Heart rate variability and heart rate turbulence in patients with chronic obstructive pulmonary disease.

BACKGROUND In chronic obstructive pulmonary disease (COPD) patients, functional and structural changes of the respiratory system greatly influence cardiovascular autonomic functions. Determining autonomic balance may be important in understanding the pathophysiology of COPD and useful clinically in the treatment of COPD patients. Heart rate variability (HRV) and heart rate turbulence (HRT) are useful tools in assessing the autonomic neurovegetative function. Our aim in this study was to evaluate the HRV and HRT variables in COPD patients. Twenty five moderate to severe COPD patients and 25 healthy subjects were included in this study. METHODS Pulmonary function tests and echocardiographic examination, arterial blood gases analysis were performed, HRV and HRT analysis were assessed from a 24-hour Holter recording. RESULTS When HRV and HRT parameters were compared, COPD patients had significantly decreased sNN50 total, pNN50, SDANN, SDNN, SDNNI, rMSDD in time domain HRV parameters, and the values of the HRT onset was significantly less negative in COPD patients. Although the values of the HRT slope were lower in COPD patients, there was no significant difference between the two groups. We also found a correlation between HRT and HRV parameters. CONCLUSIONS In addition to HRV parameters, HRT onset was significantly different in COPD patients. In our opinion, the combination of HRV variables and HRT onset may be simple and elegant ways of evaluating cardiac autonomic functions. New investigations of HRT and HRV in COPD patients have a potential importance for improving risk stratification and therapeutic approaches, and understanding the autonomic outcomes of the disease process.