Alqarawi Wael, Sadek Mouhannad M, Golian Mehrdad, Hibbert Benjamin, Redpath Calum J, Nair Girish M, Nery Pablo B, Davis Darryl R, Klein Andres, Birnie David H, Green Martin S
Arrhythmia Service, Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Canada.
Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Canada.
J Electrocardiol. 2020 Nov-Dec;63:167-172. doi: 10.1016/j.jelectrocard.2019.10.005. Epub 2019 Oct 22.
Current LBBB definitions cannot always distinguish LBBB from left ventricular conduction delay. Only patients with LBBB are expected to normalize with His bundle pacing. Patients who develop new LBBB immediately post transcatheter aortic valve replacement (TAVR) provide an excellent model to define electrocardiogram (ECG) features of LBBB. We sought to describe their ECG features and develop a new ECG definition of LBBB.
We screened ECGs from 264 consecutive patients who underwent TAVR at the University of Ottawa Heart Institute. Patients with a baseline QRS of ≤100 ms who developed QRS ≥120 ms immediately after TAVR were included. Two electrocardiologists reviewed all ECG independently. Baseline demographics and echocardiographic data were retrospectively collected.
36 patients were included in the analysis. The median age was 85.5 years (IQR, 81.8-89 years) and 52.8% were males. The minimum QRS duration was 126 ms. The median QRS axis was -18° (IQR, -40-4.5°), which is 18.5° leftward compared to the median QRS axis before TAVR. Fourteen patients (38.9%) had left axis deviation. All patients had a notched/slurred R wave in at least one lateral lead and an R wave duration of ≤20 ms in V1 when present.
We developed a new ECG definition of LBBB that includes 2 novel findings: notching/slurring of the R wave in at least one lateral lead and an R wave ≤20 ms in V1. Further larger studies are warranted to confirm these findings.
目前的左束支传导阻滞（LBBB）定义并不总能将LBBB与左心室传导延迟区分开来。只有LBBB患者有望通过希氏束起搏实现正常化。经导管主动脉瓣置换术（TAVR）后立即出现新发LBBB的患者为定义LBBB的心电图（ECG）特征提供了一个极佳的模型。我们试图描述其ECG特征并制定LBBB的新ECG定义。
我们筛选了渥太华大学心脏研究所连续264例接受TAVR患者的ECG。纳入基线QRS时限≤100毫秒且TAVR后立即出现QRS≥120毫秒的患者。两名心电图专家独立审查所有ECG。回顾性收集基线人口统计学和超声心动图数据。
36例患者纳入分析。中位年龄为85.5岁（四分位间距，81.8 - 89岁），52.8%为男性。最小QRS时限为126毫秒。中位QRS电轴为 - 18°（四分位间距， - 40 - 4.5°），与TAVR前的中位QRS电轴相比向左偏移18.5°。14例患者（38.9%）有左轴偏移。所有患者至少在一个侧壁导联有切迹/顿挫的R波，且V1导联（若有）的R波时限≤20毫秒。
我们制定了LBBB的新ECG定义，包括两项新发现：至少一个侧壁导联R波有切迹/顿挫以及V1导联R波≤20毫秒。需要进一步开展更大规模的研究来证实这些发现。
