Complex Exercises of the Respiratory Muscles Plus Aerobic Training vs. Aerobic Training in Patients With СHF
Condition: Heart Failure
MeSH terms: Heart Failure
Study type: Interventional

Summary: 
      The aim of the study is to test the hypothesis that the physical rehabilitation starting with
      respiratory training followed by the aerobic exercises will have a more pronounced effect on
      clinical and functional indicators than the currently used physical rehabilitation based on
      aerobic training alone
    

Detailed description: 
      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.
    

Intervention name(s): respiratory muscles training; sham respiratory muscles training; aerobic training
Intervention type(s): Other; Other; Other
Intervention description(s): 4 weeks respiratory muscles training aimed on respiratory muscles endurance and lengthening expiration time; 4 weeks sham respiratory muscles training with the help of breathing simulators, with a breathing resistance level set at 0; 12 weeks treadmill walking
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Parallel assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: CHF; exercise; aerobic; respiratory muscle training