Types of angina

Stable Angina. Stable angina can be extremely painful, but its occurrence is predictable; it is usually triggered by exertion or stress and relieved by rest. Stable angina responds well to medical treatment. Any event that increases oxygen demand can cause angina, including exercise, cold weather, emotional tension, and even large meals. Angina attacks can occur at any time during the day, but a high proportion seems to take place between the hours of 6:00 AM and noon.

Unstable Angina. Unstable angina is a much more serious situation and is often an intermediate stage between stable angina and a heart attack. A patient is usually diagnosed with unstable angina under the following conditions: pain awakens a patient or occurs during rest, a patient who has never experienced angina has severe or moderate pain during mild exertion (walking two level blocks or climbing one flight of stairs), or stable angina has progressed in severity and frequency within a two-month period. Medications are less effective in relieving pain of unstable angina.

Prinzmetal's Angina. A third type of angina, called variant or Prinzmetal's angina, is caused by a spasm of a coronary artery. It almost always occurs when the patient is at rest. Irregular heartbeats are common, but the pain is generally relieved immediately with treatment.

Silent Ischemia. Some people with severe coronary artery disease do not experience angina pain, a condition known as silent ischemia, which some experts attribute to abnormal processing of heart pain by the brain.