非选择性His束起搏下美敦力起搏器心室阈值管理功能的特殊心电图表现

The novel ECG phenomenon in non-selective His bundle pacing when running ventricular capture management function of Medtronic pacemaker

目的非选择性His束起搏(NS-HBP)患者,窦性心律下心室阈值管理功能(VCM)运作时,可产生宽QRS波及双脉冲现象,易被误诊为室性早搏(简称室早)及该室早触发的心室安全起搏(VSP)。现对这一特殊心电图现象进行解释说明,并提出鉴别方法。方法通过掌握His束起搏(HBP)的分类及特点、VCM运作方式、VSP触发条件,并结合三位患者的心电图资料,阐明该现象,找出鉴别方法。结果NS-HBP下VCM运作时,随着测试脉冲降低输出,His束失夺获,测试脉冲仅夺获临近心肌,产生宽QRS波,110ms后备用脉冲发放,形成了宽QRS波及间距110ms的双脉冲现象。VCM产生的宽QRS波及双脉冲有特征性"3+1"现象,即每三跳窄QRS波后,规律出现一次宽QRS波及双脉冲,而室早触发的VSP无特定规律;VCM运作时,宽QRS波中的双脉冲分别为心室测试和备用脉冲,室早触发VSP的双脉冲依次为心房和心室起搏脉冲;窦性心律下VCM产生宽QRS波时,SAV固定缩短110ms;HBP位点靠近右室间隔上部区域,当测试脉冲仅夺获临近心肌时,宽QRS波形态类似右室间隔部起搏图形,而室早的形态多变。结论NS-HBP患者,窦性心律下VCM产生的宽QRS波及双脉冲现象易与室早触发的VSP相混淆,通过"3+1"的表现形式、双脉冲性质的判断、AV间期的改变、宽QRS波的形态可对两者予以鉴别。

Objective We found wide QRS complex and double pacing pulses in non-selective His bundle pacing(NS-HBP)patients when running ventricular capture management(VCM)function,which can be misdiagnosed as premature ventricular contraction(PVC)and ventricular safety pacing(VSP).We aim to clarify this novel ECG phenomenon and find ways to distinguish them.Methods Through learning categories and features of His bundle pacing(HBP),operation mode of VCM,trigger conditions of VSP and combining three patients ECG data to explain and distinguish this phenomenon.Results During VCM,as test pulse decreasing output,only adjacent myocardium being captured while His bundle lost capture,forming wide QRS complex and after 110 ms a backup pulse release,which causing a wide QRS complex and double pulses with 110 ms interval in NS-HBP.Wide QRS and double pulses caused by VCM had the feature of 3+1,they usually appeared after three narrow QRS complexes,while PVC and VSP were random.Double pulses were ventricular test pulse and backup pulse in VCM,however,they were atrial pulse and ventricular pulse in VSP.When running VCM under sinus rhythm,sensed atrioventricular interval(AV)will decreased 110 ms.As HBP site closed to upper area of right ventricular septum,if test pulse only captured adjacent myocardium,the morphology of wide QRS was similar to pacing in right ventricular septum,but PVC morphology was changeable.Conclusion In NS-HBP patients,wide QRS and double pulses caused by VCM under sinus rhythm can be misdiagnosed as PVC and VSP,we can distinguish them by means of manifestation of 3+1,nature of double pulses,changes of AV interval and morphology of wide QRS complex.[Chinese Journal of Cardiac Pacing and Electrophysiology,2020,34(2):109-115]