Naito Noritsugu, Nishimura Takashi, Takewa Yoshiaki, Kishimoto Satoru, Date Kazuma, Umeki Akihide, Ando Masahiko, Ono Minoru, Tatsumi Eisuke
Department of Artificial Organs, National Cerebral and Cardiovascular Center, Research Institute, Osaka.
Department of Cardiac Surgery, Tokyo Metropolitan Geriatric Hospital.
Artif Organs. 2016 Nov;40(11):1039-1045. doi: 10.1111/aor.12702. Epub 2016 May 19.
Excessive left ventricular (LV) volume unloading can affect right ventricular (RV) function by causing a leftward shift of the interventricular septum in patients with mitral regurgitation (MR) receiving left ventricular assist device (LVAD) support. Optimal settings for the LVAD should be chosen to appropriately control the MR without causing RV dysfunction. In this study, we assessed the utility of our electrocardiogram-synchronized rotational speed (RS) modulation system along with a continuous-flow LVAD in a goat model of MR. We implanted EVAHEART devices after left thoracotomy in six adult goats weighing 66.4 ± 10.7 kg. Severe MR was induced through inflation of a temporary inferior vena cava filter placed within the mitral valve. We evaluated total flow (TF; the sum of aortic flow and pump flow [PF]), RV fractional area change (RVFAC) calculated by echocardiography, left atrial pressure (LAP), LV end-diastolic pressure (LVEDP), LV end-diastolic volume (LVEDV), and LV stroke work (LVSW) with a bypass rate (PF divided by TF) of 100% under four conditions: circuit-clamp, continuous mode, co-pulse mode (increased RS during systole), and counter-pulse mode (increased RS during diastole). TF tended to be higher in the counter-pulse mode. Moreover, RVFAC was significantly higher in the counter-pulse mode than in the co-pulse mode, whereas LAP was significantly lower in all driving modes than in the circuit-clamp condition. Furthermore, LVEDP, LVEDV, and LVSW were significantly lower in the counter-pulse mode than in the circuit-clamp condition. The counter-pulse mode of our RS modulation system used with a continuous-flow LVAD may offer favorable control of MR while minimizing RV dysfunction.
在接受左心室辅助装置（LVAD）支持的二尖瓣反流（MR）患者中，过度的左心室（LV）容量卸载可通过使室间隔向左移位来影响右心室（RV）功能。应选择LVAD的最佳设置，以在不引起RV功能障碍的情况下适当控制MR。在本研究中，我们在MR山羊模型中评估了我们的心电图同步转速（RS）调制系统与连续流LVAD的效用。我们对6只体重66.4±10.7 kg的成年山羊进行左胸开胸手术后植入EVAHEART装置。通过在二尖瓣内放置临时下腔静脉滤器充气诱导严重MR。我们在四种情况下评估了总流量（TF；主动脉流量与泵流量[PF]之和）、通过超声心动图计算的RV分数面积变化（RVFAC）、左心房压力（LAP）、LV舒张末期压力（LVEDP）、LV舒张末期容积（LVEDV）和LV搏功（LVSW），旁路率（PF除以TF）为100%：回路钳夹、连续模式、共搏模式（收缩期RS增加）和反搏模式（舒张期RS增加）。反搏模式下TF往往更高。此外，反搏模式下RVFAC显著高于共搏模式，而在所有驱动模式下LAP均显著低于回路钳夹状态。此外，反搏模式下LVEDP、LVEDV和LVSW显著低于回路钳夹状态。我们的RS调制系统与连续流LVAD一起使用的反搏模式可能在最小化RV功能障碍的同时对MR提供良好的控制。
