Objective: To compare the efficacy of a new intraaortic propeller pump (PP) to provide hemodynamic support to the intraaortic balloon pump (IABP) in an acute mitral regurgitation (MR) animal model.
Background: A new intraaortic PP (Reitan catheter pump; Jomed; Helsingborg, Sweden) recently has been introduced. The pump's aim is a reduction in afterload via a deployable propeller that is placed in the high descending aorta and can be set at rotational speeds of <or= 14,000 revolutions per minute (rpm).
Methods: In nine calves, acute MR was created by placing a vena cava filter in the mitral valve. The PP was tested at 6,000, 10,000, and 14,000 rpm and was compared to 1:1 IABP support. Cardiac output, coronary blood flow, carotid artery flow, ascending and abdominal aortic pressure, left atrial pressure, and LV pressure-volume loops were recorded.
Results: The PP caused an rpm-dependent reduction in the mean ascending aortic pressure reaching -10 mm Hg (p < 0.05) at 14,000 rpm. However, mean (+/- SD) cardiac output did not improve (2.6 +/- 0.7 to 2.5 +/- 1.1 L/min; p = not significant), and mean diastolic coronary flow and carotid flow (47 +/- 16 to 35 +/- 15 centiliters/min, p < 0.05) were reduced. The IABP improved cardiac output, and carotid and diastolic coronary flow.
Conclusions: In this acute MR animal model, the PP reduced afterload but left out positive effects on cardiac output, which resulted in reduced perfusion of the upper body and the coronary circulation. Therefore, the IABP gives better hemodynamic support than the new PP in calves with acute MR.