Mechanical Circulatory Support for Biventricular Heart Failure Using Advanced Ventricular Assist Device

Abstract

In patients with severe biventricular heart failure (HF) and cardiogenic shock, use of biventricular assist device (BVAD) can be a treatment of choice. We are developing an advanced ventricular assist device (AVAD) intended to serve as universal pump for left and/or right heart failure (Fig.1 A,B). The purpose of this initial in silico simulation study was to demonstrate that AVAD design can be suitable for biventricular support. The virtual mock loop (VML) was developed (MATLAB; MathWorks®) to simulate hemodynamic parameters as they surge through the BVAD-supported systolic HF cardiovascular system. The AVAD used as in BVAD configuration was in 2 speeds (3400 rpm left, 2000 rpm right) to get comparable systemic flow and pressure outputs. LVAD support was adjusted to maintain 5.0 L/min total systemic flow. For BVAD, the added RVAD support was adjusted to maintain left and right atrial pressure (LAP-RAP) at 3-5 mm Hg. The BVAD performance was maintained very well for both left ventricular (L-AVAD) and right ventricular (R-AVAD) support within specified speed range (Fig1 C,D). L- AVAD speed of 3000 - 3500 rpm provided sufficient support for the case of severe left and right systolic heart failure, assuming there was no aortic valve regurgitation. At the simulated condition, with L-AVAD support, the aortic valve remains closed and the systemic pressure has reduced pulse. A stable hemodynamics were maintained. The atrial pressure difference (LAP-RAP) resulted to be sensitive to the right pump speed, though was balanced whenever there was any positive flow through the pulmonary valve. Introduction of R-AVAD support to the L-AVAD support caused the left atrial pressure to increase resulting in increased filling of the left ventricle and a corresponding increase in aortic pulsatility. These initial in silico study demonstrated that use of the universal AVAD as BVAD supports cardiac output and arterial pressure in biventricular HF condition.