Functional class and type of pulmonary hypertension determinate severity

Objective Heart rate variability (HRV) and turbulence (HRT) are validated methods of evaluation of cardiac autonomic nervous system (cANS) dysfunction which is associated with sudden cardiac death. There is limited data on cANS imbalance and its signifi cance in patients with pulmonary hypertension (PH), so we assessed HRV and especially HRT alterations in PH.Methods and results Thirty-three out of 41 PH patients were enrolled in the study: 22 (66.7%) with pulmonary arterial hypertension (PAH) and 11 (33.3%) with chronic thromboembolic PH (CTEPH), 11 patients were in World Health Organization Functional Class (WHO-FC) I-II, and 22 others in WHO-FC III-IV. The control group consisted of 25 healthy persons. Routine evaluations, echocardiography, right heart catheterization and 24-hour Holter monitoring with time-domain HRV and HRT evaluation were performed. Most of HRV indices and both of HRT parameters were signifi cantly impaired in PH patients, as compared to control subjects. Abnormal HRT (turbulence on...