What is ischemia? if the heart receives its own blood supply during diastole when would ischemia most likely become a problem?

It is believed by most doctors that if a stress test is abnormal, then the patient has obstructive coronary artery disease of sufficient degree to interfere with flow of blood to the heart muscle. When this happens, the heart muscle is said to be ischemic. Ischemia does not occur at normal heart rates in most patients because at rest, with a normal heart rate, the heart muscle's need for blood is comparatively small, and the amount of obstruction of the coronary arteries is not great enough to reduce the flow of blood to the heart muscle. During stress, however, when the heart rate speeds up, and the heart has to work harder, the heart muscle requires a great deal of extra blood to generate the energy needed to perform the extra work. Now, the obstruction to the coronary arteries may be great enough, to prevent the blood flow from increasing, and the heart muscle will become ischemic.

Ischemia is a medical term that refers to restriction in the blood supply to the tissues. In this condition, the heart muscles do not get adequate amount of oxygen. Here shortage of both blood and oxygen occurs in the heart muscles.

If the heart receives its own blood supply during diastole but spends less time in the diastolic stage increases the problem of ischemia. If the amount of blood decreases in the diastole or not properly filled with blood, diastole dysfunction occurs.