Autonomic Influences Related to Early Repolarization in Patients Without Structural Heart Disease.

This cross-sectional study focused on the association between heart rate variability (HRV) and early repolarization pattern (ERP). It included 1236 patients categorized into three groups: ERP type 1: J-point elevation with notched/slurred QRS; ERP type 2: ST elevation without dominant J-wave; and non-ERP group. Analyzing time-domain indexes include standard deviation of NN (normal-to-normal) RR intervals (SDNN), root mean square of successive difference in NN RR intervals (RMSSD), and proportion of consecutive NN intervals that differ by more than 50 ms (PNN50), there were significant differences between any two groups (all P ERP type 1 > non-ERP. Multivariate logistic regression analysis revealed that SDNN at nighttime and gender were independently associated with the maximum magnitude of J-point elevation ≧ 0.2 mV. The findings strongly suggested that based on electrocardiogram characteristics, parasympathetic tone denoted by HRV may be related to different types of ERP.