In a patient_forum of coronary artery disease, we must always remember that medicine is not a precise science. Medical practitioners learn by observing carefully, comparing promising new treatments with accepted treatments, and studying diseases in the laboratory. But, the situation in a particular patient (you or one of your loved ones) is always unique and the lessons that apply to most patients may not apply to that patient. This is the reason we use "fuzzy" words such as "usually," "almost never," and so forth, and that we mention other disease that can cause the same or similar symptoms. It is also the reason that the patient must always be under the care of a qualified physician who works in an environment that allows her or him to take excellent care of patients.

Stenoses in the coronary arteries can cause several different disorders that are discussed below. I summarize them here so you can decide what to read next. Please remember that each of these disorders can be caused by other factors: not everyone with these symptoms has the disorder, not everyone with the disorder has these symptoms, and not everyone with the disorder has it because of coronary stenoses. Humankind didn't make diseases; we just do our best in dealing with it!

• If they grow slowly, coronary stenoses reduce the blood supply to part of the heart muscle (the "myocardium"). This can cause discomfort, or "angina pectoris," that usually begins with exercise or emotional stress, and goes away with rest.

• If a stenosis becomes very severe or turns into complete closure ("occlusion") of an artery, the heart muscle it ordinarily supplies can die, or "infarct". This is what is commonly referred to as a "heart attack" or "myocardial infarction."

• The in-between state is called "unstable angina" and is usually characterized by the discomfort of angina pectoris that occurs at rest, with less exertion than usual, with different pain than usual, or with less relief from nitroglycerin than usual. People with unstable angina are much more likely to have a myocardial infarction for about two weeks after symptoms begin, and therefore should be in a hospital as soon as the symptoms begin.

• Finally, about 1 out of every 4 people who have heart attacks do not realize they are having them. They may think they have indigestion, a muscle strain in the chest, or just shortness of breath. These people can accumulate significant damage to the heart muscle before they realize they have a heart problem. When the heart muscle is damaged, the patient can develop "congestive heart failure". Don't be frightened by this term. When the heart muscle is really failing, a different term is used (cardiogenic shock). Congestive heart failure comes in various sizes and flavors ranging from ankle swelling to shortness of breath to feeling tired all the time.

Again, please remember that each of these disorders can be caused by other factors: not everyone with these symptoms has the disorder, not everyone with the disorder has these symptoms, and not everyone with the disorder has it because of coronary stenoses.