Hemopump ventricular support for patients undergoing high risk coronary angioplasty. Prophylactic implantation of a Hemopump (Johnson and Johnson, Skillman, NJ) has been evaluated in nine patients selected for high risk coronary angioplasty. They were unstable patients, refractory to maximal pharmacology, with indications for revascularization, but contraindications for surgery such as low ejection fraction and lack of material for bypass. In all, the target lesion was located on the last patent vessel. The pump was inserted under local anesthesia, without any graft. A specially designed occluder permitted avoidance of retrograde bleeding during implantation. The bypass flow ranged from 2.5 to 3.2 L/min, and permitted a rise in cardiac index from 2.05 to 2.55 L/min/m2, with a drop in capillary wedge pressure from 13 (7-18) to 10 (7-13) mmHg. During balloon inflation, no electrocardiographic changes were observed, because only minor ventricular arrhythmias occurred. No significant hemolysis was seen (plasma free hemoglobin less than 10 mg/dl in all) after 2 hr of pumping. The only limitation of the technique appears to be difficulty at the time of implantation from narrow, stenosed, or tortuous iliofemoral arteries (3 patients). This experience strongly supports the benefit of temporary left ventricular Hemopump support in high-risk situations and clearly shows the need for a smaller pump. 