Effects of Intra‐Aortic Balloon Pump Timing on Baroreflex Activities in a Closed‐Loop Cardiovascular Hybrid Model

Abstract

Despite 50 years of research to assess the intra-aortic balloon pump (IABP) effects on patients' hemodynamics, some issues related to the effects of this therapy are still not fully understood. One of these issues is the effect of IABP, its inflation timing and duration on peripheral circulation autonomic controls. This work provides a systematic analysis of IABP effects on baroreflex using a cardiovascular hybrid model, which consists of computational and hydraulic submodels. The work also included a baroreflex computational model that was connected to a hydraulic model with a 40-cm(3) balloon. The IABP was operated at different inflation trigger timings (-0.14 to 0.31 s) and inflation durations (0.05-0.45 s), with time of the dicrotic notch being taken as t = 0. Baroreflex-dependent parameters-afferent and efferent pathway activity, heart rate, peripheral resistance, and venous tone-were evaluated at each of the inflation trigger times and durations considered. Balloon early inflation (0.09 s before the dicrotic notch) with inflation duration of 0.25 s generated a maximum net increment of afferent pathway activity of 10%, thus leading to a decrement of efferent sympathetic activity by 15.3% compared with baseline values. These times also resulted in a reduction in peripheral resistance and heart rate by 4 and 4.3% compared with baseline value. We conclude that optimum IABP triggering time results in positive effects on peripheral circulation autonomic controls. Conversely, if the balloon is not properly timed, peripheral resistance and heart rate may even increase, which could lead to detrimental outcomes.

A new hybrid (hydro-numerical) model of the circulatory system

“…It should be considered that this version of the hybrid model does not include baroreflex and sympathetic feedbacks. However, the modular structure of the platform makes it possible to include these mechanisms in the model according to experimental needs and first steps in this direction have already been made [31].…”

Circulatory Modelling as a Clinical Decision Support and an Educational Tool

“…23 Finally, the modelling platform can be connected to physical or computational mechanical heart assist devices: they include continuous or pulsatile flow devices and intra aortic balloon pump. 19,25 The data storing procedure and content of the generated files will be described in the next paragraph.…”

Reproduction of Continuous Flow Left Ventricular Assist Device Experimental Data by Means of a Hybrid Cardiovascular Model With Baroreflex Control

“…SR was then divided among the main circulatory branches to assure a distribution of total CO as follows: upper body 23%, kidney 22%, splanchnic 30%, and lower body 25% (further details in ). Parameters obtained from this procedure are listed in Table .…”

“…It is a lumped parameter model developed in LabVIEW, mainly described in . It consists of left and right hearts: ventricular systole is described according to Starling's mechanism using a variable elastance model while the filling phase is reproduced using a series of exponential functions ; pulmonary circulation: the arterial section is described by a Windkessel model.…”

“…The HCS was developed at the Nałęcz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences in cooperation with the Institute of Clinical Physiology of the National Research Council. A baroreflex control submodel described in was added to the HCS to reproduce and analyze the effects of LVAD onset on hemodynamic parameters as heart rate (HR) and peripheral resistances.…”