Complex Exercises of the Respiratory Muscles Plus Aerobic Training vs. Aerobic Training in Patients With СHF

Changes in the respiratory muscles play an important role in the pathophysiology of exercise intolerance in CHF patients. The weakness of the respiratory muscles leads to a decrease in the efficiency of breathing and the formation of a pathological type of breathing, in which the inhalation time is prolonged, and the expiration time is shortened. Patients with weak respiratory muscles have impaired functional status, as determined by peak oxygen consumption. The violation of the ratio of inspiratory time / to the total time of the respiratory cycle is associated with an increase in the activity of the sympathoadrenal system. The positive effect of respiratory muscle training on MIP, MEP, peak VО 2, VE, VE / VCO 2 slope, VE oscillation, rhythm variability, and quality of life parameters is shown. Decreased oxygenation of the respiratory muscles during intense physical exertion in patients with CHF may increase respiratory failure and provoke hyperactivation of the inspiratory metaboreflex, thereby aggravating exercise intolerance due to a decrease in muscular-muscular system perfusion due to redistribution of blood flow. In addition, it was shown that fatigue of the respiratory muscles increases the activity of the sympathetic nervous system and reduces blood flow in the muscles of the inactive limb due to adrenergic vasoconstriction. This response is most likely associated with metabolic stimulation of small afferent type III and IV fibers of the respiratory muscles, especially the diaphragm. Respiratory muscle training can minimize the effects of inspiration metaboreflex activation and prolong the duration of exercise. In addition, several studies have shown that the strength of the respiratory muscles in patients with HF correlates with central hemodynamic indices at rest, including cardiac output, mean pulmonary pressure and pulmonary vascular resistance. Several studies have shown that the mechanism that improves exercise tolerance in patients with HF after training the respiratory muscles is to increase the blood supply to the muscles of the limbs at rest and during exercise. Thus, the mechanisms of the effect of the weakness of the respiratory muscles on the pathogenesis of a decrease in the functional ability of patients are well studied. Both respiratory muscular and aerobic exercises of moderate effectiveness are recommended by leading medical communities as an effective means to improve the functional ability of patients, improve quality of life parameters, improve symptoms and reduce hospital admissions (level of evidence Level 1). At the same time, respiratory muscle training is recommended as the beginning of physical rehabilitation in patients with IV FC HF, and moderate-intensity aerobic training is recommended for patients with FC I-III FC. Also, in individual works abroad, the effects of respiratory muscle training on clinical CHF. However, according to the investigator's information, no studies have been carried out on the study of the method of functional training, including training of the respiratory muscles, as an obligatory initial stage of physical rehabilitation of patients with any functional class of HF.