What is Heart Attack

Heart Attack can also be called myocardial infaction or cardiac infaction. Heart Attack simply means the infarction of a segment of the heart muscle, usually as a result of occlusion of a coronary artery.

Heart attack occurs when blood flow to a section or part of the  heart muscle becomes blocked or occluded. If the flow of blood to that part of the heart muscle isn’t restored quickly, the section of heart muscle affected becomes damaged from lack of oxygen.

According to Wikipedia, Heart Attack occurs when the blood supply to part of the heart is interrupted causing some heart cells to die. This is most commonly due to occlusion (blockage) of a coronary artery following the rupture of a vulnerable atherosclerotic plaque, which is an unstable collection of lipids (like cholesterol) and white blood cells (especially macrophages) in the wall of an artery. The resulting ischemia (restriction in blood supply) and oxygen shortage, if left untreated for a sufficient period of time, can cause damage and / or death (infarction) of heart muscle tissue (myocardium).

According to National Institute for Health, “Heart attack is a leading killer of both men and women in the United States”. But fortunately, today there are excellent treatments for heart attack that can save lives and prevent disabilities. Treatment is most effective when started within 1 hour of the beginning of symptoms.

The National Institute of Health also reported that each year, about 1.1 million people in the United States have heart attacks, and almost half of them die. CAD, which often results in a heart attack, is the leading killer of both men and women in the United States.

Many more people could recover from heart attacks if they got help faster. Of the people who die from heart attacks, about half die within an hour of the first symptoms and before they reach the hospital.

Below is a diagram to illustrate what happens during heart attack

Source: National Health Institue

Heart Attack or Myocardial infarction is the most common cause of death in the U.S. About 800,000 people annually sustain first heart attacks, with a mortality rate of 30%, and 450,000 people sustain recurrent heart attacks, with a mortality rate of 50%. The most common cause of Hearth Attack or Myocardial Infarction  thrombosis of an atherosclerotic coronary artery. Less common causes are coronary artery anomalies, vasculitis, or spasm induced by cocaine, ergot derivatives, or other agents. Risk factors for Heart Attack or Myocardial Infaction  include male gender, family history of Heat Attack, obesity, hypertension, cigarette smoking, and elevation of total cholesterol, LDL cholesterol, homocysteine, lipoprotein (a), or C-reactive protein. At least 80% of Heart Attack or Myocardial Infaction occur in people without a prior history of angina pectoris, and 20% heat attack  are not recognized, either because they cause no symptoms (silent infarction) or because symptoms are attributed to other causes. Some 20% of people sustaining  Heart Attack (Myocardial Infaction) die before reaching a hospital. The classical symptom of  Heart Attack  is crushing anterior chest pain radiating into the neck, shoulder, or arm, lasting more than 30 minutes, and not relieved by nitroglycerin; typically pain is accompanied by dyspnea, diaphoresis, weakness, and nausea. Significant physical findings, often absent, include an atrial gallop rhythm (4th heart sound) and a pericardial friction rub. The electrocardiogram shows ST segment elevation (later changing to depression) and T wave inversion in leads reflecting the area of infarction. Q waves indicate transmural damage and a poorer prognosis. Diagnosis is supported by acute elevation in serum levels of myoglobin, lactic dehydrogenase, the MB isoenzyme of creatine kinase, and troponins. Unequivocal evidence of MI may be lacking during the first 6 hours in as many as 50% of patients. Death from acute Heat Attack (Myocardial Infaction) is usually due to arrhythmia (ventricular fibrillation or asystole), shock (forward failure), congestive heart failure, or papillary muscle rupture. Other grave complications, which may occur during convalescence, include cardiorrhexis, ventricular aneurysm, and mural thrombus. Acute Heart Attack (Myocardial Infaction) is treated (ideally under continuous ECG monitoring in the intensive care or coronary care unit of a hospital) with narcotic analgesics, oxygen by inhalation, intravenous administration of a thrombolytic agent, antiarrhythmic agents when indicated, and usually anticoagulants (aspirin, heparin), beta-blockers, and ACE inhibitors. Patients with evidence of persistent ischemia require angiography and may be candidates for balloon angioplasty. Data from the Framingham Heart Study show that a higher percentage of acute Heart Attacks (Myiocardial Infaction) are silent or unrecognized in women and the elderly. Several studies have shown that women and the elderly tend to wait longer before seeking medical care after the onset of acute coronary symptoms than men and younger persons. In addition, women seeking emergency treatment for symptoms suggestive of acute coronary disease are less likely than men with similar symptoms to be admitted for evaluation, and women are less frequently referred than are men for diagnostic tests such as coronary angiography. Other studies have shown important gender differences in the presenting symptoms and medical recognition of MI. Chest pain is the most common symptom reported by both men and women, but men are more likely to complain of diaphoresis, while women are more likely to experience neck, jaw, or back pain, nausea, vomiting, dyspnea, or cardiac failure, in addition to chest pain. The incidence rates of acute pulmonary edema and cardiogenic shock in Heart Attack are higher in women, and mortality rates at 28 days and 6 months are also higher. – adapted from Steadman Medical Dictionary