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CHAN Ngai-yin CHOY Chi-chung CHEUNG Kar-chun LAU Chun-leung LO Ying-keung CHU Pui-shan YUEN Ho-chuen LAU Suet-ting CHOI Yuen-choi 《中华医学杂志(英文版)》2010,123(13):1645-1651
Background Cardiac resynchronization therapy (CRT) is an effective electrical therapy for patients with moderate to severe heart failure and cardiac dyssynchrony. This study aimed to investigate the degree of acute left ventricular (LV) resynchronization with biventricular pacing (BVP) at different LV sites and to examine the feasibility of performing transthoracic echocardiography (TTE) to quantify acute LV resynchronization during CRT procedure. Methods Fourteen patients with NYHA Class Ⅲ-Ⅳ heart failure, LV ejection fraction 〈35%, QRS duration 〉120 ms and septal-lateral delay (SLD) 〉60 ms on tissue Doppler imaging (TDI), underwent CRT implant. TDI was obtained from three apical views during BVP at each accessible LV site and SLD during BVP was derived. Synchronicity gain index (Sg) by SLD was defined as (I+(SLD at baseline - SLD at BVP)/SLD at baseline). Results Seventy-two sites were studied. Positive resynchronization (R+, Sg〉1) was found in 42 (58%) sites. R+ was more likely in posterior or lateral than anterior LV sites (66% vs. 36%, P 〈0.001). Concordance of empirical LV lead implantation sites and sites with R+ was 50% (7/14). Conclusions The degree of acute LV resynchronizaUon by BVP depends on LV lead location and empirical implantation of LV lead results in only 50% concordance with R+. Performing l-rE during CRT implantation is feasible to identify LV sites with positive resynchronization. 相似文献
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本文针对二阶椭圆型常微分方程组边值问题提出二次超收敛有限体积元方法,证明格式的H1和L2模误差估计,并给出应力佳点处的梯度超收敛估计.最后,编写计算格式的Fortran程序,用数值算例验证了理论分析的正确性和格式的有效性. 相似文献
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一个新的边值问题和心外膜电位的唯一性 总被引:1,自引:0,他引:1
本文将心电位问题归结为一类新的边值问题,给出了该边值问题有解的一个必要条件,同时得到了求解心外膜电位的新的积分方程,证明了该积分方程解的唯一性。最后给出一个实例。 相似文献
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引用带权的Sobolev模和牛顿迭代格式,讨论了拟线性对称双曲抛物耦合方程组的初边值问题,得到了可微解的存在和唯一性定理。 相似文献
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本文研究多个自变量的拟线性对称双曲型方程组,在边界条件为非线性情况下的初边值问题。在一定的条件下,得到了可微解的存在和唯一性定理。 相似文献
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利用一个三阶两点边值问题的G reen函数和锥拉伸与锥压缩型的K rasnasel'sk ii不动点定理研究了一个非线性四阶边值问题正解存在性和多解性。描述了一端简单支撑,另一端活动的弹性梁的形变。结果表明:只要非线性项在某些有界集合上的“高度”是适当的,该问题至少有n个正解(n是一个任意的自然数) 相似文献
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考虑了二维空间上具超音速物理边界的可压Navier-Stokes方程的初边值问题.给定常数平衡态$(\rho^{\ast},0)$,得到了所考虑问题解的整体存在性. 在平衡态附近的小扰动下, 利用加权能量估计方法得到解的指数衰减性. 相似文献
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