Myocardial Bridge Anatomical Characteristics Relationship with ECG Changes and Markers

Background The clinical significance of coronary Myocardial Bridge (MB) anatomical characteristics is controversial in the literature. It is not clear whether MB has a benign or malignant clinical outcome. Objectives To investigate the possible relationship between MB characteristics (depth, length and volume index) with ECG markers [T Peak-to-End interval (Tp-e), transmural dispersion of repolarization and Index of Cardiac Electrical Balance (iCEB)] and changes (ST-T and S/R ratio changes in V1 and aVL leads). Patients and Methods Forty-one patients who were diagnosed as having MB at multi-detector CT exam were enrolled in the study. Results MB depth and volume index were associated with notched QRS ( p = 0.001 and 0.003 respectively) in the whole sample. The association of notched QRS with MB depth and volume index was more significant in patients with coronary atherosclerosis ( p = 0.001 and 0.01 respectively). There was a statistically significant association between MB length ( p = 0.006) and volume index ( p = 0.001) with an increased S/R ratio in aVL lead in patients free from coronary atherosclerosis. No statistically significant association was observed between MB anatomical characteristics with ECG markers of increased arrhythmia ( p > 0.01), including TDR, Tp-e and iCEB. Conclusion MB depth and volume index showed a statistically significant association with notched QRS, particularly in patients with coronary atherosclerosis.