Evaluation of a Novel Pulsatile Extracorporeal Life Support System Synchronized to the Cardiac Cycle: Effect of Rhythm Changes on Hemodynamic Performance

Abstract

Arrhythmias are a frequent complication during extracorporeal life support (ECLS). A new ECLS system can provide pulsatile flow synchronized to the patient's intrinsic cardiac cycle based upon the R wave of the electrocardiogram (ECG). It is unclear how the occurrence of arrhythmias may alter the hemodynamic performance of the system. This in vitro study evaluated the effect of simulated arrhythmias on hemodynamics during R wave-triggered pulsatile ECLS. The ECLS circuit with an i-cor diagonal pump and iLA membrane ventilator was primed with whole blood at room temperature. Flow and pressure data were collected at 2.5 and 4 L/min for each condition using a customized data acquisition system. Pulsatile ECLS flow was R wave synchronized to an ECG simulator using 1:1, 1:2, and 1:3 assist ratios. Conditions tested included sinus rhythm at 45 and 90 bpm, supraventricular tachycardia (SVT), ventricular tachycardia (VT), and irregular rhythms such as ventricular fibrillation. Pulsatile mode was successfully triggered by ECG signals of normal sinus rhythm, SVT, VT, atrial fibrillation, atrial flutter, and ventricular bigeminy with assist ratios 1:1, 1:2, and 1:3. Regular rhythm at 90 bpm generated the best surplus hemodynamic energy (SHE). For SVT and VT, an assist ratio of 1:2 resulted in maximum pulsatile flow waveforms with optimal SHE at 2.5 L/min flow rate. At 4 L/min, SHE declined and the pressure drop increased independent of arrhythmia condition. Irregular rhythms still produced adequate pulsatile wave forms at lower pulsatile frequency. This study demonstrated the feasibility of generating pulsatile ECLS flow with the novel ECG-synchronized i-cor system during various simulated rhythms. The optimal rate for pulsatile flow was 90 bpm. During irregular rhythms, the lower pulsatile frequency was the more reliable synchronization mode for generating pulsatile flow.

In Vitro Evaluation of ECG‐Synchronized Pulsatile Flow Using the i‐cor Diagonal Pump in Neonatal and Pediatric ECLS Systems

“…While the Food and Drug Administration has not yet approved this pump for use in the United States (CE approved for nonpulsatile flow), the i‐cor pump holds significant clinical and research implications. Our group has evaluated the i‐cor system in vitro as well as in vivo, and confirmed its feasibility for adult ECLS . However, its feasibility is not yet clear for neonatal and pediatric ECLS.…”

“…The percent of THE lost across the arterial tubing increased with increasing pulsatility (P < 0.05), and the differences in THE lost were larger at lower flow rates (3.1-15.1% at 200 mL/min vs. 14. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].7% at 1600 mL/min). The percent of THE lost across the oxygenator was greater when using the pediatric Hilite 2400 LT oxygenator (20.0-24.6% at 1600 mL/min) rather than the neonatal Hilite 800 LT oxygenator (7.2-9.0% at 600 mL/min).…”

Impact of Pulsatility and Flow Rates on Hemodynamic Energy Transmission in an Adult Extracorporeal Life Support System

“…The novel i-cor circuit incorporates a new diagonal pump that can produce excellent pulsatility (17,21,22). The novel i-cor circuit incorporates a new diagonal pump that can produce excellent pulsatility (17,21,22).…”

“…The Medos Deltastream DP3 diagonal pump is already being clinically used in Europe (20), but is not currently approved by the Food and Drug Administration (FDA) in the United States. While ECG synchronization is its newest feature, the pump also aims to create satisfactory pulsatile and nonpulsatile flow in the ECLS circuit (17,21,22). While ECG synchronization is its newest feature, the pump also aims to create satisfactory pulsatile and nonpulsatile flow in the ECLS circuit (17,21,22).…”

“…The latest development in diagonal pumps is the i-cor diagonal pump, which has been developed with the ability to synchronize with the electrocardiogram (ECG) of a patient to trigger pulsatile flow. While ECG synchronization is its newest feature, the pump also aims to create satisfactory pulsatile and nonpulsatile flow in the ECLS circuit (17,21,22).…”