Coronary arteries are blood vessels that provide oxygen-rich blood and other nutrients to the heart muscle. The coronary arteries attach to and wrap around the heart's surface.

The left coronary artery branches off into smaller arteries. The most prominent ones 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 coronary artery supplies the back of the heart. The right marginal branch usually extends from the right coronary artery and supplies blood to the lower right side of the heart.