left anterior descending artery

The left anterior descending artery, usually shortened to the LAD, is the single most important coronary artery — so vital that it has earned the grim nickname the widow-maker when it blocks suddenly.

It is a major branch of the left coronary artery that runs down the front of the heart, along the groove over the interventricular septum. From there it supplies the front wall of the left ventricle and most of the septum — a large and crucial territory of heart muscle.

Because it feeds such an important region, a blockage of the LAD can damage a large amount of the left ventricle and seriously impair the heart's pumping. On an electrocardiogram, an LAD-related heart attack typically shows changes in the chest leads facing the front of the heart, and prompt reopening of the artery is a medical emergency.