An acute myocardial infarction (AMI) or a heart attack is the result of interruption in blood flow to the heart. Without a supply of blood and the oxygen dissolved in it, the myocardium or heart muscle supplied by the occluded vessel starts to die. Immediate treatment however can restore blood flow and prevent further damage to the heart. Atherosclerosis (or the process of cholesterol deposition on the walls of the coronary arteries to form plaques) is by far the most common underlying cause of ischemic heart disease (including myocardial infarctions). This process of plaque buildup in the coronary arteries is called coronary artery disease, or CAD. In many people, plaque begins to form in childhood and gradually builds up over a lifetime.  However atherosclerosis alone is not fatal. The life-threatening complications of atherosclerosis, including ACS (or acute coronary syndrome) and AMI, are precipitated by disruption (or breaking open) of the cholesterol laden plaque (or deposit) on which thrombosis or clot formation is superimposed, causing a critical reduction in blood flow.  In rare cases AMI have a nonatherosclerotic cause such as trauma, arteritis or inflammation of the arteries, dissections or tears of the blood vessel lining, embolism or as a complication of cardiac catheterization. Although intense exercise, strenuous activities, emotional stress, or illegal drug use can trigger an AMI, in a majority of cases it is not clear what triggers a heart attack.
The classic symptom of a heart attack is chest pain or discomfort. The pain is described as discomfort, pressure, squeezing, or heaviness in the chest. The pain may spread down the shoulder and arm or to other areas, such as the back, jaw, neck Patients often put their fist to their chest when describing the pain, a finding referred to as the Levine’s sign.
Abraham Salacata, MD, FACC