Effect of percutaneous transluminal coronary angioplasty on heart rate variability and left ventricular functions in patients with coronary artery disease

ABSTRACT Effects of Percutaneous Transluminal Coronary Angioplasty on Heart Rate Variability and Left Ventricular Functions in Patients with Coronary Artery Disease Autonomic nervous system dysfunction and reduced heart rate variability (HRV) after percutaneous transluminal angioplasty (PTCA) were reported in patients with coronary artery disease. However, factors related to reduced HRV are not clearly demonstrated. The aim of the present study was to assess the relationship between clinical features, left ventricular catheterization findings, PTCA results and HRV indexes after successful PTCA. Seventy-two patients (62 male, 10 female, mean age: 52.4+7.8 years) with coronary artery disease entered the study. PTCA was performed in all patients. Low- frequency power (LFP), high frequency power (HFP) and total power (TP) were calculated by using frequency-domain method for HRV. Left ventricular (LV) systolic and diastolic functions were examined by two-dimensional and Doppler echocardiography. All examinations were performed before PTCA, and twenty-four hours, ten days and thirty days after PTCA. The patients were divided into two groups according to the number of stenotic coronary artery; patients with single- vessel disease which PTCA performed to single lesion (Group I) and patients with multi-vessel disease which PTCA performed to multiple lesions (Group II). The groups were comparable for age, gender and coronary artery risk factors. HRV was found to be reduced in group I and II after PTCA. Reduction of HRV was more significant in group I than group II (p<0.05). Reduction in HRV after PTCA was significantly related to revascularization degree (r=0.50, p=0.008). The relation between the reduction in HRV and presence of previous myocardial infarction and LV contractile dysfunction were found to be statistically significant in group II (r=0.51, p=0.07 and r=0.43, p=0.02). Recovery of HRV occurred on the 10th day after PTCA in group I, on the 30th day of PTCA in group II. Although impaired LV diastolic function found after PTCA, systolic function improved in two groups. Recovery of diastolic function was observed on the 10th day of PTCA. In conclusion, transient and rapidly recovered, especially parasympathetic modulated HRV reduction after PTCA is a result of reperfusion in patients with single- vessel disease. HRV reduction in patients with multi-vessel disease is a consequence of previous myocardial infarction and LV contractile dysfunction. Key Words: Heart rate variability, left ventricular functions, percutaneous transluminal coronary angioplasty VI