Purpose: Chronic obstructive pulmonary disease (COPD) is associated with increased incidence of arrhythmias, which has been attributed to autonomic dysregulation. Detection of autonomic function may facilitate stratification of COPD patients with respect to their risk of development of arrhythmias.
Patients and Methods: A total of 151 COPD patients and 45 non-COPD patients were included in this study. Heart rate deceleration runs (DRs) were detected by dynamic electrocardiogram (ECG); DRs successively occurring in 2, 4, or 8 cardiac cycles were denoted as DR₂, DR₄, and DR₈, respectively. Indicators of arrhythmias including isolated premature atrial contractions (PAC), supraventricular tachycardia (SVT), isolated premature ventricular contractions (PVC), and ventricular tachycardia (VT) were recorded. Occurrence of SVT or PAC ≥ 70/day was considered positive for supraventricular arrhythmias, while positive ventricular arrhythmias category (PVAC) was defined as occurrence of VT or PVC ≥ 10/hour.
Results: Compared with non-COPD individuals, COPD patients were associated with increased number of PAC, PVC, higher incidence of PAC > 70/d, SVT, PVAC, and decreased DRs (DR2, DR4, DR8) (P< 0.05). In COPD patients, DRs showed a negative correlation with the incidence of PAC, PVC, SVT, and PVAC (P< 0.05). In receiver operating characteristic curve analysis, all the DRs were found to be significant predictors of PAC > 70/d, SVT, and PVAC. The predictive power of DRs was significantly different from one another with the order ranged as DR4>DR8>DR2 for PAC > 70/d, DR8>DR4>DR2 for SVT, and DR8>DR4>DR2 for PVAC.
Conclusion: Our study provides evidence of significant autonomic dysregulation in COPD patients. DRs may serve as a marker of the risk of arrhythmias in COPD patients.
Keywords: chronic obstructive pulmonary disease, arrhythmias, deceleration capacity runs, autonomic function, risk stratification