The Role of the Ratio of J-Point Elevation Magnitude and R-Wave Amplitude on the Same ECG Lead in the Risk Stratification of Subjects With Early Repolarization Pattern.

ABSTRACT

BACKGROUND: Just as high-risk populations for cardiac arrest exist in patients with Brugada syndrome or long QT syndrome, high-risk and low-risk populations for cardiac arrest also exist in patients with early repolarization pattern (ERP). HYPOTHESIS: Electrocardiographic (ECG) characteristics can aid the risk stratification of patients with ERP. METHODS: Electrocardiographic parameters such as magnitude of J-point elevation and J/R ratio were measured. The magnitude of J-point elevation, leads with J points elevated, J/R ratio, morphology of the ST segment, and QT/QTc interval were used in comparative analysis in 2 groups 57 patients with ERP and cardiac arrest (cardiac arrest group) and 100 patients with ERP but without cardiac arrest (control group). RESULTS: There was no statistical difference in clinical characteristics of the 2 groups. The J/R ratio in the cardiac arrest group was significantly higher than in the control group (26.8% ± 18.1% vs 16.3% ± 10.3%, respectively; P < 0.001) and the proportion of horizontal/descending ST segments (70.2%) was significantly higher than in the control group (29.0%), but the proportion of ascending/upsloping ST segments (29.8%) was significantly lower than in the control group (71.0%; P < 0.001). Multivariate logistic regression revealed that higher J/R ratio and horizontal/descending ST segment were independently associated with increased risk of cardiac arrest in patients with ERP. CONCLUSIONS: In patients with ERP and cardiac arrest, J/R ratios were relatively higher and mostly with horizontal/descending ST segments, suggesting that J/R ratio and ST-segment morphology may be used as indicators for risk stratification in patients with ERP.