The heart is a cone shaped muscular organ which lies underneath the breast bone, more to the left side. The function of your heart is to pump blood through about 96,000 km of blood vessels distributing blood from head to toe. Your heart beats about 60-120 per minute depending on your activities. It pumps at a rate of about 5 litres a minute.
For this amazing function of the heart, it requires its own blood supply to provide energy. The blood is distributed to the heart muscles by arteries (blood vessels) called coronary arteries. Narrowing or blockage of these arteries results in ischaemic heart disease or coronary artery disease. The narrowing of the arteries is brought about by deposition of cholesterol within the wall of the arteries.
The coronary artery disease manifests as angina, myocardial infarction (heart attack) or as silent heart attack.
1) Angina Pectoris manifests as chest discomfort or tightness which may radiate to neck or down the left arm on exertion such as during brisk walking or walking uphill. The discomfort disappears on stopping the activity or on resting. Angina is caused by narrowing of the coronary artery. The narrowed coronary artery compromises the blood flow resulting in inadequate blood flow to meet the demand made by the heart muscles, causing angina. On resting, the demand decreases and the blood flow in the coronary arteries become sufficient and the angina disappears.
2) Heart attack is caused by sudden blockage of the coronary artery often caused by rupture of a cholesterol plaque in the artery. This results in deprivation of the blood flow to the area of heart muscle supplied by that artery, resulting in damage to the heart muscles. Immediate treatment of a heart attack is essential to save the heart muscles. If the blood flow is not restored within about six hours after a heart attack, the damage to the heart muscles became permanent resulting in diminution in the effective strength of the heart.
3) Silent Heart Disease: A patient does not always suffer from typical chest tightness when he sustains coronary heart disease. Patients, with diabetes often suffer from silent heart disease when they also have coronary heart disease. The disease may manifests as progressive tiredness, or breathlessness or even indigestion.
Treatment of coronary heart disease:
The management of avoidable causes and healthy lifestyle changes play an important role in the treatment. The specialist would determine the appropriate investigations to determine the cause and extent of the disease, to stratify the management plan. The investigations would include blood tests, ECG, Treadmill Stress Test, and Echocardiogram. Based on these results further tests may be required such as nuclear perfusion scan and coronary angiogram. Coronary angiogram is the ultimate gold standard which would reveal the exact road map of the coronary arteries, the distribution of cholesterol plaques and narrowing in the coronary arteries which would ultimately determine the necessity of invasive treatment. About a third of patients can be managed by medical treatment requiring a combination of medicines. In others, coronary angiogram will be required. Depending on the site, extent and number of blocks assessed in the coronary angiogram, your Cardiologist would determine the treatment plan. If the lesions are suitable for balloon dilation and deployment of stents, such treatment will be advised.
In more extensive situations, coronary bypass surgery would be required. During bypass surgery, bridges to bypass the block on the affected coronary arteries are constructed. Usually 3-4 bypasses are required. The heart surgeon would assess you and decide on the type of conduit required to carry out the bypass. Often the mammary artery which runs underneath the breastbone is used. Other bypass conduits may be taken from the forearm and legs. Removal of these arteries and veins do not cause any permanent harm.
The surgery can be carried out with or without using a heart lung machine. Both methods have their own indications and advantages. Your surgeon will be able to discuss the issue with you.