Left coronary angiogram in RAO caudal view, showing lesion in left anterior descending coronary artery (1) and left circumflex coronary artery (2). Lesion in the left circumflex coronary artery (LCX) is at the bifurcation point at which the major obtuse marginal artery takes off. The lesion involves the ostium of the obtuse marginal artery which is very tight. There is mild plaquing of the LCX proximal to the lesion as well. Dye reflux from left main coronary artery (LMCA) into the aorta is also seen. If dye reflux is not seen, it could be due to ostial lesion of the LMCA causing a wedging of the catheter. In this situation, damping of the catheter tip pressure will be noticed on the hemodynamic monitor.