Figure 1: Catheterization of the coronary sinus. In anesthetized pigs, two catheters were introduced through the jugular vein into the coronary sinus. One of them, the Swan-Ganz (SG) catheter equipped with a balloon, was placed in a proximal position. The multi-purpose (MP) catheter, placed in a more distal position, was used to retrogradely inject contrast solution immediately after the balloon (black arrow) of the former catheter was inflated. Upper left: fluoroscopic view of MP catheter placement in the coronary sinus; Lower left: fluoroscopic view of MP and SG catheter placement in the coronary sinus with inflated balloon (black arrow); Upper right: fluoroscopic view after balloon inflation (black arrow) and injection of contrast solution into the coronary sinus and azygos vein (AzV); Lower right: contrast solution disappearance after balloon deflation.