心电图导联 ST 段抬高时 QRS 时限和 R 波振幅的变化可区分心外膜和透壁性心肌损伤。

Changes in QRS duration and R-wave amplitude in electrocardiogram leads with ST segment elevation differentiate epicardial and transmural myocardial injury.

机构信息

Department of Cardiology, Institute of Biomedical Research (IIB Sant Pau), Autonomous University of Barcelona, Barcelona, Spain.

出版信息

Heart Rhythm. 2010 Nov;7(11):1667-73. doi: 10.1016/j.hrthm.2010.07.010. Epub 2010 Jul 13.

DOI:10.1016/j.hrthm.2010.07.010

PMID:20633701

Abstract

BACKGROUND

Acute transmural ischemia increases QRS duration and R-wave amplitude owing to depressed intramyocardial activation. Theoretically, when myocardial injury is confined to the epicardium, the intramyocardial activation is preserved without affecting QRS duration.

OBJECTIVE

The purpose of this study was to distinguish epicardial from transmural myocardial injury based on the analysis of the QRS complex in leads with ST segment elevation.

METHODS

Electrophysiological effects of epicardial injury induced by topical application (n = 7) or intrapericardial injection (n = 10) of potassium were assessed in pigs in local electrograms recorded with needles in the left ventricle and in the peripheral 12-lead electrocardiogram (ECG), respectively, and were compared with transmural injury induced by acute left anterior descending (LAD) occlusion in the same pig.

RESULTS

Epicardial application of 50 mM potassium induced ST segment elevation in epicardial (0.2 ± 0.06 to 0.5 ± 0.09 mV; P <.05) but not in midmyocardial local electrograms (0.1 ± 0.07 to -0.1 ± 0.09 mV). Local midmyocardial activation times were not affected by epicardial applied potassium (182 ± 5.9 vs. 183 ± 5.8 ms) but increased significantly during acute LAD occlusion (246 ± 20.9 ms; P <.01). Intrapericardial injected potassium induced ST segment elevation on average in nine of 12 ECG leads but did not change QRS duration and R-wave amplitude. Acute LAD occlusion induced ST segment elevation (five of 12 leads) associated with increased QRS duration (69 ± 1.2 to 89 ± 3.6 ms; P <.001) and R-wave amplitude (0.1 ± 0.01 to 0.7 ± 0.09 mV; P <.001) in the ECG.

CONCLUSION

Transmural but not epicardial myocardial injury delays intramural local activation and is associated with QRS prolongation and enlarged R-wave amplitude in leads with ST segment elevation. This differential ECG pattern may help to distinguish acute pericarditis (epicardial injury) from acute transmural ischemia in clinical practice.

摘要

背景

急性透壁性缺血会导致心肌内激活受到抑制，从而增加 QRS 持续时间和 R 波振幅。理论上，当心肌损伤仅限于心外膜时，心肌内激活得以保留，而不会影响 QRS 持续时间。

目的

本研究旨在根据 ST 段抬高导联中 QRS 复合波的分析，区分心外膜和透壁性心肌损伤。

方法

通过在左心室和外周 12 导联心电图（ECG）记录的针状局部电图中分别评估心外膜局部应用（n = 7）或心包内注射（n = 10）钾引起的电生理效应，并将其与同一头猪中急性左前降支（LAD）闭塞引起的透壁性损伤进行比较。

结果

50mM 钾心外膜应用引起心外膜（0.2±0.06 至 0.5±0.09mV；P<.05）而非心外膜局部电图（0.1±0.07 至-0.1±0.09mV）ST 段抬高。心外膜局部钾应用不影响局部心中层激活时间（182±5.9 与 183±5.8ms），但在急性 LAD 闭塞时显著增加（246±20.9ms；P<.01）。心包内注射钾平均引起 12 导联 ECG 中的 9 个导联 ST 段抬高，但不改变 QRS 持续时间和 R 波振幅。急性 LAD 闭塞引起 ST 段抬高（12 导联中的 5 个导联），伴有 QRS 持续时间（69±1.2 至 89±3.6ms；P<.001）和 R 波振幅（0.1±0.01 至 0.7±0.09mV；P<.001）在 ECG 中的增加。