How is coronary heart disease diagnosed?
Coronary heart disease (coronary artery disease, coronary artery heart disease, ischemic heart disease) is usually suspected by the symptoms. Typically it is a central chest pain or discomfort induced by exercise and relieved by rest. But this need not be the case always. Pain of heart attack may appear all of a sudden and does not get relieved by rest. Still it is an important manifestation of coronary heart disease. Other symptoms associated with chest pain could be pain in the jaw or arms, excessive sweating along with pain or sometimes breathlessness or dizziness. First investigation to be done is usually an ECG (electrocardiogram). When a heart attack is suspected, other investigations done in the emergency department are a bedside echocardiogram and a blood test for Troponin, which is released into the blood when heart muscle is damaged. Finally an emergency coronary angiogram may be done if there is evidence of a heart attack. In the outpatient setting, a treadmill exercise ECG (treadmill test) can be done in stable patients resting ECG does not give a diagnosis. Other advanced tests are coronary CT angiogram and nuclear scan of the heart.
LMCA: Left main coronary artery; LAD: Left anterior descending coronary artery (blood vessels supplying oxygenated blood to the the heart muscle) – as seen on coronary angiogram (X-ray imaging after injecting iodinated contrast into the vessel)
What is ischemic heart disease?
Ischemia means a decrease in the blood supply. Hence ischemic heart disease means blood flow to the heart muscle is reduced. Ischemic heart disease is also known as coronary artery disease. Usually this occurs due to partial or complete blocks in the coronary arteries which supply oxygenated blood to the heart muscle. It could also occur due to transient contraction of the muscle of the blood vessel, known as ‘coronary vasospasm’. Ischemic heart disease due to partial blockage of the blood vessels usually manifest as chest pain on exertion (effort angina). When the block is near total or total there could be chest pain at rest as well. Then it is called unstable angina or sometimes when there is damage to the heart muscle it results in heart attack (technical term: myocardial infarction).
Does ischemic heart disease always manifest with chest pain?
Ischemic heart disease can have other manifestations like breathlessness on exertion, dizziness, undue sweating on exertion, or pain in the jaw, wrist, neck or back. These are known as anginal equivalents, meaning symptoms of ischemic heart disease other than chest pain. Occasionally there is no symptom at all and it is detected on routine medical evaluation for some other reason. Then it is called silent ischemia or even silent heart attack.
Is there any difference in the significance between silent and manifest ischemic heart disease?
Significance is the same for silent and manifest ischemic heart disease. But the risk is probably more for the silent one because there is no warning symptoms and the individual would not take care and exert beyond what his medical condition permits and may end up with more severe problems.