Shimamura Junichi, Nishimura Takashi, Mizuno Toshihide, Takewa Yoshiaki, Tsukiya Tomonori, Inatomi Ayako, Ando Masahiko, Umeki Akihide, Naito Noritsugu, Ono Minoru, Tatsumi Eisuke
Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1, Fujishirodai, Suita, Osaka, 565-8565, Japan.
Department of Cardiac Surgery, University of Tokyo, Tokyo, Japan.
J Artif Organs. 2019 Dec;22(4):269-275. doi: 10.1007/s10047-019-01109-3. Epub 2019 Jun 15.
Under continuous-flow left ventricular assist device (CF-LVAD) support, the ventricular volume change and cardiac cycle between the left ventricle (LV) and right ventricle (RV) become dyssynchronous due to the shortening of the LV systole. The purpose of this study was to quantify interventricular dyssynchrony based on different CF-LVAD support conditions and assess its relationship with LV unloading. In this study, we evaluated seven goats (body weight 44.5 ± 6.5 kg) with normal hearts. A centrifugal LVAD was implanted under general anesthesia. We inserted the conductance catheters into the left ventricle (LV) and right ventricle (RV) to assess the volume signal simultaneously. We defined the interventricular dyssynchrony as a signal (increase or decrease) of LV volume (LVV) change opposite to that of RV volume (RVV) (i.e., (dLVV/dt) × (dRVV/dt) < 0). The duration of interventricular dyssynchrony (DYS) was reported as the percentage of time that a heart was in a dyssynchronous state within a cardiac cycle. The mean DYS of normal hearts, hearts with LVAD clamp and hearts supported by LVADs with a bypass rate of 50%, 75% and 100% were 5.6 ± 1.6%, 8.7 ± 2.4%, 8.6 ± 2.8%, 15.1 ± 5.1%, and 25.6 ± 8.0%, respectively. Furthermore, the DYS was found to be associated with the degree of LV stroke volume reduction caused by LV unloading. These findings may be useful for understanding interventricular interactions and physiology during CF-LVAD support. Influences on the right ventricular function and heart failure models warrant further study.
在持续血流左心室辅助装置（CF-LVAD）支持下，由于左心室（LV）收缩期缩短，左心室和右心室（RV）之间的心室容积变化和心动周期变得不同步。本研究的目的是基于不同的CF-LVAD支持条件量化心室间不同步，并评估其与左心室卸载的关系。在本研究中，我们评估了7只心脏正常的山羊（体重44.5±6.5千克）。在全身麻醉下植入离心式LVAD。我们将电导导管插入左心室（LV）和右心室（RV）以同时评估容积信号。我们将心室间不同步定义为左心室容积（LVV）变化与右心室容积（RVV）变化相反的信号（增加或减少）（即，(dLVV/dt)×(dRVV/dt)<0）。心室间不同步的持续时间（DYS）报告为心脏在心动周期内处于不同步状态的时间百分比。正常心脏、LVAD夹闭心脏以及旁路率为50%、75%和100%的LVAD支持心脏的平均DYS分别为5.6±1.6%、8.7±2.4%、8.6±2.8%、15.1±5.1%和25.6±8.0%。此外，发现DYS与左心室卸载导致的左心室每搏量减少程度相关。这些发现可能有助于理解CF-LVAD支持期间的心室间相互作用和生理学。对右心室功能和心力衰竭模型的影响值得进一步研究。
