The system for removing blood containing contrast dye includes an inner catheter having a fixed proximal end and a distal free end, and an outer catheter coaxially disposed around a portion of the inner catheter, defining an inner lumen and an annular outer lumen. The fixed end of the inner catheter is coincident with the proximal end of the outer catheter, and the distal end of the inner catheter extends outward from the outer catheter. A valve manifold provides a single operator control over the operation of the catheters and balloon in order to drain the dye from the coronary sinus system.