thus the area blocked by the aortic catheter in boyd et al will necessarily decrease the flow rate of oxygenated blood to the head and upper body any attempt to increase the flow rate by increasing the velocity of the fluid exiting the catheter may actually dislodge and direct plaques and other debris into the head and neck realizing that there is a constant tension between providing a catheter small enough to offer ease of insertion into and removal from a vessel but also large enough to provide appropriate perfusion levels at acceptable velocities the present invention departs from the conventional minimally invasive catheter systems the terms proximal and distal are utilized herein to facilitate the description of the elements of the present invention proximal as utilized herein refers to a direction or location which is closer to the heart than another element while distal refers to a direction or location which is further from the heart than another element one preferred system in accordance with the present invention comprises three specialized catheters as illustrated in fig1 this three catheter system includes an aortic occlusion catheter 20 a femoral access venous return catheter 60 and a femoral access arterial return catheter 80 for a system providing aortic occlusion extracorporeal circulation cardiac arrest and cardiac venting the aortic occlusion catheter 20 of the present invention is specifically designed for insertion into a peripheral vessel the aortic occlusion catheter 20 terminates in a soft flexible tip 26 which facilitates the smooth insertion and positioning of the catheter through a peripheral vessel such as the left subclavian artery 22 the left subclavian artery 22 provides a smooth path for insertion and virtually directs the catheter into place in the ascending aorta 24 however the aortic occlusion catheter is.