The Effects of Inspiratory Muscle Training in Patients With Heart Failure and Obstructive Sleep Apnea Syndrome

The Effects of Inspiratory Muscle Training in Patients With Heart Failure and Obstructive Sleep Apnea Syndrome

The Effects of Inspiratory Muscle Training in Patients With Heart Failure and Obstructive Sleep Apnea Syndrome

Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, Brazil, Conselho Nacional de Desenvolvimento Científico e Tecnológico

This research aims to evaluate the effects of inspiratory muscle training (IMT) on apnea hypopnea index, sleepiness, sleep quality, cognitive function, motor task, executive function, quality of life, chemoreflex sensitivity and vagal modulation of heart rate in patients with heart failure and obstructive sleep apnea syndrome.

Patients with heart failure will be selected through the Outpatient of the Rio Grande do Sul, for convenience. Subsequently, patients will be subjected to test respiratory muscle strength (manometer), respiratory muscle endurance, portable polysomnography, sleepiness, sleep quality, cognitive function (mini-mental state examination), motor task (execution of a sequence of digital movements), executive function, quality of life (SF-36), maximum exercise testing, chemoreflex sensitivity (peripheral chemoreflex by transient hypoxia and central chemoreflex by hypercapnic hyperoxia) and vagal modulation of heart rate (spectral analysis) before the start of the training protocol. Patients will be randomized to inspiratory muscle training or control group. Inspiratory muscle training will be performed for 30 minutes a day, 7 days a week, for 12 weeks with muscle training device (PowerBreathe). There will be a weekly monitoring in the Clinical Research Center of the institution where the maximal inspiratory pressure (MIP) and respiratory training techniques will be reassessed and readjusted (30% of MIP). The control group will be submitted to respiratory training techniques with muscle training device (PowerBreathe) without load. After this period, all initial tests will be reassessed. A group study with 15 heart failure patients without obstructive sleep apnea syndrome will be included.

Participants will be submitted to a linear pressure resistance (PowerBreathe) with an inspiratory load of 30% of maximal inspiratory pressure (adjusted weekly), seven days a week, session duration of 30 minutes for 12 weeks. During training, participants will be instructed to maintain diaphragmatic breathing with a breathing rate of 15-20 cycles/min. Inspiratory load will be set at 30% of maximum static inspiratory pressure, and weekly training loads will be adjusted to maintain 30% of MIP. Each week, six training sessions will be held at home and a training session will be supervised in the research center.

Participants will be submitted to inspiratory muscle training with the same equipment as the intervention group, but without a load generating resistance. Sham IMT Participants will receive IMT for 30 min, 7 times per week for 12 weeks using Inspiratory muscle trainer device (PowerBreathe). During training, participants will be instructed to maintain diaphragmatic breathing with a breathing rate of 15-20 cycles/min, but without a load generating resistance. Each week, six training sessions will be held at home and a training session will be supervised in the research center.

Participants will be submitted to a linear pressure resistance (PowerBreathe) with an inspiratory load of 30% of maximal inspiratory pressure (adjusted weekly), seven days a week, session duration of 30 minutes for 12 weeks. During training, participants will be instructed to maintain diaphragmatic breathing with a breathing rate of 15-20 cycles/min. Inspiratory load will be set at 30% of maximum static inspiratory pressure, and weekly training loads will be adjusted to maintain 30% of MIP. Each week, six training sessions will be held at home and a training session will be supervised in the research center.

Participants will be submitted to inspiratory muscle training with the same equipment as the intervention group, but without a load generating resistance. Sham IMT Participants will receive IMT for 30 min, 7 times per week for 12 weeks using Inspiratory muscle trainer device (PowerBreathe). During training, participants will be instructed to maintain diaphragmatic breathing with a breathing rate of 15-20 cycles/min, but without a load generating resistance. Each week, six training sessions will be held at home and a training session will be supervised in the research center

assessed by the execution of a sequence of digital movements [in time required and number of execution errors]

measured by Trail Making Test. In Part A, participants are asked to link numbered points randomly distributed on a sheet of paper in ascending order according to numbers. In Part B, the participants are asked to link numbers and letters alternately [in time of test performance, counts the number of errors, and calculates the difference in times: B-A.].

It will be assessed using of treadmill stress test with Bruce protocol. The peak oxygen consumption will be estimated according to the method established by the American College Sports Medicine [in mL.kg-1.min-1]

peripheral chemoreflex will be assessed by transient hypoxia [in L.min-1.mmHg] and central chemoreflex by hypercapnic hyperoxic in [L. min-1. %SatO2]

Inclusion Criteria: Heart failure patients with obstructive sleep apnea- hypopnea Heart failure patients without sleep apnea Left ventricle fraction ejection < 51 % for men and < 53% for woman Must be clinically stable New York Heart Association I, II and III Without changes in medication for the last three months. Exclusion Criteria: Unstable angina Atrial fibrillation Acute myocardial infarction (<6 months) Recent heart surgery (<6 months) Chronic metabolic disease Infectious disease Anemia Severe hypoxemia Neuromuscular disease Diabetes mellitus Obesity Use of continuous positive airway pressure Smoking Pulmonary disease (forced vital capacity <80% of predicted and / or forced expiratory volume in one second <70% predicted).

The volunteers will receive the results of the evaluations pre and post-intervention by the of the study.