Effectiveness of transaortic venting from a failing left ventricle during venoarterial bypass.

Insufficient unloading of the left ventricle (LV) is a limitation of percutaneous cardiopulumonary support (PCPS). We previously reported the unloading effect of transaortic catheter venting (TACV) during venoarterial bypass (VAB) in normal hearts. The aim of this study was to assess the effectiveness of TACV with VAB in a heart failure (HF) model. Seven adult mongrel dogs underwent TACV with VAB, and isolated LV failure was induced by multiple ligation of left coronary arteries. With standard hemodynamic monitoring, slope of the LV end-systolic pressure-volume relationship (Emax; mm Hg/ml), aortic elastance (Ea; mm Hg/ml), LV stroke work (SW; 10(-4)J), preload recruitable stroke work (PRSW; 10(-4)J/ ml), LV pressure-volume area (PVA; 10(-4)J), and potential energy (PE; 10(-4)J) were assessed using a micro-tip manometer and a conductance catheter. In addition to evaluation of LV function, myocardial adenosine 5'-triphosphate (ATP) was measured in each condition. The TACV combined support significantly reduced LV total energy (PVA) and LV work (SW). The LV energetic charge (PE/PVA, myocardial ATP) was significantly increased by TACV. These results suggest that TACV might be an effective technique for LV recovery during VAB or PCPS in patients with severe heart failure.