ECG, or electrocardiogram, is the process of recording and analyzing electrical activity produced by heart cells that enables the heart to function.
Atherosclerosis is a disease caused by narrowing and hardening of the blood vessels due to the accumulation of plaques in the artery.
Angiography is an examination of blood vessels under X-rays using a kind of medical dye. It is performed by physicians in the angio laboratories.
Ischemia is a serious condition in which blood flow to any organ in the body is stopped. During ischemia, blood vessels providing oxygen to brain, is blocked.