercise as well as inspiratory muscle training for improvement in patients with CHF and have considered it an important component of cardiac rehabilitation. Respiratory muscles training is commonly performed using inspiratory resistance devices but studies have proven that incentive spirometry could be an interesting alternative for clinical use for the cases where there is difficult to acquire the devices. Slow breathing treatment is safe and induces favourable effects in cardiopulmonary parameters, decreases rate of dyspnea, improves exercise performance and increases respiratory muscles and function. Deeper and slow breathing involves the use of diaphragm that is activated during slow breathing and does not increase respiratory workload.Respiratory muscles training is safe and improves physiologic parameters including an increase in oxygen saturation and improved exercise capacity, leading to an improvement in health status.

This study is intended to observed the overall effect of respiratory muscles training including slow breathing and incentive spirometry along with treadmill training according to bruce protocol for improvement in their ejection fraction, left ventricular dimensions , pulmonary function and quality of life.