DECREASE HEART RATE VARIABILITY IN PATIENTS WITH COPD

Abstract

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of supraventricular and ventricular arrhythmias. PURPOSE: This study was undertaken to test the hypothesis that heart rate variability (HRV), a measure of the autonomic nervous system modulation, is decrease in patients with COPD. METHODS: Seventeen patients (age: 66 ± 7 yrs [mean ± SD], FEV1 = 44 ± 13% pred) and 10 control subjects (age: 63 ± 3 yrs) performed a 24-hr ambulatory blood pressure and a 24-hr Holter monitoring to evaluate HRV. Three time-domain and three frequency domain were studied: standard deviation of normal RR intervals (SDNN), square root of the mean of squared differences between adjacent normal RR intervals (r-MSSD), percentage of differences between adjacent normal RR intervals exceeding 50 milliseconds (p-NN50), very low-frequency power (VLF, 0.01 to 0.04 Hz), low-frequency power (LF, 0.04 to 0.15 Hz), and high-frequency power (HF, 0.15 to 0.40 Hz). RESULTS: Mean resting and 24-hr blood pressure were respectively 142/73 ± 16/10 mmHg, 129/74 ± 10/7 mmHg in patients with COPD and 142/72 ± 18/9 mmHg, 130/76 ± 13/8 mmHg in normal subjects. There was no significant difference between patients with COPD and control subjects in resting and 24-hr blood pressure. However, all HRV indices were reduced in subjects with COPD compared to control subjects. CONCLUSION: Although, the clinical importance of these findings remains to be determined, the decrease in HRV in COPD paired for age and blood pressure may results in increase risk of arrhythmias in this population. Supported by local fond.Table: No Caption Available.