Ischemic heart disease refers to damage to the heart caused by a lack of oxygen supply. Since oxygen is delivered by the red blood cells that course through the arteries in the body, damage to the arteries results in reduced blood flow, and subsequently a reduction in oxygen delivery. This process can occur anywhere in the body; when the topic of discussion is the heart, the coronary arteries (the arteries that deliver blood to different areas of the heart) are the major point of focus.
Coronary artery disease is the number one cause of mortality in most developed countries. These arteries can become damaged over time, such as from the buildup of cholesterol plaques known as atherosclerosis. As the blood vessels become damaged, the risk of ischemic heart disease increases. This process may lead to symptoms of pain with exertion (called angina), silent ischemic episodes, or the classic full-blown heart attack (when a coronary artery becomes totally occluded).
Your father was told that he has ischemic heart disease, meaning that there is some evidence (either on his EKG
or other imaging of the heart) that his heart has been damaged in the past, most likely as a result of coronary artery disease leading to a lack of the required amount of oxygen demanded by the heart muscle. You and your father should have a discussion with his doctor
about the degree of his heart disease and what measures can be taken to help improve his cardiovascular health.