Coronary angiography is used to image the arteries that supply the heart muscle with blood. Angiography can image narrowed or blocked coronary arteries, which are not visible on a normal X-ray. A local anaesthetic is injected, and a fine, flexible catheter is passed into the femoral artery, through the aorta, and into a coronary artery. Contrast dye is injected through the catheter, and a series of X-rays is taken. The procedure is painless, but you may feel a flushing sensation as the dye is injected.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.