Abstract 15773: The Forgotten Ventricle: Insight Into Dynamic Effects of Left Ventricular Assist Device Ramp on Right Ventricle Function

Abstract

Introduction: Left ventricular assist devices (LVAD) with magnetically levitated impellers have become standard due to hemocompatibility and survival profile. To optimize LVAD speeds, we previously introduced simultaneous right and left heart (RH/LH) catheterization during ramp studies. Here, we report pairing of this approach with pressure-volume (PV) assessment in a patient with a HeartMate 3 LVAD with mitral regurgitation (MR). The combined approach evaluated left ventricular (LV) hemodynamics and right ventricular (RV) PV-relationships during ramp testing. Methods: A 68-year-old male with ischemic cardiomyopathy, two years following HeartMate3 implantation, presented with NYHA class III symptoms. To evaluate for dyspnea, he underwent a RH/LH catheterization ramp study. RV PV-loops were created by use of a conductance catheter system, allowing creation of PV loops. Results: At the baseline LVAD speed of 5300 rotations per minute (RPM), right atrial pressure was elevated at 16 mmHg and pulmonary artery (PA) pressure of 26 mmHg. Left-end diastolic pressure (LVEDP) was elevated (16mmHg). Baseline cardiac index (CI) was 2.01 L/min/m 2 . Ramp testing was performed, increasing speeds from 5300 to 5800 RPM. Progressive LV unloading was observed with a 5 mmHg drop in LVEDP and a 3 mmHg drop in PA pressure. However, RV PV loop monitoring revealed a negative impact on RV contractility with the maximal elastance (Emax) slope demonstrating a 22% reduction. Furthermore, a 17% reduction in RV stroke volume was documented, while diastolic function remained unchanged. Thus, despite excellent LV offloading and diminishment of RV afterload, the significant negative impact on Emax resulted in no net increase in CI (+0.04 L/min/m 2 ) during the ramp evaluation. Inotrope therapy was initiated for RV function with increased LVAD RPM to outcompete MR. Conclusions: While RH/LH catheterization provides a real-time perspective of the interventricular relationship during ramp, the impact of increasing LVAD speeds on RV function has yet to be directly measured. Here, the RV PV loop relationship during LVAD ramp showed that although LVAD speed increases in the setting of MR may facilitate LV unloading, a drop in RV afterload did not compensate for reduction in RV contractility.