Last week we discussed the warning signs of heart disease, and the various types of heart disease. When one suspects a cardiac problem, there are a large number of tests which can be done to diagnose the condition. These tests are usually done in a sequential manner, starting with the most basic test, the ECG. Some of the commonly done cardiac tests are described below.
This is usually the first cardiac test recommended when one is suspecting a heart problem. Electrodes (they look like small stickers with a metal tip) are applied to various points on the upper body, and on your ankles. An ECG measures the electrical activity of the heart. A change in the ECG pattern can be indicative of the presence of heart disease. The doctor usually looks for two types of changes –
- changes which indicate a block in the coronary arteries
- changes which indicate a problem with the rhythm of the heart beats, such as palpitations.
Stress test / stress ECG:
During a stress test you are made to walk on a treadmill while your ECG and blood pressure is measured. The speed of the treadmill is gradually increased and the goal is to keep walking till you are exhausted and cannot walk any farther. The stress ECG provides more information than a rest ECG since the oxygen demand on your heart is greater while exercising. A positive stress test indicates that there are changes on your ECG which are suggestive of a block in your heart (coronary) arteries. A stress test also gives you information on your cardiovascular fitness.
This tests the pumping function of the heart. It also helps to study the motion of the heart valves which control the flow of blood in and out of the heart. During the test, sound waves are bounced off the surface of the heart to produce a picture on the screen.
Thallium stress test / nuclear medicine stress test:
This stress test is like a regular stress test, but a dye is injected into the heart and pictures are taken of the heart, before and after the stress test. This test can detect areas of the heart muscle that have been damaged by a heart attack and areas that are not getting enough oxygen due to partial blockages of the coronary arteries. Nuclear medicine tests can also provide information on the functioning of the left ventricle. These tests are more accurate than standard exercise tests and are often performed when stress test results are inconclusive.
Coronary angiogram or angiography:
This is the ‘gold standard’ of all tests to detect heart disease. This test identifies the specific locations of blockages or narrowings in the coronary arteries. It also determines the severity of any blockages present and evaluates the functioning of the left ventricle (the largest chamber in the heart). This information is essential to determine if heart surgery is needed.
To perform the test a thin plastic tube (catheter) is inserted into an artery in the leg and is threaded upto the coronary arteries. Dye is injected into the coronary arteries while an x-ray machine shoots numerous pictures from various angles. You are fully conscious during the test which does not take more than half an hour.
Treatment for Heart Problems:
Your cardiologist will use the results of your diagnostic tests, along with your personal history, to outline options for treating your problems. Often medication, along with changes in lifestyle, is all that is needed.
If you have coronary heart disease, you may need an intervention such as an angioplasty, or coronary bypass surgery. The goal of an angioplasty, or bypass surgery is the same – to improve the blood supply to the heart muscle.
Angioplasty and stent placement:
In an angioplasty a catheter is inserted into an artery in the leg and is threaded upto the coronary arteries. A balloon is passed through the catheter and is inflated to widen the coronary artery at the site where it has become narrowed by plaque. Often a thin cylinder of wire mesh, called a stent is placed at the site of the blockage after it has been dilated. However, even after an angioplasty one needs to be careful and lead a heart-healthy life, or there is a high chance of the blockage forming again. In about 15-20% of cases, the arteries again close due to process called restenosis. If this has to occur, it usually takes place within the first six months. In the last six months, drug coated stents have been introduced, which greatly lower the chances of restenosis.
Coronary artery bypass graft surgery:
As the name suggests, in this surgery an artery is taken from a part of the body and is used to detour the block. The most common sites from where an artery is removed is from the chest, known as the internal mammary artery or from the arm, known as the radial artery. A bypass surgery is much more invasive than an angioplasty, and involves cutting of the breast-bone, and the recovery process takes about six weeks.
Thanks & Regards,
Dr. Aashish Contractor
Head of Dept: Preventive Cardiology andRehabilitation
Asian Heart , MMRDA ,Bandra East, Mumbai