左束支起搏心电图的特点观察

Characteristics of Electrocardiogram in Left Bundle Branch Pacing

目的通过比较自身心律、左束支起搏、右室心尖部或右室流出道起搏时心电图的形态和QRS波群时限等,找寻左束支起搏心电图的特征表现。方法选取拟行左束支起搏42例患者,记录标准12导联体表心电图,通过测量,分别比较自身心律、左束支起搏及右室心尖部/右室流出道起搏时QRS波群时限、电轴、形态及ST段的差异。结果自身心律与左束支起搏相比,QRS波群时限无统计学差异(P=0. 49),但与右室心尖部/右室流出道起搏相比,具有显著差异(P <0. 000)。左束支起搏组,V1导联呈特征性"M"或"r SR"的比例为76. 19%;a VR导联亦可呈特征性"M"或"r SR"表现,比例为78. 57%。对于自身心律为右束支阻滞者,左束支区域起搏仅V1导联呈"M"或"r SR",a VR导联呈QS型,而无特征性"M"或"r SR"表现。与经典的右束支阻滞心电图比较:左束支起搏ST段和T波改变无规律性。结论左束支起搏心电图QRS波群时限和电轴与自身心律相比无显著差别,V1及a VR导联均可见特征性"M"或"r SR"表现,右束支阻滞患者仅V1导联呈特征性表现,但依靠心电图的特征性"M"或"r SR"改变判断起搏位点有局限性。

Objective To confirm the characteristics of left bundle branch pacing( LBBP) electrocardiogram( ECG) by comparing the morphology and QRS duration of ECG during self rhythm,LBBP,right ventricular apex( RVA) or right ventricular outflow tract( RVOT)pacing. Methods 42 cases undergoing LBBP were selected and the standard 12 lead ECG was recorded. The differences of QRS duration,electrical axis,morphology and ST segment were compared in self rhythm,LBBP and RVA/RVOT pacing. Results There was no significant difference in QRS duration between LBBP and RVA/RVOT( P < 0. 000). In LBBP group,76. 19% of leads V1 showed the characteristic"M"or"r SR",and 78. 57% of leads a VR showed the characteristic"M"or"r SR". For the patients with right bundle branch block( RBBB),only lead V1 showed"M"or"r SR",lead a VR showed QS,but no characteristic"M"or"r SR". Compared with the classic ECG of RBBB,the ST segment and T wave changes of LBBP were not regular. Conclusion There are no significant differences in QRS duration and electrical axis between LBBP and self rhythm. The characteristic morphology,"M"or"r SR"can be seen in leads V1 and a VR,while only lead V1 shows the characteristic performance in patients with RBBB. It is limited to judge pacing sites by the characteristic"M"or"r SR"changes of ECG.