超声血流速度向量技术评价心脏房室顺序起搏患者舒张期左心室腔内能量损耗

The assessment of diastolic blood flow field related energy loss of left ventricle in patients with right heart dual-chamber pacing using ultrasonic vector flow mapping

目的 应用超声血流速度向量（VFM）技术评价心脏房室顺序起搏患者舒张期左心室腔内血流流场状态及变化,初步探讨其临床应用价值.方法 心脏房室顺序起搏组51例和对照组健康志愿者73例.在VFM模式下采集标准心尖两腔、三腔及四腔3个心动周期连续动态彩色多普勒血流图像,将VFM资料导入DAS-RSI超声工作站,脱机分析获得等容舒张期、舒张早期、舒张中期及舒张晚期左心室腔内能量损耗、涡旋面积和涡旋强度等参数,比较两组能量损耗、涡旋面积和涡旋强度的差异以及三者间的线性相关性.结果 与对照组相比,心脏房室顺序起搏组等容舒张期、舒张早期、舒张晚期左心室腔内能量损耗均明显增高（Z=-6.689,-5.683,-3.014,-4.418,P＜0.001）,舒张中期能量损耗减低（Z=-3.014,P＜0.05）;房室顺序起搏组涡旋强度在等容舒张期、舒张早期、舒张晚期明显大于对照组（t =2.388,2.988,3.153,P＜0.05）,舒张中期两组间差异无统计学意义（P＞0.05）.涡旋面积两组间差异无统计学意义（P＞0.05）.对照组和心脏房室顺序起搏组各时相能量损耗与涡旋面积、涡旋强度无线性相关;对照组舒张期各时相涡旋面积与涡旋强度均呈线性相关（r=0.396～0.809,P=0.003～0.000）,心脏房室顺序起搏组等容舒张期涡旋面积与涡旋强度呈线性相关.结论 心脏房室顺序起搏状态下,舒张期左心室腔内流体能量损耗明显增高、涡流分布明显异常;起搏组左心室腔内涡流强度明显增大,提示心脏房室顺序起搏患者舒张期左心室血液流体状态明显异常.起搏组舒张期涡旋面积与涡旋强度的失关联,可能是左室腔内血流能量损耗增加的原因之一.

Objective To assess the changes of diastolic blood flow field and energy loss of left intraventricular flow in patients with heart dual-chamber pacing using ultrasonic vector flow mapping（VFM）,and to explore the clinical value of VFM technology for the assessment of left ventricular diastolic function in patients with cardiac pacing.Methods After routine echocardiographic exam for 51 patients with dualchamber pacing as pacemaker group and 73 volunteers as control group,the color Doppler flow imagings from standard dynamic apical two,three and four-chamber views for 3 completed cardiac cycles were acquired in VFM mode,and were imported to DAS-RSI workstation subsequently.The off-line measurement of diastolic left intra-ventricular flow for prescription parameter,such as energy loss,vortex area and vortex intensity,was performed.The left intra-ventricular parameters of two groups were compared for difference,and the correlationship between parameters at isovolumetric,early,mid and late diastolic phases was analyzed with SPSS 17.0 statistical software.Results 1） The energy losses of pacemaker group compared with the those of control group were significantly higher at isovolumetric,early,and late diastolic phases （Z =-6.689,-5.683,-3.014,-4.418,P 〈 0.001）,and at mild-diastole,energy loss was reduced mildly（Z =-3.014,P 〈0.05）.2） Vortical intensity of pacemaker group was significantly greater than that of the control group in isovolumic,early and late diastolic phases （t =2.388,2.988,3.153,P 〈0.05） separately,there was not statistically vertical intensity differences in mid-diastole between the two groups and no significant vortical area difference between the two groups.3） There was no correlationship in the two groups for all the phases between energy loss and vertical area or intensity.For each phases,vortical area of the control group was correlated with vortical intensity（r =0.396-0.809,P =0.003-0.000）.Only isovolumic vortical area was correlated with the vortex intensity in pacemaker group （r =0.807,P =0.000）.Conclusions The dual-chamber pacing of right ventricle and right atrium could induce a significant energy loss of left intra-ventricular fluid and obvious abnormal distribution of eddies during diastole.The disappearence of correlationship between vertical area and intensity in cardiac pacemaker group during left diastole might lead to more turbulance flow and energy loss of left ventricle during right dual chamber pacing.