Glossary under construction

Angina – chest pain and/or discomfort caused by insufficient oxygen-rich blood

Atherosclerosis - hardening and thickening of arteries usually caused by cholesterol, calcium, fibrin, and AGEs (Advanced Glycation End Products

Coronary artery disease (CAD) – narrowing and/or blockage of the arteries, usually caused by atherosclerosis

Depth of myocardial bridge – see halo

dFFR - Diastolic fractional flow reserve -

Endothelial dysfunction (ED) – dysfunction of the inner lining of the artery i.e. the endothelium, causing the artery not to be able to dilate properly to let blood through. MBs tend to cause ED, especially as one gets older. Stanford believes that the sheer pounding that the coronary artery takes being squeezed under a band of muscle in a MB causes endothelial dysfunction in the MB area, and that this worsens with age. Patients who are able to identify MBs early and get unroofing surgery are much less likely to develop ED.

FFR - Fractional Flow Reserve

Halo - the half-moon shaped band of muscle that lies over the MB. Its thickness gives you the depth of the MB. So for example a halo of 1 mm means the MB depth is 1 mm. Even a halo <1 mm can cause major symptoms. Some people with very deep MBs have halo of 4+ mm.


Ischemia – restriction of blood supply to tissues that causes a lack of oxygen

Jailed arteries - septal coronary arteries stuck inside the the MB so that, along with the LAD, they are also squeezed when the MB is compressed. This prevents blood from reaching the center of the heart.

Junk diagnosis/wastebasket diagnosis – fake and usually vague diagnosis by a doctor. Anxiety is a common junk diagnosis for myocardial bridges. MB patients often have received fake diagnoses for years before finding out the real cause of their symptoms is the MB.

LAD – left anterior descending artery. Most important artery to the heart

LCX – left circumflex artery. A second coronary on the left side of the heart that wraps around in a curve.

PVC – premature ventricular contractions, abnormal extra heartbeats which can make you feel palpitations or a skipped beat

RCA – right coronary artery. Main artery supplying blood to the right side of the heart


Septal coronary arteries - the smaller arteries that branch off the main coronary arteries (like the LAD) and carry blood into the center of the heart, called the septum. They branch off either side toward the interior of the body.

Septal buckling – buckling of the septum due to ischemia i.e. lack of oxygen, which often happens in MB patients during the Stress Echocardiogram test. The septum is part of the heart muscle, the thick inner divider between right and left sides. Stanford uses septal buckling as proof of ischemia so there can be no doubt that symptoms were occurring.

Vasospasm – In MBs, vasospasm occur when the coronary artery becomes suddenly temporarily tightened and constricted causing a complete or near-complete blockage of the artery. The result is often deep and sometimes crushing angina (chest pain) that can radiate down the arm.

Examples of MB “maps” from Stanford
S= Septal artery starting point     D = Diagonal artery starting point

Halo = thickness of the muscle band / aka the depth of the MB