Análise da força muscular respiratória e qualidade de vida em pacientes com insuficiência cardíaca crônica em Macapá

Abstract

Heart failure (HF) is characterized by the incapacity of the heart to provide the metabolic needs of the body through progressive and persistent reduction of blood flow, which can cause peripheral and respiratory muscle changes, resulting in symptoms such as dyspnea, fatigue and exercise intolerance, which can lead to a worse quality of life. Objectives: To analyze respiratory muscle strength and quality of life in patients with HF. Methodology: This is a cross-sectional study, which included outpatients with a medical diagnosis of compensated HF, of both genders and aged 18 years or older. Respiratory muscle strength was assessed by means of a manovacuometer, through the measurements of maximal inspiratory and expiratory pressures (PImax and PEmax). To assess quality of life, the Minnesota Living With Heart Failure Questionnaire (MLHFQ) was applied, consisting of 21 items arranged in physical, emotional, and general dimensions, with a total score ranging from 0 to 105, where higher values reflect a worse quality of life. All data were analyzed using the software Statistica 10.0, and described by mean, confidence interval (95%), and frequencies. Student's t test, Pearson's correlation and one-way analysis of variance followed by Tukey's post-hoc test was used, considering a 5% significance level. Results: Sixty-three patients (66.6% men) were included, with a mean age of 62.0 years, ejection fraction (EF) of 42.0%, the majority being in New York Heart Association (NYHA) functional class II (55.1%), followed by NYHA III (23.3%). There was a predominance of ischemic etiology (36.7%), followed by idiopathic (25.0%), valve (23.3%) and dilated (15.0%). Respiratory muscle strength was within normal range, with values above 70% of predicted [%Pmax=81.4% (75.3-87.4%); and %PEmax=94.9% (88.6-101.2%)]. A small proportion of patients of dilated etiology presented lower PImax values, compared to those of ischemic etiology (p=0.01). The mean value obtained in the MLHFQ total score was 44.4 points (38.95-50.03). Patients with NYHA III had higher scores in the total score (p<0.01) and physical dimension (p<0.01), when compared to NYHA I and II. Patients with disease time greater than 120 months also had higher scores in the physical (p<0.01) and emotional (p=0.04) dimensions. The %FE correlated negatively with the MLHFQ total score (r= -0.29; p=0.02), physical dimension (r= -0.28, p=0.03) and overall dimension (r= -0.31, p<0.01). Moreover, there was also a weak correlation between the general dimension and age (r= -0.29, p=0.02). Conclusions: Patients with HF had preserved respiratory muscle strength, but those with dilated HF had lower PImax values. The quality of life was moderately compromised, where the increased time of disease, NYHA III and lower EF influenced the higher scores of the MLHFQ.