Relationship between myocardial bridges and arrhythmic complications.

Myocardial bridge (MB) is defined as compression of coronary artery during systole while it is normal in diastole. In angiographic series, the prevalence of this anomaly was reported between 0.5% and 2.5%. It is occasionally seen in the middle segment of the left anterior descending coronary artery. Although MB is considered to be a benign anomaly, the association of MB with ischemia, systolic dysfunction, conduction abnormality, arrhythmias, and sudden cardiac death were reported. Herein, we report 3 cases of MB that were diagnosed with coronary angiography and were associated with arrhythmic complications. In 2 patients, complete atrioventricular block was present, and another patient was diagnosed with sick sinus syndrome with the help of an electrophysiological study. All patients underwent permanent cardiac pacemaker implantation.