What Tests and Procedures Diagnose Heart Disease?
Your first symptom of coronary heart disease may be a heart attack or sudden cardiac arrest. Medical professionals use screening tests to detect the presence and severity of coronary disease before it causes problems or sends you to an emergency department with severe symptoms.
The symptoms of coronary heart disease are what medical professionals call nonspecific. This means the symptoms could be caused by many different conditions, and some not related to the heart. The doctor will gather information from you so that he or she can rule out conditions and pinpoint the correct diagnosis. These include asking questions about your symptoms, medical and surgical history, general health and specific medical problems, and the medications you take, phyical exam an electrocardiogram (ECG), and possibly lab tests and imaging tests such as X-ray or CT scan.
The doctor will be to rule out a heart attack or other life-threatening condition. The usual tests include blood tests, ECG, and, possibly, chest X-ray. Blood tests might check your blood cells, the chemical makeup of your blood, and enzymes leaking out of damaged heart muscle, that suggest that you are having a heart attack. Other tests might be ordered depending on the circumstances.
ECG is a painless test that measures the electrical activity of the heart. It can reveal several different heart problems, including ischemia, heart attacks, rhythm disorders, long-standing strain on the heart from high blood pressure, and certain valve problems. It gives clues as to the underlying cause of cardiac symptoms. The test takes just a few minutes. You lie on a table with electrodes fastened to the skin of your chest, arms, and legs, and a chest X-ray. A chest X-ray can show abnormalities in the size or shape of the heart and can show whether any fluid is building up in the lungs.
An ECG involves measuring ECG tracings before, during, and after stressing the heart by exercise. You will walk on a treadmill while connected to an ECG machine. This test is 60-70% accurate in showing blockages in blood flow in 1 or more of the 3 coronary arteries. Sometimes its readings may be falsely abnormal for people taking certain medications or who have certain medical problems not directly related to coronary heart disease.
Treadmill exercise stress test.
If other tests suggest blockage of the coronary arteries, you may undergo a nuclear (radionuclide) stress test. During this test, after a tiny dose of a radioactive tracer is injected into a vein, a special camera can identify the quantity of blood flow that reaches different parts of the heart muscle. The substance most often used is sestamibi, so this is often called a sestamibi (MIBI) stress test. You will have 2 tests, one with stress, or exercise (on a treadmill), and the other at rest. If you cannot exercise, you will be given a drug to temporarily stress your heart. The drugs used for this are adenosine (Adenocard), dipyridamole (Persantine), or dobutamine (Dobutrex). This test is expensive, but it is noninvasive, and its accuracy is quite good.
Stress nuclear imaging using single photon emission computed tomography (SPECT) Results of a nuclear stress test from a person with angina. A significant defect in the amount of blood pumped during stress appears to a major blockage (stenosis) in the right coronary artery.