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 cardiopulmonary resuscitation. This experimental study examines whether coronary perfusion and hemodynamics are affected by the site of the blood supply, comparing the subclavian artery and the femoral artery. VAB and IABP were performed in 11 mongrel dogs with cardiopulmonary failure induced by acute myocardial infarction and hypoventilation. Aortic root pressure (AP), left atrial pressure, central venous pressure and coronary sinus blood flow (CSF) were measured, and blood gas analysis was performed. Subclavian artery perfusion (SAP) and femoral artery perfusion (FAP) were compared at bypass ratios of 25, 50, 75, 85, 100%. At bypass ratios of 75% and 85% the mean systolic AP was higher with SAP than with FAP. The mean diastolic AP was higher with SAP than with FAP at a bypass ratio of 50% or higher. CSF was higher with SAP than with FAP at a bypass ratio of 50% or higher. The coronary arteriovenous O2 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 unloading effect. These data support the use of SAP over FAP in patients with severe cardiopulmonary dysfunction requiring high-flow bypass, and especially in patients with myocardial ischemia.