Abstract / Summary
Background: Heart rate variability (HRV) provides insights beyond standard electrocardiography (ECG). Although prior studies have shown altered short-term linear HRV in patients with paroxysmal atrial fibrillation (PAF) after pulmonary vein isolation (PVI), long-term nonlinear changes are unclear. This study aimed to investigate longitudinal nonlinear HRV changes before and after PVI in PAF patients.
Methods: Forty-two drug-refractory PAF patients (55.50 ± 9.53 years old, 11 females) undergoing PVI were enrolled. Holter ECG was recorded before, at 1-3 months, and at 6-12 months post-PVI. Nonlinear HRV variables including multi-scale entropy (MSE), detrended fluctuation analysis (DFA), and Poincaré plot analysis, were analyzed.
Results: Significant reductions in standard deviation (SD)1, SD1/SD2, MSE 1-5, and MSE 6-20 were found 6-12 months post-PVI compared to baseline. SD2, MSE slope 5, and DFA slope 1 decreased at 1-3 months post-PVI but showed significant increases at 6-12 months post-PVI. DFA slope 2 increased significantly after PVI.
Conclusions: Long-term fractal correlation properties (DFA slope 2) increased significantly following PVI. Heart rate complexity (MSE 1-5 and MSE 6-20) and vagal activity (SD1) decreased significantly after PVI, whereas short-term fractal correlation properties (DFA slope 1) and short-term heart rate complexity dynamics (MSE slope 5) decreased at 1-3 months post-PVI and then increased by 6-12 months post-PVI. These results highlight the significant and varied effects of PVI on cardiac neuromodulation and complexity, as demonstrated by HRV parameters.