What Is the Optimal Setting for a Continuous-Flow Left Ventricular Assist Device in Severe Mitral Regurgitation?
What Is the Optimal Setting for a Continuous-Flow Left Ventricular Assist Device in Severe Mitral Regurgitation?
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DOI：
10.1111/aor.12702
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发表时间：
2016-11-01
影响因子：
2.4
通讯作者：
Tatsumi, Eisuke
中科院分区：
文献类型：
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作者：
Naito, Noritsugu;Nishimura, Takashi;Tatsumi, Eisuke
在接受左心室辅助装置(LVAD)支持的二尖瓣反流(MR)患者中，过多的左心室(LV)容量卸载可通过导致室间隔左移而影响右室(RV)功能。应选择LVAD的最佳设置，以适当控制MR，而不会导致RV功能障碍。在这项研究中，我们评估了我们的心电图同步转速(RS)调制系统和连续血流LVAD在MR山羊模型中的应用。我们在6只体重66.4+/-10.7公斤的成年山羊身上植入了左开胸术后的EVAHEART装置。严重的MR是通过充气放置在二尖瓣内的临时下腔静脉滤器来诱导的。我们在四种条件下评估总流量(Tf；主动脉流量和泵流量之和[Pf])、右室面积变化分数(RVFAC)、左房压(LAP)、左室舒张末压(LVEDP)、左室舒张末容量(LVEDV)和左每搏做功(LVSW)，其中旁路率(PF除以Tf)为100%：电路钳制、连续模式、同脉冲模式(收缩期间RS增加)和反脉冲模式(舒张期RS增加)。在反脉冲模式下，Tf趋于较高。此外，RVFAC在反脉冲模式下显著高于共脉冲模式，而LAP在所有驱动模式下显著低于电路钳位条件下。此外，在反脉冲模式下，LVEDP、LVEDV和LVSw显著低于电路钳制条件下。我们的RS调制系统的反脉冲模式与连续流LVAD一起使用，可以提供良好的MR控制，同时将RV功能障碍降至最低。
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.