Impact of inspiratory muscle training on respiratory muscle function and functional capacity in patients with heart failure: a scoping review

Heart failure (HF) is one of the most prevalent diseases in the world and is characterized as a complex clinical syndrome. It is a disease that affects both the peripheral muscles and the respiratory muscles, causing damage such as reduced strength and endurance. One of the main symptoms is fatigue and exercise intolerance. The aim of this review article is to assess whether the use of inspiratory muscle training (IMT) associated with conventional training enhances inspiratory muscle strength (PImax) and inspiratory muscle endurance (SPImax) and functional capacity in patients with HF. Methods: A literature review was carried out on the use of IMT in patients, including 6 randomized clinical trials, searched in the PubMed, PEDro and Lilacs databases. Results: There is evidence showing an increase in PImax and SPImax with the addition of IMT to training; in addition, an improvement in VO2 peak, circulatory power and ventilatory efficiency. Conclusion: The use of IMT associated with conventional training is an interesting strategy for boosting gains in strength and inspiratory muscle endurance, increasing exercise tolerance and consequently improving patients' quality of life. However, more studies are needed in order to more clearly define the selection criteria and methodology for applying IMT.