双心室起搏-不应期电刺激的急性血液动力学变化和计算机仿真研究  

A computer simulation study of acute homodynamic changes of biventricular pacing in patients with sick sinus syndrome and its ionic mechanism

作　　者：舒娟[1] 王东琦[1] 金印彬[1] 杨琳[1] 薛小临[1] 马奕[1] 苏显明[1] 赵小静[2] 崔长琮[1] 

机构地区：[1]西安交通大学医学院第一附属医院心内科,陕西西安710061 [2]西安交通大学医学院第二附属医院心内科,陕西西安710004

出　　处：《西安交通大学学报（医学版）》2009年第2期185-188,共4页Journal of Xi’an Jiaotong University（Medical Sciences）

摘　　要：目的观察双心室起搏对病态窦房结综合征(sick sinus syndrome,SSS)患者的急性血液动力学变化及心脏绝对不应期电刺激对心功能的影响,通过计算机仿真研究,探讨绝对不应期电刺激的离子流作用机制。方法对10例SSS患者经冠状静脉左室后外侧支和右心室心尖部进行双心室起搏,通过漂浮导管观察起搏前后5 min的血流动力学和心电图变化的指标。应用计算机仿真技术,观察心脏绝对不应期电刺激前后钙浓度的变化。结果双心室起搏时,心脏每分输出量(cardiac output,CO)、心脏排血指数(cardiac index,CI)分别增加16.2%、16.8%,肺毛细血管嵌压(pulmonary capillary wedge pressure,PCWP)下降,跨室壁复极离散度(transmural dispersion of repolarization,TDR)变小,绝对不应期电刺激使仿真的心室肌细胞在绝对不应期正向波刺激,可明显增加Ca2+内流。结论双心室起搏可增加心肌收缩功能,减小跨室壁复极离散度。心脏绝对不应期电刺激可触发电压依赖性钙通道开放,使心肌钙浓度增加,增强衰竭心室肌细胞的收缩功能。Objective To observe the acute homodynamic changes of biventricular pacing （BivP） in patients with sick sinus syndrome （SSS） and investigate the Ca^2＋ changes during absolute refractory period electrical stimulation （ARPES） by applying computer simulation. Methods The hemodynamic parameters and ECG changes were measured in ten SSS patients five minutes before and after BivP connecting RVA and LVB. The extent of contraction and Ca^2＋ transient （Ca-T） changes during ARPES were recorded through computer simulation. Results During BivP cardiac output per minute and cardiac index increased by 16.2% and 16.8%, respectively. In contrast, pulmonary capillary wedge pressure and transmural dispersion of repolarization decreased. The inward calcium current was increased by applying repolarization stimulation during ARPES. Conclusion Appropriate biventricular pacing may strengthen contractility and decrease transmural dispersion of repolarization. ARPES can trigger voltage-dependent calcium channel to open, thus increasing inward calcium current and contractility of myocytes in failure ventricles.

关 键 词：双心室起搏 绝对不应期电刺激 心脏再同步治疗 钙浓度 计算机仿真 

分 类 号：R318.11[医药卫生—生物医学工程]