血流向量成像技术评价右心室心尖起搏对左心室流场分布的影响

Influence of right ventricular apical pacing on left ventricular vortices with vector flow mapping

目的应用血流向量成像(VFM)技术显示左心室腔内的血液流场,探讨右心室心尖起搏状态下左心室腔内流场变化规律。方法选取14例因病态窦房结综合征植入双腔起搏器的患者(起搏组)及30例正常人(对照组)为观察对象,使用DAS-RS1软件获取左心室腔VFM涡流图像,测量等容收缩期与舒张中期主涡流的直径(横径Dx、纵径Dy)、涡流位置(横向Px、纵向Py)、涡流圈数、涡流中心数目、涡流最大向量速度(Vmax)及涡流持续时间。结果右心室心尖起搏组与对照组比较,等容收缩期和舒张中期左心室腔内主涡流直径变小,涡流圈数减少,涡流中心数目增加,最大向量速度减慢,涡流持续时间延长(P<0.05)。结论 VFM技术能直观显示、定量分析右心室心尖部起搏状态下左心室腔内流场分布。

Objective To evaluate the dynamic changes of intraventricular vortices in the patients with sick sinus syndrome（SSS） having right ventricular apical pacing with vector flow mapping （VFM）. Methods Fourteen patients with SSS were implanted with dual chamber pacemaker and thirty healthy subjects were assessed by conventional echocardiography. The vortex distribution in the left ventricle was obtained by VFM with the software of DAS-RS1. Series of vortex parameters were compared between the pacing group and the control group in the selected phases of cardiac cycle,including vortex diameter （transverse and vertical diameter）,vortex position （transverse and longitudinal position）,the number of vortex rings （number of ring）,the number of vortex cores （number of core）,vortex maximum flow velocity （Vmax） and vortex duration （T）. Results During the isovolumic contraction and the mid-diastole,right ventricular apical pacing was shown with smaller vortex diameter,decreased vortex rings,increased vortex cores,slower maximum vector velocity and prolonged duration of vortex （P0.05）. Conclusions VFM may provide a novel approach to assess the changes of intracardiac blood flow field in the pacing subjects.