Lyme disease is a multisystem illness that may affect the heart. Borrelia burgdorferi infection should be suspected in all patients with unexplained cardiac symptoms who are or who have been exposed to endemic areas. Prompt diagnosis and treatment are needed to avoid potentially life-threatening complications, as well as the inappropriate insertion of a permanent pacemaker. The author reviews the cardiac complications associated with Lyme disease, and provides diagnostic and therapeutic approaches for effective patient care.