FLOW VISUALIZATION IN A MOCK VENTRICLE SUPPORTED WITH A LEFT VENTRICULAR ASSIST DEVICE

Abstract

Purpose: Flow patterns were studied in a rigid transparent mock ventricle equipped with different left ventricular assist devices (LVADs) to detect vortical patterns, stagnation zones, and turbulence generated in the heart by clinically used LVADs. Methods: LVADs (Jarvik 2000 or HeartMate II) were connected to the apex of a rigid mock ventricle. Preload was kept constant at the level of the mitral orifice, through which dye was injected into the mock ventricle. Flow patterns were recorded with a digital video camera. Experiments were conducted at a range of Reynolds numbers (100 Q<5 L/min). The Reynolds number at pump inlet is defined as 4Q/πvd, where Q is measured pump flow rate, v is fluid kinematic viscosity, and d is pump inlet diameter. Results: At all Reynolds numbers studied, the Jarvik 2000 produced more mixing in the mock ventricle when compared to the HeartMate II. When a HeartMate II inlet cannula was placed upstream of the Jarvik 2000, ventricular flow patterns resembled those of the HeartMate II. Conclusions: The basic flow patterns created by different LVADs can be studied in a static ventricle. Flow visualization in a dynamic mock ventricle is in progress.Figure