The Angina Manual

Angina normally seems like a pressing or squeezing pain, felt in the chest under the breast bone, but in some cases stretching up to the shoulders, arms, neck, jaws, or back. 
Angina is typically brought on by exertion. It takes place when the heart's need for oxygen rises beyond the oxygen offered from the blood nourishing the heart. Physical exertion is the most typical cause for angina. Other triggers can be psychological fatigue, extreme cold or heat, heavy meals, alcohol, and cigarette smoking.
But bear in mind, angina is different from a heart attack. Angina pain means that some of the heart muscle in not getting sufficient blood for the short term, such as during exercise, when the heart has to work harder. The pain does NOT mean that the heart muscle is struggling with irreparable, permanent injuries. Periods of angina rarely lead to long-lasting damage to heart muscle. It is typically relieved within a few minutes by resting or by taking prescribed angina medicine.
On the flip side, a heart attack happens when the blood flow to a part of the heart is suddenly and entirely cut off. This creates permanent damage to the heart muscle. Typically, the chest pain is more severe, lasts longer, and does not go away with rest or with medicine that was earlier successful. It may be complemented by indigestion, nausea, weakness, and sweating. Having said that, the indicators of a heart attack are wide-ranging and may be considerably less severe.
When a person has a repeating but consistent pattern of angina, it does not mean that a heart attack is about to occur. Angina means that that there is underpinning coronary heart disease. Patients with angina are at an expanded risk of heart attack in comparison with those who have no symptoms of cardiovascular disease, but the episode of angina is not a signal that a heart attack is about to occur. On the flip side, when the pattern of angina changes--if episodes become more common, last for a longer time, or take place without exercise--the threat of heart attack in up coming days or weeks is much greater.
A person who has angina needs to know the pattern of his or her angina--what causes an angina attack, what it feels like, how long episodes usually last, and whether medication relieves the attack. If the pattern changes greatly or if the symptoms are those of a heart attack, one should get medical help straightaway, perhaps best done by looking for an evaluation at a nearby hospital emergency room.
Take note, however, that not all chest pain is angina, or associated to the heart. If the pain lasts fewer that 30 seconds or if it goes away during a deep breath, after drinking a glass of water, or by just changing position, it almost definitely is NOT angina and should not cause headache. But extended pain, unrelieved by rest and accompanied by other discomforts may signal a heart attack.
Generally the doctor can establish angina by noting the indicators and how they surface. Nonetheless one or more diagnostic tests may be needed to exclude angina or to determine the seriousness 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 monitors electrical impulses of the heart. These may indicate that the heart muscle is not getting as much oxygen as it really needs ("ischemia"); they may also show problems in heart rhythm or some of the other probable defective 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 happen during pressure. Therefore, the functioning of the heart may be tested under stress, typically exercise. In the most basic 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 calls for picturing the blood flow pattern in the heart muscle in the course of peak exercise and after rest. A tiny amount of a radioisotope, usually thallium, is shot into a vein at peak exercise and is used up by normal heart muscle. A radioactivity detector and computer record the pattern of radioactivity distribution to various parts of the heart muscle. Local variances in radioisotope concentration and in the rates at which the radioisotopes disappear are measures of imbalanced blood flow due to coronary artery narrowing, or due to malfunction of uptake in scarred heart muscle.
The most complete way to assess the presence and severeness of coronary disease is a coronary angiogram, an x-ray of the coronary artery. A long slim 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.