Key result
A constant stroke work control strategy for LVADs produced significantly more pronounced speed changes during load interventions compared to constant speed and work ratio controllers.
Why the study?
The physical fitness of patients with terminal heart failure and an implanted left ventricular assist device might be improved by load-adaptive control.
Does a constant stroke work control strategy improve LVAD load adaptation compared to work ratio or constant speed controllers in a porcine model of biventricular heart insufficiency?
Does a constant stroke work control strategy improve LVAD load adaptation compared to work ratio or constant speed controllers in a porcine model of biventricular heart insufficiency?
p-value: p=<0.001
A constant stroke work control strategy for LVADs provides more pronounced speed adaptation to load changes compared to constant speed or work ratio controllers in a porcine model.
CSW may enhance physiologic LVAD adaptation in porcine models; leaves open translation to clinical use.
The physical fitness of patients with terminal heart failure and an implanted left ventricular assist device (LVAD) might be improved by load-adaptive control of the LVAD. In this study, three control strategies for LVAD were compared in eight pigs: (1) a constant stroke work (CSW) control strategy that ensures a constant ventricular load using ventricular stroke work as the control variable; (2) a work ratio (WR) controller that maintains a constant ratio of ventricular work to hydraulic pump work; and (3) a controller that maintains the pump pace at a constant speed (CS). Biventricular heart insufficiency was induced by increased isoflurane application, and preload, afterload, and contractility alterations were performed. LVAD speed changes were significantly more pronounced in all load interventions with the CSW control strategy (preload: P < 0.001 vs. CS and P = 0.004 vs. WR; afterload: P < 0.001 vs. CS and P < 0.001 vs. WR; contractility: P < 0.001 vs. CS and P < 0.001 vs. WR). However, a significant difference in systemic flow only became evident in the experiments upon afterload increase ( P < 0.001 vs. CS and P = 0.004 vs. WR). An implementation of an evolved version of the CSW control strategy that dispenses with invasively measured parameters might be feasible for clinical use.
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A 2022 study studied Induced biventricular heart insufficiency (n=8). Constant stroke work (CSW) control strategy vs. Work ratio (WR) controller and constant speed (CS) controller was evaluated on LVAD speed changes and systemic flow during load interventions (p=<0.001). A constant stroke work control strategy for LVADs produced significantly more pronounced speed changes during load interventions compared to constant speed and work ratio controllers.
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