High prevalence and clinical implication of myocardial bridging in patients with early repolarization

Purpose: Recent evidence suggests that early repolarization (ER) is related with myocardial ischemia. Compression of coronary artery by a myocardial bridging (MB) can be associated with clinical manifestations of myocardial ischemia. This study aimed to evaluate the associations of MB in patients with ER. Materials and Methods: In consecutive patients (n=1303, age, 61±12 years) who had undergone coronary angiography, we assessed the prevalence and prognostic implication of MB in those with ER (n=142) and those without ER (n=1161). Results: MB was observed in 54 (38%) and 196 (17%) patients in ER and no-ER groups (p<0.001). In multivariate analysis, MB was independently associated with ER (odd ratio: 2.9, 95% confidence interval: 1.98-4.24, p<0.001). Notched type ER was more frequently observed in MB involving the mid portion of left anterior descending coronary artery (LAD) (69.8% vs. 30.2%, p=0.03). Cardiac event was observed in nine (6.3%) and 22 (1.9%) subjects with and without ER, respectively. MB was more frequently observed in sudden death patients with ER (2 out of 9, 22%) than in those without ER (0 out of 22). Conclusion: MB was independently associated with ER in patients without out structural heart disease who underwent coronary angiography. Notched type ER was closely related with MB involving the mid portion of the LAD. Among patients who had experienced cardiac events, a higher prevalence of MB was observed in patients with ER than those without ER. Further prospective studies on the prognosis of MB in ER patients are required.