Avaliação da modulação autonômica cardíaca no teste de caminhada de seis minutos e da qualidade de vida na insuficiência cardíaca

Abstract

Purpose: To evaluate and characterize the heart rate variability (HRV) during a six-minute walk test (6MWT) in chronic heart failure patients (CHF) on beta-blocker treatment and analyze their quality of life (QOL) through appropriate questionnaires. Methods: Seventeen volunteers were divided into two groups: CHF group (CHFG, n=7, 47±14.9 years old) and control group (CG, n=10, 55±12.9 years old). The participants performed two 6MWT with a 20 minute interval and the RR interval was recorded, beat to beat, for HRV analysis by linear and nonlinear methods. Were assessed the 36-item Short-Form Health Survey (SF-36) in both groups and the Minnesota Living with Heart Failure Questionnaire (MLHFQ) in CHFG. The Mann-Whitney test, Spearman correlation and covariance analysis were used in the statistical analysis. Results: During the 6MWT, the CHFG showed greater complexity of HRV (p<0.03) compared to CG. In the assessment of QoL by SF-36 no statistical significance was found between the groups. Conclusions: The CHFG showed greater complexity of HRV during the 6MWT and a similar performance to the CG during submaximal exercise. Registration clinicaltrials.gov: NCT01736137