Dyspnea and Heart Failure: The Role of the Diaphragm.

Introduction: Dyspnea and exertional intolerance are the most common clinical manifestations of Heart Failure (HF). One of the possible mechanisms of both symptoms in HF patients is weakness of the inspiratory muscles.

Aim: Because the diaphragm is the main inspiratory muscle, this review aimed to investigate the contribution of diaphragmatic function to the genesis of dyspnea or exercise intolerance in HF patients.

Methods: Original articles, clinical trials, and cohort or case-control studies published between January 2003 and March 2023 were included. The population, variables, and outcome strategy were the basis of this review, including studies that assessed HF patients, diaphragmatic function, and dyspnea or exercise tolerance. The PubMed/MEDLINE, Embase, and BVS/LILACS databases were searched.

Results and discussion: A total of 353 articles were identified from electronic databases. After removing duplicate articles and screening based on titles, abstracts, and full texts, nine articles were included in the qualitative synthesis of this review. These studies were quite heterogeneous in their methodologies; however, most, except two, demonstrated an association among diaphragmatic dysfunction, dyspnea, and exertional intolerance in HF patients.

Conclusion: Although few studies have assessed the contribution of diaphragmatic function to dyspnea and exertional intolerance in HF individuals, the vast majority of articles included in this review found such an association, especially when diaphragmatic function was assessed using ultrasound.