Unstable Myocardial Ischemia
Unstable myocardial ischemia is a dangerous condition that requires emergency treatment. It is a sign that a heart attack could occur soon. Unlike stable myocardial ischemia, it does not follow a pattern. It can occur without physical exertion and is not relieved by rest or medicine.
Variant Myocardial Ischemia
Variant myocardial ischemia is rare; it usually occurs at rest. The pain associated with this can be severe, and usually occurs between midnight and early morning. This pain can usually be relieved by medicine.
As mentioned, myocardial ischemia is caused by a temporary lack of oxygen-rich blood to the heart muscle. This decrease in blood flow can happen for a number of reasons and will vary based on the type. In most cases, the cause of myocardial ischemia is coronary artery disease (CAD), or what most people refer to as just heart disease. Sometimes, other types of heart disease (such as aortic stenosis) or uncontrolled high blood pressure (hypertension) can cause it.