通过斑点追踪应变观察急性左束支传导阻滞的即刻机械效应。

Immediate mechanical effects of acute left bundle branch block by speckle tracked strain.

作者信息

Klein Michael R, Sundh Frida, Simlund Jacob, Harrison J Kevin, Jackson Kevin P, Hughes G Chad, Wagner Galen S, Risum Niels, Søgaard Peter, Strauss David G, Kisslo Joseph

机构信息

Division of Cardiology, Duke University School of Medicine, Durham, NC, USA.

Division of Cardiology, Duke University School of Medicine, Durham, NC, USA; Department of Clinical Physiology, Karolinska Institute and Karolinska University Hospital, Stockholm, Sweden.

出版信息

J Electrocardiol. 2015 Jul-Aug;48(4):643-51. doi: 10.1016/j.jelectrocard.2015.05.005. Epub 2015 May 8.

DOI:10.1016/j.jelectrocard.2015.05.005

PMID:26002227

Abstract

INTRODUCTION

Left bundle branch block (LBBB) is a known complication of transcatheter aortic valve replacement (TAVR) and has been shown to predict worsened outcomes in TAVR patients. A regional longitudinal strain pattern, termed the "classic" pattern of left ventricular (LV) dyssynchrony, which is thought to be due to LBBB, is highly predictive of response to cardiac resynchronization therapy. Whether LBBB causes this "classic" pattern is not known.

METHODS

We retrospectively studied patients undergoing TAVR who also underwent pre- and post-TAVR strain analysis to determine if the "classic" pattern arose in those who developed TAVR-induced true LBBB. After removing patients with baseline conduction abnormalities or insufficient studies 9 patients had sufficient data for analysis. Six patients developed LBBB after TAVR and 3 patients did not develop LBBB after TAVR. ECGs were analyzed for the new onset of LBBB after TAVR. Global longitudinal strain (GLS) and regional longitudinal strain patterns were analyzed for changes between pre- and immediately post-TAVR examinations.

RESULTS

Patients who did not develop LBBB showed no significant changes in their regional longitudinal strain pattern. Those patients who did develop LBBB showed significant increase in their difference of time-to-onset of contraction between the septal and lateral walls post-TAVR (22 ± 14 ms vs 111 ± 49 ms; p=0.003) and in their difference of time-to-peak contraction between the septal and lateral walls post-TAVR (63 ± 56 ms vs 133 ± 46 ms; p=0.002). Early lateral wall pre-stretch and delayed lateral wall peak contraction emerged in all patients with LBBB but early septal peak contraction meeting the established criteria was present in only one patient.

DISCUSSION

The onset of LBBB led to acute, measurable changes in the regional longitudinal strain pattern consisting of early lateral wall pre-stretch and delayed lateral wall peak contraction. These represent 2 of the 3 findings in the "classic" pattern of LV dyssynchrony. Early termination of septal wall contraction meeting established criteria was not routinely found. Time and/or other factors may be required to develop the full "classic" pattern.

摘要

引言

左束支传导阻滞（LBBB）是经导管主动脉瓣置换术（TAVR）已知的并发症，并且已被证明可预测TAVR患者预后恶化。一种区域纵向应变模式，称为左心室（LV）不同步的“经典”模式，被认为是由LBBB引起的，它高度预测心脏再同步治疗的反应。LBBB是否导致这种“经典”模式尚不清楚。

方法

我们回顾性研究了接受TAVR且在TAVR前后均进行应变分析的患者，以确定“经典”模式是否出现在发生TAVR诱导的真正LBBB的患者中。在排除有基线传导异常或研究不充分的患者后，9例患者有足够的数据进行分析。6例患者在TAVR后发生LBBB，3例患者在TAVR后未发生LBBB。分析心电图以确定TAVR后新发LBBB情况。分析TAVR前和TAVR后即刻检查之间整体纵向应变（GLS）和区域纵向应变模式的变化。

结果

未发生LBBB的患者区域纵向应变模式无显著变化。发生LBBB的患者在TAVR后室间隔与侧壁之间收缩起始时间差显著增加（22±14毫秒对111±49毫秒；p = 0.003），以及TAVR后室间隔与侧壁之间收缩峰值时间差显著增加（63±56毫秒对133±46毫秒；p = 0.002）。所有发生LBBB的患者均出现早期侧壁预拉伸和延迟的侧壁峰值收缩，但只有1例患者出现符合既定标准的早期室间隔峰值收缩。