Kolyva Christina, Pantalos George M, Pepper John R, Khir Ashraf W
1 Brunel Institute for Bioengineering, Brunel University, Uxbridge - UK.
Int J Artif Organs. 2015 Mar;38(3):146-53. doi: 10.5301/ijao.5000385. Epub 2015 Mar 1.
The intra-aortic balloon pump (IABP) provides circulatory support through counterpulsation. The hemodynamic effects of the IABP may vary with assisting frequency and depend on IAB inflation/deflation timing. We aimed to assess in vivo the IABP benefits on coronary, aortic, and left ventricular hemodynamics at different assistance frequencies and trigger timings.
Six healthy, anesthetized, open-chest sheep received IABP support at 5 timing modes (EC, LC, CC, CE, CL, corresponding to early/late/conventional/conventional/conventional inflation and conventional/conventional/conventional/early/late deflation, respectively) with frequency 1:3 and 1:1. Aortic (Q(ao)) and coronary (Q(cor)) flow, and aortic (P(ao)) and left ventricular (PLV) pressure were recorded simultaneously, with and without IABP support. Integrating systolic Q(ao) yielded stroke volume (SV).
EC at 1:1 produced the lowest end-diastolic P(ao) (59.5 ± 7.8 mmHg [EC], 63.4 ± 11.1 mmHg [CC]), CC at 1:1 the lowest systolic PLV (69.1 ± 6.5 mmHg [CC], 76.4 ± 6.5 mmHg [control]), CC at 1:1 the highest SV (88.5 ± 34.4 ml [CC], 76.6 ± 31.9 ml [control]) and CC at 1:3 the highest diastolic Qcor (187.2 ± 25.0 ml/min [CC], 149.9 ± 16.6 ml/min [control]). Diastolic P(ao) augmentation was enhanced by both assistance frequencies alike, and optimal timings were EC for 1:3 (10.4 ± 2.8 mmHg [EC], 6.7 ± 3.8 mmHg [CC]) and CC for 1:1 (10.8 ± 6.7 mmHg [CC], -3.0 ± 3.8 mmHg [control]).
In our experiments, neither a single frequency nor a single inflation/deflation timing, including conventional IAB timing, has shown superiority by uniformly benefiting all studied hemodynamic parameters. A choice of optimal frequency and IAB timing might need to be made based on individual patient hemodynamic needs rather than as a generalized protocol.
主动脉内球囊反搏（IABP）通过反搏提供循环支持。IABP的血流动力学效应可能随辅助频率而变化，并取决于球囊充气/放气时间。我们旨在评估在不同辅助频率和触发时间下，IABP对冠状动脉、主动脉和左心室血流动力学的体内益处。
六只健康、麻醉、开胸的绵羊在5种时间模式（EC、LC、CC、CE、CL，分别对应早期/晚期/传统/传统/传统充气和传统/传统/传统/早期/晚期放气）下接受IABP支持，频率为1:3和1:1。在有和没有IABP支持的情况下，同时记录主动脉（Q(ao)）和冠状动脉（Q(cor)）血流，以及主动脉（P(ao)）和左心室（PLV）压力。对收缩期Q(ao)进行积分得出每搏输出量（SV）。
1:1时的EC产生最低的舒张末期P(ao)（59.5±7.8 mmHg [EC]，63.4±11.1 mmHg [CC]），1:1时的CC产生最低的收缩期PLV（69.1±6.5 mmHg [CC]，76.4±6.5 mmHg [对照组]），1:1时的CC产生最高的SV（88.5±34.4 ml [CC]，76.6±31.9 ml [对照组]），1:3时的CC产生最高的舒张期Qcor（187.2±25.0 ml/min [CC]，149.9±16.6 ml/min [对照组]）。两种辅助频率均同样增强了舒张期P(ao)的增加，1:3时的最佳时间为EC（10.4±2.8 mmHg [EC]，6.7±3.8 mmHg [CC]），1:1时的最佳时间为CC（10.8±6.7 mmHg [CC]，-3.0±3.8 mmHg [对照组]）。
在我们的实验中，无论是单一频率还是单一充气/放气时间，包括传统的IAB时间，都没有通过统一有益于所有研究的血流动力学参数而显示出优势。可能需要根据个体患者的血流动力学需求而不是作为通用方案来选择最佳频率和IAB时间。
