Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan.
Am J Physiol Heart Circ Physiol. 2012 Apr 1;302(7):H1481-91. doi: 10.1152/ajpheart.00551.2011. Epub 2012 Jan 6.
Wave intensity analysis (WIA) was used to delineate and maximize the efficacy of a newly developed para-aortic blood pump (PABP). The intra-aortic balloon pump (IABP) was employed as the comparison benchmark. Acute porcine experiments using eight pigs, randomly divided into IABP (n = 4) and PABP (n = 4) groups, were conducted to compare the characteristics of intra- and para-aortic counterpulsation. We measured pressure and velocity with probes installed in the left anterior descending coronary artery and aorta, during and without PABP assistance. Wave intensity for aortic and left coronary waves were derived from pressure and flow measurements with synchronization correction applied. To achieve maximized support efficacy, deflation timings ranging from 25 ms ahead of to 35 ms after the R-wave were tested. Similar to those associated with IABP counterpulsation, the PABP-generated backward-traveling waves predominantly drove aortic and coronary blood flows. However, in contrast with IABP counterpulsation, the nonocclusive nature of the PABP allowed systolic unloading to be delayed into early systole, which resulted in near elimination of coronary blood steal without diminution of systolic left ventricular ejection wave intensities. WIA can elucidate subtleties among different counterpulsatile support means with high sensitivity. Total accelerating wave intensity (TAWI), which was defined as the sum of the time integration of accelerated parts of the positive and negative wave intensities, was used to quantify counterpulsation efficacy. In general, the larger the TAWI gain, the better the counter-pulsatile support efficacy. However, when PABP deflation timings were delayed to after the R-wave, the TAWI was found to be inversely correlated with coronary perfusion. In this delayed deflation timing setting, greater wave cancellation occurred, which led to decreased TAWI but increased coronary perfusion attributed to blood regurgitation reduction.
波强分析（WIA）用于描绘和最大化新开发的腹主动脉血泵（PABP）的疗效。将主动脉内球囊泵（IABP）作为比较基准。采用 8 头猪进行急性猪实验，随机分为 IABP（n=4）和 PABP（n=4）组，比较主动脉内和腹主动脉反搏的特征。我们在左前降支冠状动脉和主动脉内置入探头，测量 PABP 辅助和不辅助时的压力和速度。应用同步校正从压力和流量测量中推导出主动脉和左冠状动脉波的波强。为了实现最大支持效果，测试了从 R 波前 25ms 到后 35ms 的放气时间。与 IABP 反搏相关的波类似，PABP 产生的逆行波主要驱动主动脉和冠状动脉血流。然而，与 IABP 反搏不同，PABP 的非闭塞性质允许将收缩卸载延迟到早期收缩期，从而消除了冠状动脉窃血，而不会减弱收缩期左心室射血波强度。WIA 可以用高灵敏度阐明不同搏动性支持手段之间的细微差别。总加速波强（TAWI）定义为正、负波强加速部分的时间积分之和，用于量化反搏效果。一般来说，TAWI 增益越大，反搏支持效果越好。然而，当 PABP 放气时间延迟到 R 波后时，发现 TAWI 与冠状动脉灌注呈反比关系。在这种延迟放气时间设置中，发生了更大的波抵消，导致 TAWI 降低，但由于血液反流减少，冠状动脉灌注增加。
