Influence of long-term oxygen therapy on cardiac acceleration and deceleration capacity in hypoxic patients with chronic obstructive pulmonary disease

Summary Background: There is increasing interest in cardiovascular co‐morbidities of chronic obstructive pulmonary disease (COPD). Heart rate turbulence (HRT) and phase‐rectified signal averaging (PRSA) techniques quantify the heart’s acceleration/deceleration capacities. We postulated that these methods can help assess the integrity of cardiac control in hypoxic COPD. Methods: Eight hypoxic stable COPD patients, nine healthy age‐matched older adults and eight healthy young adults underwent ECG monitoring for 24 h. Patients with COPD were also monitored following 4 weeks of standardized oxygen therapy. HRT measures [turbulence onset (TO), turbulence slope (TS)] and PRSA‐derived acceleration/deceleration (AC, DC) indices were quantified within 6‐h blocks to assess circadian variation. Results: There were between‐group differences for variables TS, DC and AC (P