Depicts progressive coronary artery disease of the heart, showing normal blood flow throught the left main coronary artery contrasted with a blocked version with 95% occlusion. The left anterior descending (LAD) branch of the left coronary artery is called the &quot;Artery of Sudden Death&quot; because it supplies the left ventricle heart muscle. When the LAD is suddenly occluded, a fatal myocardial infarction, or heart attack, usually occurs.