What is ischemia?
Ischemia is the medical term for what happens when your heart muscle doesn't get enough oxygen. Ischemia usually happens because of a shortage of blood and oxygen to the heart muscle. It is usually caused by a narrowing or blockage of one or more of the coronary arteries (which supply blood to the heart muscle). In many cases ischemia is a temporary problem. Your heart may be able to get enough blood through your diseased coronary arteries while you are resting but may suffer from ischemia during exertion or stress.
What is chronic ischemia?
Your coronary arteries may become so narrowed that they limit the flow of blood to your heart all the time, even when you are at rest. If this happens, ischemia can become an ongoing (chronic) condition that can progressively weaken your heart.
What is angina?
When your heart suffers from ischemia, you will typically experience pain or discomfort in your chest. Angina is the medical term for this chest sensation, which is the most common symptom of coronary artery disease (CAD).
It's important to know that people with CAD who experience angina often describe the sensation as "tightness," "discomfort," "squeezing," and "heaviness." The pain or discomfort of angina tends to start under your breastbone but may also travel, often to your shoulder, arm, neck, or jaw. Often people also have shortness of breath, sweating, and a feeling of nausea along with the anginal chest pain or discomfort. Sometimes ischemia causes these other symptoms without causing chest pain or discomfort.
What is silent ischemia?
For reasons that doctors don't fully understand, some people have ischemia but do not feel chest pain or discomfort or any other symptoms. This condition is called silent ischemia. Silent ischemia occurs most often in women, older people, and people who have diabetes.
People with silent ischemia typically find out that they have it when their doctor notices that their routine electrocardiogram (EKG), ambulatory EKG, or stress test results indicate that their hearts aren't getting enough blood. Silent ischemia is a particular concern after a heart attack, because it increases the chance of another heart attack.