Heart attack is defined as death of a portion of the heart muscle because of the development of sudden obstruction to the flow of blood in the artery that supplies oxygen and nutrients to that portion.The heart consists of a mass of muscle that contracts and relaxes periodically to supply blood to various parts of the body. Being a muscle it requires nutrients and oxygen for its function which is supplied by three coronary arteries.
Deposits of cholesterol and calcium occur in the linings of these blood vessels as age advances and in some build up gradually resulting in obstruction to the blood flow. This leads to the symptoms of exertion related chest pain or angina as it is medically known, when the obstruction becomes severe enough to impede the
required increments in blood flow according to the needs of the heart.
Causes and prevention
Coronary artery disease and its most lethal counterpart heart attack or myocardial infarction in medical jargon, is a life style disease. A heart healthy diet consisting of plenty of fruits and vegetables, less of saturated and trans fats, whole grain cereals and nuts along with good physical exercise like brisk walking, jogging, cycling or
swimming for 30 minutes daily at least for 5 days a week should do a lot to prevent this disease. Add to that, avoidance of tobacco, moderation of alcohol and maintenance of ideal body weight, one can conquer this deadly disease to a large extent.
High fat diet, obesity, tobacco and a fast stressful lifestyle on the contrary lead to injury of the lining of the coronary arteries that supply blood to the heart resulting in increased clotting tendency of the blood as well as rupture of a fat rich plaque which in turn leads to the heart attack. Coexisting diseases such as diabetes, hypertension and high cholesterol levels contribute to this.
Extreme levels of stress by itself can sometimes lead to a heart attack, what is known as “broken heart syndrome” or stress cardiomyopathy. In these cases, the coronary arteries have no obstructions but excess production of certain chemicals in the body in response to stress exert their toxic effects on the heart.
Unaccustomed physical exercise can at times lead to a heart attack which is due to sudden injury to the lining of the artery called coronary dissection.
Spontaneous coronary dissections are also known to occur especially in young women of child bearing age leading to heart attacks. Certain viral infections are also known to produce heart attacks secondary to their effects on coronary arteries and heart muscle.
The immediate treatment for heart attack is restoration of the blood flow to the affected area and the most effective method accepted world over as of now is emergency coronary angioplasty which involves directly visualising the blocked artery with the help of x-ray and opening the block with a balloon followed by stenting. This procedure has successfully brought down the death rate and the rate of heart failure which are consequences of a heart attack. Hence the responsibility on the part of the patient is to recognise the pain at the earliest and try to reach a hospital preferably with cathlab facility so that emergency angioplasty can be carried out.
The other effective method of reperfusing the artery is called thrombolysis which involves administration of a drug in to the veins so that it can go to the affected artery and dissolve the obstructing clot thereby re-establishing the blood flow. Once the patient stabilises he can be referred for angiography and angioplasty if needed preferably within 24 hours.
Of course there are various adjunctive drugs to be given along with the above said procedures to maintain the stability of the heart and routinely the patient is kept under observation in the intensive care unit for 24-48 hours.