Effect of the final coronary arterial diameter after coronary angioplasty on heart rate variability responses.

Background: Autonomic nervous system dysfunction and reduced heart rate variability (HRV) after percutaneous transluminal coronary 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 HRV indices and the final coronary arterial luminal diameter after PTCA.

Methods: Twenty-seven patients (23 male, 4 female, mean age: 52.5 +/- 7.1 years) with single vessel disease were included in 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 analysis of HRV. All examinations were performed 24 hours before, and 24 hours, 10 days, and 30 days after PTCA. The patients were divided into groups according to the PTCA restenosis risk score, the degree of dilatation, and revascularization after coronary angioplasty.

Results: The groups were comparable for age, gender, and coronary artery risk factors. HRV was found to be reduced in 76% of patients. Reduction in HRV after PTCA was significantly related to the PTCA risk score and the degree of revascularization (r = 0.48, P < 0.01 and r = 0.50, P < 0.008). Reduction in HRV was more significant in patients with previous myocardial infarction (P < 0.05). Recovery of HRV occurred on the tenth day after PTCA.

Conclusion: Transient and rapidly recovered, especially parasympathetically modulated HRV reduction occurred after PTCA in patients with single-vessel disease. HRV reduction is associated with PTCA restenosis risk score and the degree of revascularization as invasive feature of angioplasty, hence it may be related to reperfusion.