Myocardial bridging is a congenital anomaly in which the arteries that feed the muscles of the heart form inside the heart muscle instead of on the outer surface. Thus, the arteries (typically the left anterior descending) are squeezed each time the heart muscle contracts to pump the blood.
In some cases, the amount of constriction or blockage is less than 50 percent and the condition may be harmless. If it is 70 percent or more blocked, it may cause vasospasm, angina (chest pain), arrhythmias, and ventricular tachycardia (racing heartbeat).
This is a serious condition, especially for children with hypertrophic cardiomyopathy.
Where symptoms occur, there are medical treatments, including beta-blockers and calcium-channel blockers. In more severe cases there are surgical options, including “myotomy” (a cutting of the heart muscle to ease the constriction), stenting, and bypass.