The coronary arteries supply blood to the heart muscle. The right coronary artery supplies both the left and the right heart; the left coronary artery supplies the left heart. Update Date: 07/15/2008Alan Berger, MD, Assistant Professor, Divisions of Cardiology and Epidemiology, University of Minnesota, Minneapolis, MN. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.