Coronary arteries are vessels that provide oxygen-rich blood and other nutrients to the heart muscle. The two main coronary blood vessels, which branch from the body's main artery (aorta), are the right coronary artery (RCA) and the left coronary artery (LCA).

The coronary arteries attach to and wrap around the heart's surface. The left side of the heart is larger and more muscular because it pumps blood to the rest of the body. The left coronary artery branches off into smaller arteries, the most prominent of which are the:

• Left anterior descending artery, which supplies blood to the front of the heart.
• Left circumflex artery, which encircles the heart muscle, supplying blood to the back of the heart.

The right side of the heart pumps blood to the lungs and related structures. The right marginal branch usually extends from the right coronary artery and supplies blood to the lower right side of the heart.