inferior vena cava A major vein that carries deoxygenated blood from the lower part of the body (abdomen and legs) back to the heart.
intermittent claudication Exercise-induced, sporadic pain in the muscles of a limb, resulting from reduced blood flow.
invasive techniques Medical procedures that involve a surgical incision, needle puncture, or passage of a tube (catheter) into an artery.
ischemia A deficiency in oxygen in parts of the body because of an obstructed blood vessel. For example, ischemic heart disease is the result of narrowing of the coronary arteries that supply blood to the heart muscle.