Haemodynamic Effect of Left Atrial and Left Ventricular Cannulation with a Rapid Speed Modulated Rotary Blood Pump During Rest and Exercise: Investigation in a Numerical Cardiorespiratory Model.

Abstract

The left atrium and left ventricle are the primary inflow cannulation sites for heart failure patients supported by rotary blood pumps (RBPs). Haemodynamic differences exist between inflow cannulation sites and have been well characterized at rest, yet the effect during exercise with the same centrifugal RBP has not been previously well established. The purpose of this study was to investigate the hemodynamic effect of inflow cannulation site during rest and exercise with the same centrifugal RBP. In a numerical cardiorespiratory model, a simulated heart failure patient was supported by a HeartWare HVAD RBP in left atrial (LAC) and left ventricular cannulation (LVC). The RBP was operated at constant speed and sinusoidal co- and counter-pulse and was investigated in cardiovascular conditions of steady state rest and 80-watt bike graded exercise. Cardiac output was 5.0 L min-1 during rest and greater than 6.9 L min-1 during exercise for all inflow cannulation sites and speed operating modes. However, during exercise, LAC demonstrated greater pressure-volume area and lower RBP flow (1.41, 1.37 and 1.37 J and 5.03, 5.12 and 5.03 L min-1 for constant speed and co- and counter-pulse respectively) when compared to LVC (pressure-volume area: 1.30, 1.27 and 1.32 J and RBP flow: 5.56, 5.71 and 5.59 L min-1 for constant speed and co- and counter-pulse respectively). For a simulated heart failure patient intending to complete exercise, LVC seems to assure a better hemodynamic performance in terms of pressure-volume area unloading and increasing RBP flow.