Factors Associated with Heart Rate Recovery in People with ChronicObstructive Pulmonary Disease: An Analytical Cross-Sectional Study

Introduction: Heart rate recovery (HRR) delay is a marker of cardiac autonomic dysfunction. In people with chronic obstructive pulmonary disease (COPD) attending pulmonary rehabilitation programs, assessing HRR could have prognostic utility, yielding valuable information for setting treatment goals and targets in therapeutic interventions. Therefore, this study aimed to establish the sociodemographic, pulmonary function, and functional aerobic capacity differences in people with COPD with normal and abnormal HRR during the 6-minute walk test (6MWT) and explore factors associated with abnormal HRR. Method: Analytical cross-sectional study. Sociodemographic, anthropometric characteristics, pulmonary function, aerobic capacity, BODE index, and Hospital Anxiety and Depression Scale (HADS) were assessed in COPD patients. An HRR cut-off point of 14 beats or more was used to define HRR delay. Results: Of 128 patients included, 89 (69.5%) showed abnormal HRR. Patients with abnormal HRR were classified with higher overweight/obesity, lower resting SpO2 and lower distance walked, predicted percentage, and estimated VO2 in the 6MWT, with more significant symptoms at one minute after the end of the test (dyspnea and fatigue). In the multivariate regression model adjusted for age, sex, resting heart rate, and FEV1, findings showed that distance walked in the 6MWT (OR 0.994, p-value=0.010), fatigue at 1 minute (OR 2.12, p-value=0.000), and HADS depression domain (OR 0.87, p-value=0.018) are factors associated with HRR. Conclution: In outpatients with COPD, HRR relates to the distance walked in the 6MWT, fatigue, and depression measured with the HADS.