Myocardial bridge

Myocardial bridge is a congenital heart defect where one of the coronary arteries, specifically the left anterior descending artery (LAD), is tunneled through the myocardium rather than resting on top of it. This condition is present from birth and is typically harmless, but in some cases, it can lead to serious heart conditions.

Anatomy

In a normal heart, the coronary arteries rest on top of the heart muscle and feed it with blood. In a heart with a myocardial bridge, a segment of one of these arteries, usually the LAD, tunnels through the myocardium (the heart muscle). This tunneling artery is referred to as a "bridged" artery.

Epidemiology

Myocardial bridges are found in about 25% of hearts, making them a common anatomical variant. However, they are often undiagnosed because they typically do not cause symptoms or health problems. They are usually discovered incidentally during a coronary angiogram or at autopsy.

Symptoms and complications

Most people with a myocardial bridge do not experience symptoms. However, in some cases, the condition can cause angina, arrhythmias, or myocardial infarction. These symptoms are thought to occur because the bridged artery can be compressed during heart contraction, reducing blood flow to the heart muscle.

Diagnosis

Myocardial bridges can be difficult to diagnose because they often do not cause symptoms. They may be discovered incidentally during a coronary angiogram, a procedure that uses dye and special X-rays to show the insides of coronary arteries. Other diagnostic methods include computed tomography (CT) angiography and magnetic resonance imaging (MRI).

Treatment

Treatment for a myocardial bridge depends on the severity of the symptoms. If the condition is not causing symptoms, treatment may not be necessary. If symptoms are present, treatment options include medication to lower heart rate and blood pressure, thereby reducing the force of the heart's contractions. In severe cases, surgery may be necessary to unroof the bridged artery.

See also

• Coronary artery disease
• Congenital heart defect
• Angina