The Cardiovascular System with the heart at its centre, is responsible for the blood supply that is essential for every part of the body. To pump the blood through the blood vessels, the heart has to contract from about 60 times a minute under normal conditions upto double or thrice the number under stress conditions. There are various factors which can disturb the right functioning of the heart:
Congenital heart defects
Cardiomyopathy "weak heart"
Failure of the electrical stimulation system
Insufficiency or stenosis of valves and many others
Here we deal only with the diseases which are the results of a diminished blood supply of the heart itself. As any other muscle, the heart must be supplied with sufficient amount of oxygen and other substances. Under certain conditions because the walls of the arteries of the heart (Coronary arteries) become occluded. This is called arteriosclerosis. Occlusion leads to reduced blood supply, damage of muscular tissue (causing the typical pain) and reduced heart function.
The end result this partial or complete occlusion (clogging) of the coronary arteries is an ischaemic damage to the heart muscle and may manifest as anginal pains on exertion and/or at rest. However, if the coronary occlusion is very severe, and if the blood flow ceases for a prolonged period, the area of the heart muscle supplied by the affected coronary artery can become dead resulting in a myocardial infarction (commonly called "heart attack")
- Angina pectoris: Patient may present with a typical pain behind the sternum or either side of the chest, radiating down the arm (normally left arm) or at the angle of the jaw. Characteristically the pain may be more of a heaviness, tightness, choking or constricting sensation. The pain usually lasts for a few minutes. The pain may be precipitated by brisk walking, climbing or heavy meals and relieved by rest or the use of sublingual tablet (Nitroglycerine). An entity called unstable angina is suspected when the above symptoms appear even at rest and do not respond to the usual medication. This is a more severe condition.
- Myocardial infarction (Heart attack): Here the patient usually presents severe chest pain lasting for a longer period even upto an hour or more. He may even suffer from certain complications like fall in blood pressure or disturbance of heart rhythm or conduction. Hence immediate medical attention is required and the patient should be shifted to the nearest hospital or preferably an intensive care unit.
- Angina: Treatment is primarily medical mainly to relieve symptoms. However, in certain circumstances when medical treatment fails or at the doctor’s discretion, coronary by-pass surgery may be contemplated.
- Myocardial infarction : This is an emergency situation and the patient should be observed and treated in the intensive care unit.
- Prevention: Elimination of risk factors.
- Male sex
- Age over 50
- Diet rich in fat and cholesterol
- Physical inactivity
- Genetic disposition