Patel Sunil, Wang Shigang, Pauliks Linda, Chang Dennis, Clark Joseph B, Kunselman Allen R, Ündar Akif
Department of Pediatrics, Penn State Hershey Pediatric Cardiovascular Research Center, Penn State Hershey College of Medicine, Hershey, PA, USA.
Artif Organs. 2015 Jan;39(1):67-76. doi: 10.1111/aor.12454.
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.
心律失常是体外生命支持（ECLS）期间常见的并发症。一种新型ECLS系统可根据心电图（ECG）的R波提供与患者自身心动周期同步的搏动血流。目前尚不清楚心律失常的发生如何改变该系统的血流动力学性能。这项体外研究评估了模拟心律失常对R波触发的搏动性ECLS期间血流动力学的影响。使用配备i-cor对角泵和iLA膜式呼吸机的ECLS回路在室温下用全血预充。使用定制的数据采集系统，在每种情况下以2.5和4升/分钟的流速收集流量和压力数据。搏动性ECLS血流通过1:1、1:2和1:3的辅助比率与ECG模拟器的R波同步。测试的情况包括45和90次/分钟的窦性心律、室上性心动过速（SVT）、室性心动过速（VT）以及不规则心律，如心室颤动。正常窦性心律、SVT、VT、心房颤动、心房扑动和室性二联律的ECG信号以1:1、1:2和1:3的辅助比率成功触发了搏动模式。90次/分钟的规则心律产生了最佳的剩余血流能量（SHE）。对于SVT和VT，1:2的辅助比率在2.5升/分钟的流速下产生了具有最佳SHE的最大搏动血流波形。在4升/分钟时，无论心律失常情况如何，SHE均下降且压力降增加。不规则心律在较低的搏动频率下仍能产生足够的搏动波形。这项研究证明了在各种模拟节律期间使用新型ECG同步i-cor系统产生搏动性ECLS血流的可行性。搏动血流的最佳速率为90次/分钟。在不规则节律期间，较低的搏动频率是产生搏动血流更可靠的同步模式。
