A heart attack occurs when this same process lasts long enough to cause permanent damage to the heart muscle. This is similar to the difference between a TIA (transient ischemic attack), where the blood supply to the brain is compromised and there is transient neurologic dysfunction, as compared to a stroke, where part of the brain is irreversibly damaged.
The most common cause of angina and a heart attack is from cholesterol build up (plaques) leading to narrowing of the blood vessels that bring blood to the heart muscle. Sometimes these plaques grow slowly, and sometimes the plaque tears or ruptures, and a blood clot forms, acutely narrowing the artery partially (angina) or completely (heart attack or myocardial infarction).
There are rare instances where the cause of angina or a heart attack is not from cholesterol build-up but from spasm of the artery, or an embolus to the coronary artery, or a heart valve problem, or a failure of the microvasculature to dilate appropriately when the heart muscle is working hard and needs more oxygen.
The important thing is to recognize the symptoms of angina or a heart attack and get the proper treatment. The classic symptom is a central chest pressure that may radiate to the neck or left arm, and is associated with shortness of breath. However, symptoms are quite variable between people and may present as stomach discomfort, jaw pain, left or right shoulder pain, or just shortness of breath and a vague uncomfortable feeling.
Any similar symptom that is predictably brought on by exertion, and resolves with rest, is worrisome for angina. Any similar symptom that continues for more that 10-15 minutes unabated is worrisome for a heart attack in progress and you should call 911 and get to the nearest hospital.
It is important to have your angina thoroughly evaluated. There are several reasons for this. We have to determine if there is a dangerous problem that should be fixed BEFORE a heart attack occurs. If it is not a dangerous problem, we need to get you on the right medicines and lifestyle changes to mitigate your symptoms and prevent progression of the plaques that you do have. With the doctor and the patient both working together, we can even get the plaques to regress, or get smaller over time.