There may also be a shortness of breath or loss of consciousness with the episode. The angina pain may be relieved by a vasodilator drug such as sublingual nitroglycerin which relaxes and opens the coronary artery to allow blood flow to resume. In the event the blood flow stops altogether, this leads to cell death of a segment of the heart muscle supplied by that vessel. Notice how the abnormal coronary artery is severely narrowed. This is called coronary artery disease and myocardial ischemia.
Ischemia is a state of reduced blood flow and oxygen starvation.
If the blood flow becomes severely reduced, the vessel may completely occlude. If complete occlusion happens, then the heart muscle in the area supplied by that vessel will die. This is called myocardial infarction. There is a direct causal relationship between smoking and coronary artery disease. If you are a smoker now, please stop.