Bridge of the left anterior descending artery revealed by syncope: a case report

The myocardial bridge is a congenital coronary anomaly defined as the presence of a region of myocardium overlying an epicardial coronary artery. This is a 51-year-old patient, diabetic for 4 years on oral hypoglycemic, has had stress angina for 4 years, neglected by the patient. The current history goes back to 2 months by the installation of an episode of syncope occurring with the effort, then of a second episode the day of its admission. Electrocardiogram on admission showed complete atrioventricular block with an heart rate of 32 beats per minute, the patient spontaneously recovered sinus rhythm with a heart rate of 88 beats per minute and a PR interval of 200 ms, coronary angiography was performed showing coronary arteries without stenosis with an intramyocardial bridge of the left anterior descending artery. During exercise and in the presence of a myocardial bridge on the left anterior descending artery, systolic compression leads to a decrease in flow to the septal branches, which is responsible for an alteration of the vascularization of the sub-nodal tissue with paroxysmal conduction disorders leading to syncope. Conduction disorders of ischemic origin are not always associated with atherosclerotic or thromboembolic lesions, but may also be secondary to myocardial bridges.