Impact of Breathing Training on Cardiac Patients' Recovery: Randomized Research Study

INTERVENTION: This is a three‐arm, randomized, double‐blind, controlled clinical study. The study will include 102 volunteers eligible for cardiac surgery who meet the eligibility criteria, randomized to inspiratory muscle strength training (IMT‐F), inspiratory muscle endurance training (IMT‐E), or inspiratory muscle control training (IMT‐C), with 34 participants in each group. Volunteers will be randomized using the website http://www.randomization.com. Participants and the researchers responsible for outcome assessment will be blinded to the study randomization. Training for all three groups will occur daily, once a day, and under supervision, in the pre‐cardiac surgery period, for at least five days until the day before the surgical procedure. Inspiratory muscle strength training (IMT‐F) group: strength training for 20 minutes at 60% of maximum inspiratory pressure (PImáx), with interval flow; five repetitions, two minutes of training and two minutes of rest, totaling 150 respiratory cycles. Inspiratory muscle training endurance group (IMT‐E): resistance training for 20 minutes at 30% of maximum inspiratory pressure (MIP), with continuous flow and pauses only if necessary; totaling 300 respiratory cycles. Inspiratory muscle training control group (IMT‐C): placebo training for 20 minutes at 10% of maximum inspiratory pressure (MIP), with interval flow; five repetitions, two minutes of training and two minutes of rest, totaling 150 respiratory cycles. In all groups, inspiratory muscle training (IMT) will be performed using an inspiratory threshold resistance device (Power Breath K5, HaB International Ltd., UK) CONDITION: Cardiovascular Surgical Procedures; Thoracic Surgery ; Cardiovascular Diseases PRIMARY OUTCOME: It is expected to find improvement in cardiorespiratory function, with a greater magnitude of gain in the inspiratory muscle strength training group (IMST) compared to the inspiratory muscle endurance training (IMET) and control inspiratory muscle training (CIMT) groups, verified by means of manovacuometry and spirometry, based on the finding of increase or stability of maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and lung volumes in the pre‐ and post‐operative periods of cardiac surgery It is expected to identify improvement in functional capacity, with more significant results in the inspiratory muscle strength training group (IMST) compared to the inspiratory muscle endurance training (IMET) and control inspiratory muscle training (CIMT) groups, evaluated by means of the 6‐minute walk test, based on the measurement of the distance covered in the pre‐ and post‐operative periods of cardiac surgery It is expected to observe positive effects on voice production, with superior results in the inspiratory muscle strength training group (IMST) compared to the inspiratory muscle endurance training (IMET) and control inspiratory muscle training (CIMT) groups, evaluated by means of self‐perception analysis using questionnaires, and through pitch sustain and loudness in the pre‐ and post‐operative periods of cardiac surgery INCLUSION CRITERIA: Volunteers aged 40 or older; with a medical prescription for physiotherapy; candidates for valve replacement (VT), coronary artery bypass grafting (CABG), or combined surgery (CABG + VT); clinically stable SECONDARY OUTCOME: It is expected to identify a reduction in frailty indexes, with more expressive results in the inspiratory muscle strength training group (IMST) compared to the inspiratory muscle endurance training (IMET) and control inspiratory muscle training (CIMT) groups, measured by means of questionnaires and physical tests, based on the analysis of vulnerability criteria and frailty phenotype It is expected to observe a gain in peripheral muscle strength, with superiority in the inspiratory muscle strength training group (IMST) compared to the inspiratory muscle endurance training (IMET) and control inspiratory muscle training (CIMT) groups, measured by handgrip strength and the five‐times sit‐to‐stand test, based on the measurement of strength in kilogram‐force and the test execution time It is expected to observe a more pronounced reduction in the occurrence of post‐operative complications and hospital stay length in participants of the inspiratory muscle strength training group (IMST) compared to the other groups, verified by means of medical record analysis, based on the counting of days of stay and recording of adverse events