Unstable angina happens when blood flow to the heart is suddenly slowed by narrowed coronary arteries. Or small blood clots form in the coronary arteries and slow blood flow. Typically, there is no damage to the heart muscle. It often happens when you are at rest. You may have had stable angina before. You knew when to expect your symptoms, such as when you exercised. Stable angina usually goes away when you rest or take your angina medicine. But the symptoms of unstable angina may not go away with rest or medicine. It may get worse or happen at times that it didn't before. Unstable angina is not a heart attack. But it is a warning that a heart attack could happen soon, so it needs to be treated right away.
A heart attack means a coronary artery has been blocked and the heart has been damaged. Without blood flow and oxygen, part of the heart starts to die.
Any type of acute coronary syndrome is very serious and needs to be treated right away.
Atherosclerosis causes a substance called plaque to build up in the coronary arteries. Plaque causes angina by narrowing the arteries. The narrowing limits blood flow to the heart muscle. A heart attack happens when blood flow is completely blocked.
What are the symptoms?
Call 911 or other emergency services immediately if you have symptoms of acute coronary syndrome. These may include:
Chest pain or pressure, or a strange feeling in the chest.