HEMODYNAMIC PROFILES DURING CONCURRENT INTRAAORTIC BALLOON PUMPING AND VENOARTERIAL BYPASS - A CANINE STUDY COMPARING SUBCLAVIAN AND FEMORAL-ARTERY PERFUSION SITES

Concomitant use of venoarterial bypass (VAB) with centrifugal pump and intraaortic balloon pumping (IABP) is a common technique for cardiopu lmonary resuscitation. This experimental study examines whether corona ry perfusion and hemodynamics are affected by the site of the blood su pply, comparing the subclavian artery and the femoral artery. VAB and IABP were performed in 11 mongrel dogs with cardiopulmonary failure in duced by acute myocardial infarction and hypoventilation. Aortic root pressure (AP), left atrial pressure, central venous pressure and coron ary sinus blood flow (CSF) were measured, and blood gas analysis was p erformed. Subclavian artery perfusion (SAP) and femoral artery perfusi on (FAP) were compared at bypass ratios of 25, 50, 75, 85, 100%. At by pass ratios of 75% and 85% the mean systolic AP was higher with SAP th an with FAP. The mean diastolic AP was higher with SAP than with FAP a t a bypass ratio of 50% or higher. CSF was higher with SAP than with F AP at a bypass ratio of 50% or higher. The coronary arteriovenous O-2 content difference was lower with SAP than with FAP at a bypass ratio of 85% or higher. In conclusion, at a high bypass ratio, SAP was more effective than FAP in achieving diastolic augmentation, thus enhancing myocardial oxygen balance, even though SAP had less of a systolic unl oading effect. These data support the use of SAP over FAP in patients with severe cardiopulmonary dysfunction requiring high-flow bypass, an d especially in patients with myocardial ischemia.