What commonly causes myocardial ischemia as indicated by EKG changes?

Myocardial ischemia occurs when there is an insufficient supply of oxygen to the heart muscle, often due to an obstruction in the blood flow. This reduced blood flow can lead to detectable changes on an electrocardiogram (EKG). The most common cause of these changes is coronary artery blockages, which typically occur due to the buildup of plaque within the coronary arteries. This plaque can narrow the arteries, restricting blood flow, and as a result, the heart muscle may not receive the necessary oxygen it needs, leading to ischemia.

On an EKG, myocardial ischemia can manifest as changes such as ST-segment depression or T-wave inversion, which are indicators that the heart is not being adequately perfused. Recognizing these alterations is critical as they can help in diagnosing conditions like angina or myocardial infarction.

While high cholesterol levels, low calcium levels, and rapid heart rates can be related to various cardiovascular conditions, they do not directly cause the EKG changes associated with myocardial ischemia in the same way that coronary artery blockages do. Thus, understanding the direct relationship between coronary artery obstructions and myocardial ischemia, as reflected on an EKG, is essential for anyone studying to become a Certified EKG Technician.