Frequency and Factors Associated with Early Repolarization Changes in ECG in Patients Presenting With Chest Pain

Objectives: The “early repolarization (ER)” pattern, previously regarded as benign, has recently shown associations with adverse outcomes, including all-cause, arrhythmic and cardiac mortality. This study aimed to assess the prevalence and factors linked to ER changes in the ECG among chest pain patients at a tertiary cardiac center. Methodology: We enrolled 271 patients aged 18-80 with chest pain complaints. Baseline 12-lead ECGs were used to assess the ER pattern. Multivariable binary logistic regression was conducted, and “odds ratios (OR)” with 95% “confidence intervals (CI)” were reported. Results: Of the 271 patients, 162 (59.8%) were male, with a mean age of 55.3 ± 10 years, and 40 (14.8%) were ≤45 years old. The ER pattern was present in 92 (33.9%) patients. The ER pattern was associated with low “body mass index (BMI)” (OR=0.85 [95% CI: 0.77 - 0.94; p=0.002]), shorter T-wave duration (OR=0.99 [95% CI: 0.98 - 1.00; p=0.008]), and lower heart rate (OR=0.94 [95% CI: 0.90 - 0.98; p=0.007]). Additionally, the odds of ER pattern were lower in patients with “ST-elevation myocardial infarction (STEMI)” (OR=0.23 [95% CI: 0.07 - 0.72; p=0.012]) and non-STEMI (OR=0.21 [95% CI: 0.07 - 0.63; p=0.006]) compared to non-cardiac chest pain. Conclusion: Early repolarization is a common ECG pattern in one-third of chest pain patients. Associated factors include low BMI, shorter T-wave duration, and lower heart rate, and it is less frequent in patients with STEMI and non-STEMI.