ABSTRACTCatheter balloon inflation performed during percutaneous transluminal coronary angioplasty (PTCA) results in temporary interruption of coronary blood flow and subsequent myocardial ischemia. This produces transient but profound regional left ventricular dysfunction. In an effort to mitigate this inflation-related dysfunction, oxygenated Fluosol DA 20%, a perfluorochemical oxygen transport fluid, was infused distal to the balloon through the central lumen of the dilating catheter during balloon inflation. Regional wall motion during PTCA was assessed by simultaneous continuous two-dimensional echocardiography and was quantified by computer analysis. During control inflations accompanied by no intracoronary infusion or by transcatheter infusion of Ringer's lactate solution or nonoxygenated Fluosol DA 20%, there was profound regional left ventricular dysfunction with a greater than 90% decrease in regional contraction. In contrast, regional contraction during transcatheter infusion of oxygenated Fluosol DA 20% remained at normal levels throughout balloon inflation. Distal infusion of Fluosol DA 20% during balloon inflation is a useful adjunct to PTCA, allowing longer inflation times and perhaps permitting PTCA to be performed safely in patients with significant myocardium at ischemic risk or with limited left ventricular reserve for whom the procedure is currently believed to be too hazardous.