Recovery From Exhaustion of the Frank-Starling Mechanism by Mechanical Unloading With a Continuous-Flow Ventricular Assist Device

Abstract

Background:We describe our original left ventricular assist device (LVAD) speed ramp and volume loading test designed to evaluate native heart function under continuous-flow LVAD support. Methods and Results:LVAD speed was decreased in 4 stages from the patient’s optimal speed to the minimum setting for each device. Under minimal LVAD support, patients were subjected to saline loading (body weight [kg]×10 mL in 15 min). Echocardiographic and hemodynamic data were obtained at each stage of the LVAD speed ramp and every 3 min during saline loading. Patients were divided into Recovery (with successful LVAD removal; n=8) and Non-recovery (others; n=31) groups. During testing, increased pulmonary capillary wedge pressure caused by volume loading was milder in the Recovery than Non-recovery group (repeated measures analysis of variance; group effect, P=0.0069; time effect, PConclusions:The LVAD speed ramp and volume loading test facilitates the precise evaluation of native heart function during continuous-flow LVAD support.