Effective Left Ventricular Unloading by Transaortic Catheter Venting During Cardiopulmonary Bypass : Assessment of LV Energy Charge

Insufficient unloading of the left ventricle (LV) with blood stagnation is a limitation of percutaneous cardiopulmonary support (PCPS). The purpose of this study was to evaluate the effect of transaortic catheter venting (TACV; by a 6 Fr. pigtail catheter) for LV unloading with venoarterial bypass (VAB). Eleven adult mongrel dogs (12～20 kg) underwent VAB with TACV. Bypass flow ranged from 0.8～1.2 L/min and TACV flow ranged from 160～240 ml/min. With standard hemodynamic monitoring, the slope of the LV end-systolic pressure-volume relationship (Emax), aortic elastance (Ea), LV stroke work (SW), preload recruitable stroke work (PRSW) , LV pressure-volume area (PVA) and potential energy (PE) were assessed using a micro-tip manometer and a conductance catheter in each condition (baseline, VAB, VAB with TACV). The TACV combined support significantly reduced LV total energy (PVA) and LV work (SW) in comparison with the baseline levels and VAB. The LV energy charge ratio (PE/PVA) was significantly increased by TACV (27.8 ± 2.4%→37.6 ± 2.6%: p