单心动周期全容积成像对右心室流出道起源室性期前收缩患者左心室容积及收缩同步性的研究

Study of left ventricular systolic volume and synchrony in patients with premature ventricular complexes from the right ventricular outflow tract by instantaneous full-volume imaging

目的探讨正常人及频发右室流出道（right ventricular outflowtract，RVOT）起源室性期前收缩患者左室容积改变模式。方法应用单心动周期全容积成像（instantaneous full—volume imaging，IFI）技术分析29例RVOT起源室性期前收缩患者在室性期前收缩、窦性心搏时以及30例正常人左室容积参数[收缩末容积（ESV）、舒张末容积（EDV）、每搏量（SV）、射血分数（EF）]和左室收缩期节段容积变化同步性参数[收缩失同步性指数（SDI）、收缩末离散度（DISPES）、平均收缩末时间（MES）、收缩前时间容积（PreContr）、收缩后时间容积（PostContr）]。进行左室容积收缩波序标测。结果与正常对照组比较，RVOT起源室性期前收缩患者在室性期前收缩时左室容积参数EDV、SV、EF均显著降低（P〈0．01）；左室收缩期节段容积变化同步性参数均显著增高（P〈0．01）。室性期前收缩患者在窦性心搏时各项容积参数与正常对照组比较差异无统计学意义，而同步性参数中MES、PreContr与正常对照组比较差异有统计学意义（P〈0．01）。结论室性期前收缩时左室收缩期整体容积及节段容积的改变存在失同步状态，而在窦性心搏时也可能存在心肌收缩模式的改变。IFI技术可用于定量分析室性期前收缩患者左室容积的变化。

Objective To assess alternations in left ventricular volume and systolic synchrony in patients with frequent premature ventrieular complexes（PVCs） from the right ventricular outflow tract （RVOT）. Methods Twenty-nine patients with frequent isolated PVCs from RVOT were included and 30 healthy subjects as control. Instantaneous full-volume imaging（IFI） was performed to evaluate left ventricle volumetric parameters, including end-systolic volume （ESV）, end-diastolic volume （EDV）, stroke volume （SV）, ejection fraction （EF）, and systolic synchrony parameters, including systolic dyssynchrony index （SDI）, dispersion end-systole （DISPES）, mean end-systolic time （MES）, pre-contraction time volume （PreContr） and post-contraction time volume （PostContr）. Contraction front mapping was performed to visualize volumetric contraction sequence. All values of patients with PVCs were recorded during sinus beats （PVC-S） and premature ventricular beats （PVC-V） respectively. Results Significant differences were observed in left ventricular systolic volumetric and synchrony parameters between PVC-V and control subjects （ P 〈0.01）,as well as in MES and PreContr between PVC-S and control subjects （ P 〈0.01）. Conclusions Left ventricular systolic dysynchrony was demonstrated in patients with PVCs from RVOT. IFI was a novel tool to analyze left ventricular global and regional volumetric alternations.