ALTERED HEART RATE DYNAMICS AND CIRCADIAN RHYTHM IN PATIENTS WITH COPD AND/OR HEART FAILURE

Abstract

TYPE: Late Breaking Abstract TOPIC: Obstructive Lung Diseases PURPOSE: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) both exhibit time-of-day variations in symptoms. While changes in circadian rhythms (e.g., dipping patterns) have been described with blood pressure, day-night differences in heart rate variability (HRV) have been largely ignored. We aimed to describe heart rate dynamics and circadian patterns in patients with COPD/HF to provide insight into day-night autonomic regulation in cardiopulmonary disease. METHODS: Using 24-hour ECG data from patients with COPD/HF (n=16, mean age 68.4±8.9 years) and healthy controls from the same age range (n=42, mean age 61.6±9.1 years), we examined the profile of heart rate dynamics, day-night differences, and circadian patterns using conventional time/frequency domain HRV indices and multiscale-entropy-based complexity index. RESULTS: 24-hour long-term HRV indices showed significant between-group day-night differences on △LF/HF (-0.3±1.3 in patients vs 1.1±2.5 in controls, p=0.042), suggesting non-dipping or reversed day-night differences in the patient group. Healthy controls had higher complexity compared to patients (1.24±0.12 vs 1.01±0.27, p<0.001) and showed a dipping pattern (1.4 in the day vs 1.1 in the night). However, patients with COPD/HF showed a reverse-dipping pattern (0.9 in the day vs 1.3 in the night), suggesting non-restorative cardiopulmonary function at night. CONCLUSIONS: Day-night differences and circadian patterns of heart rate dynamics are altered in patients with COPD/HF, similar to blood pressure patterns indicating clinically relevant autonomic dysregulation. CLINICAL IMPLICATIONS: Circadian patterns of HRV and complexity may be of potential importance in informing risk stratification and therapeutic considerations in cardiopulmonary disease. DISCLOSURE: We would like to acknowledge the support from the National Institutes of Health (NCCIH T32AT000051, K24AT009465, K24AT009282). Dr. Peter Wayne is the founder and sole owner of the Tree of Life Tai Chi Center. Dr. Wayne's interests were reviewed and manage KEYWORD: cardiopulmonary dysregulation