2 Heart Disease



Diagnosing Angina

Usually the doctor can diagnose angina by noting the symptoms and how they arise. However one or more diagnostic tests may be needed to exclude angina or to establish the severity of the underlying coronary disease. These include the electrocardiogram (ECG) at rest, the stress test, and x- rays of the coronary arteries (coronary "arteriogram" or "angiogram").

The ECG records electrical impulses of the heart. These may indicate that the heart muscle is not getting as much oxygen as it needs; they may also indicate abnormalities in heart rhythm or some of the other possible abnormal features of the heart. To record the ECG, a technician positions a number of small contacts on the patient's arms, legs, and across the chest to connect them to an ECG machine.

For many patients with angina, the ECG at rest is normal. This is not surprising because the symptoms of angina occur during stress. Therefore, the functioning of the heart may be tested under stress, typically exercise. In the simplest stress test, the ECG is taken before, during, and after exercise to look for stress related abnormalities. Blood pressure is also measured during the stress test and symptoms are noted.

A more complex stress test involves picturing the blood flow pattern in the heart muscle during peak exercise and after rest. A tiny amount of a radioisotope, usually thallium, is injected into a vein at peak exercise and is taken up by normal heart muscle. A radioactivity detector and computer record the pattern of radioactivity distribution to various parts of the heart muscle. Regional differences in radioisotope concentration and in the rates at which the radioisotopes disappear are measures of unequal blood flow due to coronary artery narrowing, or due to failure of uptake in scarred heart muscle.

The most accurate way to assess the presence and severity of coronary disease is a coronary angiogram, an x-ray of the coronary artery. A long thin flexible tube (a "catheter") is threaded into an artery in the groin or forearm and advanced through the arterial system into one of the two major coronary arteries. A fluid that blocks x-rays (a "contrast medium" or "dye") is injected. X-rays of its distribution show the coronary arteries and their narrowing.


What is Angina?  *   Types of AnginaTesting for Angina  * Treatment for Angina 



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