Fig. 1

Normal coronary anatomy. A Schematic for normal coronary artery origin and course off the aorta in relation to the pulmonary artery; B–D represent short axis views of the aortic valve; B normal origin of the right coronary artery (RCA); C normal origin of the left main stem (LMS); D normal bifurcation of the LMS, into the left anterior descending (LAD) and circumflex (LCx) arteries