LAD (left anterior descending coronary artery) is usually the largest branch of the left main coronary artery which supplies the major portion of the left ventricle. Hence occlusion of the left anterior descending coronary artery (LAD) can cause extension myocardial infarction (heart attack) which can sometimes be fatal. Hence the term widow maker artery for left anterior descending coronary artery. LAD supplies the front region of the left ventricle known as the anterior wall and the interventricular septum (partition between two ventricles. When the LAD is blocked at its origin, the resulting large anterior wall infarction can produce significant loss of pumping function of the heart. Moreover they are also prone for heart rhythm disturbances early and late in the course, which can cause sudden cardiac death.
LMCA: left main coronary artery; LCX: left circumflex coronary artery; LAD: left anterior descending coronary artery; Diag: diagonal branch of left anterior descending coronary artery. There is slight difference in the angulations of the angiographic view of both images. That is why both images look slightly different. It may be noted that LAD is not visible beyond the stump in the first view while the whole length down is visible after stenting, with a good lumen. The procedure involves passing a small guide wire across the obstruction, inflating a balloon across the obstruction, followed by placement of a metallic stent to support the newly created vessel lumen.