Key result
Synchronous counterpulsation of continuous-flow LVADs reduced ventricular unloading indexes, while low-frequency asynchronous patterns increased vascular pulsatility in a numerical model.
Why the study?
CFLVADs routinely operate at constant speed, decreasing arterial pulsatility and potentially causing late complications, making speed modulation a potential solution to enhance pulsatility.
In a numerical model, synchronous counterpulsation CFLVAD speed modulation improved ventricular unloading, while low-frequency asynchronous modulation enhanced vascular pulsatility.
Answers are grounded in this paper and cite their sources.
Numerical models support testing LVAD speed modulation; leaves open optimal patterns for clinical unloading versus pulsatility.
Continuous-flow left ventricular assist devices (CFLVADs) routinely operate at a constant speed for the support of a failing heart, which decreases the pulsatility in the arteries. Some late complications could be related to a long-term lack of pulsatility. Modulating the CFLVAD speed is a solution to enhance the pulsatility. The purpose of this study is to modulate multiple varying speed patterns and investigate their effects on the ventricle and vascular system. A cardiovascular coupling numerical model is developed to provide a simulation platform for testing the varying speed patterns. The varying speed patterns are modulated by combining the shape, amplitude, frequency, phase shift, and pulsatile duty cycle of the speed profile. The influence of varying speed support is examined by analyzing the indexes of pulsatility, indexes of ventricular unloading, and hemodynamic variables. The results show that the synchronous counterpulsation pattern can effectively reduce the ventricular unloading indexes, whereas the low-frequency asynchronous pattern can effectively increase the vascular pulsatility indexes. Also, the hemodynamics with synchronous varying speed support is more physiological than that with asynchronous varying speed support. This study provides valuable insight for further optimization of varying speed modulation by weighing vascular pulsatility, ventricular unloading, and hemodynamics.
No takes yet. Share an insight, caveat, or question.
Liu et al. (2020) studied Heart failure requiring continuous-flow left ventricular assist device. Varying speed modulation of continuous-flow left ventricular assist device vs. Constant speed or other varying speed patterns was evaluated on Indexes of pulsatility, indexes of ventricular unloading, and hemodynamic variables. Synchronous counterpulsation of continuous-flow LVADs reduced ventricular unloading indexes, while low-frequency asynchronous patterns increased vascular pulsatility in a numerical model.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: