A system and method for perfusing a liquid medicament into tissue of a patient requires a catheter having a distal barrier and a proximal barrier mounted on the catheter. A perfusion section is formed into the catheter between these barriers. By way of example of a typical operation, the catheter is advanced through the vasculature of a patient and into the coronary sinus. Advancement continues until the barriers of the catheter are positioned to straddle the ostium of the left atrial vein. As so positioned, a perfusion chamber is established in the coronary sinus between the barriers. Also, the perfusion chamber is positioned for fluid communication with the left atrial vein. Liquid medicament can then be transferred from a source into the perfusion chamber for perfusion of the medicament into tissue of the atrial vein.
