希浦系统起搏生理性心脏同步化治疗

His Purkinje Conduction System Pacing cardiac synchronization therapy

传统心脏再同步化治疗(CRT)即双心室起搏(BVP)通过经冠状静脉窦(CS)心外膜单点或多位点起搏,利用各种算法达到起搏与自身融合,实现部分宽QRS患者心脏电与机械再同步,改善临床预后;但对于自身窄QRS波,则无法保持其同步性。目前已开展的希浦系统起搏(HPCSP)主要包括希氏束起搏(HBP)和左束支起搏(LBBP)最具生理性。对自身窄QRS波患者,HBP可维持心室电和机械同步性;对典型左束支传导阻滞(LBBB),HBP可纠正其传导,恢复心室电和机械同步性,但多数患者起搏电极无法真正跨越阻滞位点,起搏阈值高及不稳定,存在安全隐患,成功率较低。近年来LBBP技术通过直接夺获左束支,维持或恢复左心室内同步性。因近端左束支传导系统是宽的网状结构,且起搏导线电极位于左心室间隔内膜下,往往可跨越传导阻滞位点,故左束支夺获阈值低且稳定,感知良好,并均伴有较好左心室同步性的左心室间隔起搏作为备份起搏。HPCSP也可通过与自身传导束融合,在单点HPCSP无法达到心脏完全同步化(如调整AV间期,消除左束支起搏的右束支阻滞图形),或双心室无法实现自身融合等患者(心房颤动,长PR间期和房室传导阻滞)中实现更好的心脏同步化。期待在植入技术的完善、专用器械改进及更多的循证医学之后,HPCSP在生理性心脏同步化治疗中得到广泛应用。

The traditional cardiac resynchronization therapy(CRT),also called biventricular pacing(BVP),is implemented by epicardium single or multi-site pacing through the coronary sinus(CS)with utilizing algorithms to get fused with native conduction which achieves cardiac electrical and mechanical synchronization in partial patients with wide QRS.But BVP cannot maintain cardiac synchronization in patients with native narrow QRS.The his purkinje conduction System Pacing(HPCSP)including his bundle pacing(HBP)and left bundle branch pacing(LBBP),has been demonstrated as the most physiological ventricular pacing.For patients with narrow QRS,HBP keeps ventricular electrical and mechanical synchrony.For patients with typical LBBB,HBP normalizes the bundle branch block and restores ventricular electrical and mechanical synchronization.However,the HBP pacing lead cannot truly pass the block site,leading to high and unstable threshold with potential safety,and therefore the success rate of implantation is relatively low.In recent years,the LBBP technology could reserve or preserve the left ventricular(LV)synchrony by directly capturing the left bundle branch.Because the proximal left bundle branch conduction system is a wide reticular structure,and the LBBP lead is located under the left ventricular septal endometrium,which could easily pass the conduction block site.LBBP has the low and stable threshold and R wave amplitude which also has LV septal pacing with good LV synchrony as backup pacing.HPCSP can also be fused with the native conduction bundle when single-site his-purkinje system pacing is incapable of achieving complete cardiac synchronization(such as adjusting the AV interval to eliminate the right bundle branch block pattern induced by LBBP)or better cardiac synchronization in patients who cannot achieve native fusion without adjustable AV interval(such as long P-R interval,atrial fibrillation and complete atrioventricular block).With the development of implantation technology and specialized tools as well as more and more evidence-based data,we are looking forward to the widespread application of HPCSP as the physiological cardiac synchronization therapy.