Ozpak Emine, Demolder Anthony, Kizilkilic Sevda, Calle Simon, Timmermans Frank, De Pooter Jan
Heart Center, Ghent University Hospital, Ghent, Belgium.
Front Cardiovasc Med. 2022 Jun 9;9:885201. doi: 10.3389/fcvm.2022.885201. eCollection 2022.
Left bundle branch area pacing (LBBAP) induces delayed RV activation and is thought to be harmless, since the electrocardiographic signature is reminiscent to native RBBB. However, to what extent the delayed RV activation during LBBAP truly resembles that of native RBBB remains unexplored.
This study included patients with incomplete RBBB (iRBBB), complete RBBB (cRBBB) and patients who underwent LBBAP. Global and right ventricular activation times were estimated by QRS duration and R wave peak time in lead V1 (V1RWPT) respectively. Delayed RV activation was further characterized by duration, amplitude and area of the terminal R wave in V1.
In patients with LBBAP ( = 86), QRS duration [120 ms (116, 132)] was longer compared to iRBBB patients ( = 422): 104 ms (98, 110), < 0.001, but shorter compared to cRBBB ( = 223): 138 ms (130, 152), < 0.001. V1RWPT during LBBAP [84 ms (72, 92)] was longer compared to iRBBB [74 ms (68, 80), < 0.001], but shorter than cRBBB [96 ms (86, 108), < 0.001]. LBBAP resulted in V1 R' durations [42 ms (28, 55)] comparable to iRBBB [42 ms (35, 49), = 0.49] but shorter than in cRBBB [81 ms (68, 91), < 0.001]. During LBBAP, the amplitude and area of the V1 R' wave were more comparable with iRBBB than cRBBB. V1RWPT during LBBAP was determined by baseline conduction disease, but not by LBBAP capture type.
LBBAP-induced delayed RV activation electrocardiographically most closely mirrors the delayed RV activation as seen with incomplete rather than complete RBBB.
左束支区域起搏（LBBAP）会导致右心室激活延迟，并且被认为是无害的，因为其心电图特征与生理性右束支传导阻滞相似。然而，LBBAP期间右心室激活延迟在何种程度上真正类似于生理性右束支传导阻滞仍未得到探索。
本研究纳入了不完全性右束支传导阻滞（iRBBB）、完全性右束支传导阻滞（cRBBB）患者以及接受LBBAP的患者。分别通过QRS波时限和V1导联R波峰时间（V1RWPT）来估算整体和右心室激活时间。右心室激活延迟通过V1导联终末R波的时限、振幅和面积进一步表征。
在接受LBBAP的患者（n = 86）中，QRS波时限[120 ms（116，132）]比不完全性右束支传导阻滞患者（n = 422）更长：104 ms（98，110），P < 0.001，但比完全性右束支传导阻滞患者（n = 223）更短：138 ms（130，152），P < 0.001。LBBAP期间的V1RWPT[84 ms（72，92）]比不完全性右束支传导阻滞更长[74 ms（68，80），P < 0.001]，但比完全性右束支传导阻滞更短[96 ms（86，108），P < 0.001]。LBBAP导致的V1导联R'波时限[42 ms（28，55）]与不完全性右束支传导阻滞相当[42 ms（35，49），P = 0.49]，但比完全性右束支传导阻滞更短[81 ms（68，91），P < 0.001]。在LBBAP期间，V1导联R'波的振幅和面积与不完全性右束支传导阻滞相比，比与完全性右束支传导阻滞更具可比性。LBBAP期间的V1RWPT由基线传导疾病决定，但不由LBBAP夺获类型决定。
LBBAP引起的右心室激活延迟在心电图上最接近不完全性而非完全性右束支传导阻滞时所见的右心室激活延迟。
