HEART-RATE-VARIABILITY REFLECTS SEVERITY OF COPD IN PIZ ALPHA(1)-ANTITRYPSIN DEFICIENCY

Background: Analysis of heart rate variability (HRV) is a powerful met hod of assessing severity of conditions affecting the autonomic nervou s system. Study objective: To determine if HRV is decreased and if HRV reflects severity in COPD. Design: Prospective determination of HRV f rom 24-h outpatient Hotter recordings. Patients: Eighteen individuals with PiZ alpha(1)-antitrypsin deficiency: 13 with COPD and 5 with norm al FEV1. HRV was also determined in 18 matched normal control subjects . Approximately 3 years after the initial recording, all COPD subjects were contacted to determine current status, Measurements: Indexes of heart rate (HR) and HRV were compared for groups of patients with and without COPD and their control subjects. Results: Mean and minimum HRs were higher in COPD patients. Virtually all indexes of HRV were signi ficantly decreased in COPD patients, No differences were found in IIR or HRV between PiZ individuals with normal FEV1 and their age- and gen der-matched control subjects. Patients who had a change in status (ie, death, lung transplant, listed for transplant) had significantly high er day-time HRs, lower values for HRV indexes reflecting mixed sympath etic and parasympathetic modulation of HR, and reduced daytime high-fr equency spectral power, an index of cardiac vagal modulation. Signific ant correlations (r=0.48 to 0.88) were found between FEV, and these an d other indexes of HRV. Most other indexes of HRV also tended to be lo wer for the group whose status had changed. Conclusion: PiZ alpha(1)-a ntitrypsin deficiency COPD is associated with abnormal cardiac autonom ic modulation. Indexes of HRV appear to reflect severity and may have prognostic value in COPD patients.