医学
左束支阻滞
QRS波群
心脏病学
内科学
束支阻滞
心向量图
接收机工作特性
心电图
心前检查
心力衰竭
作者
Alexei Shvilkin,Boško Bojović,Branislav Vajdić,Ihor Gussak,Kalon K.L. Ho,Peter Zimetbaum,Mark E. Josephson
出处
期刊:Heart Rhythm
[Elsevier]
日期:2010-08-01
卷期号:7 (8): 1085-1092
被引量:22
标识
DOI:10.1016/j.hrthm.2010.05.024
摘要
Background There are no established criteria to differentiate new from old left bundle branch block (LBBB). This complicates management of patients with LBBB and suspected acute coronary syndrome. Objectives The purpose of this study was to develop electrocardiographic (ECG) criteria to differentiate new and old LBBB. Methods All LBBB tracings (n = 3,706) in a hospital ECG database were retrieved. New (<24 hours, n = 39) and old (>24 hours, n = 1,760) LBBB tracings were identified. QRS and T-wave amplitudes, directions, and durations were measured digitally. Vectorcardiograms were reconstructed from 12-lead ECGs using inverse Dower transform and analyzed with Cardio3KG software. Receiver operator characteristic (ROC) curves were used to develop decision rules to distinguish new and old LBBB. Results The new LBBB group had larger T-vector magnitude (1.20 ± 0.07 vs. 0.71 ± 0.01 mV), smaller QRS vector magnitude (2.13 ± 0.12 vs. 2.47 ± 0.02 mV), and a lower QRS/T vector magnitude ratio (QRS/T; 1.79 ± 0.03 vs. 3.92 ± 0.04) compared with the old LBBB group (mean ± standard error of the mean, P <.001). The ratio of deepest S to largest T wave in precordial leads (Max S/T) was significantly smaller in the new compared with in the old LBBB group (1.66 ± 0.05 vs. 3.54 ± 0.08; P <.001). A decision rule using QRS/T <2.25 and Max S/T <2.5 had 100% sensitivity and 96%–68% specificity in diagnosing new LBBB, including subsets of patients with tachycardia and ischemia. Conclusions QRS/T and Max S/T allow accurate discrimination between new and old LBBB suitable for both computerized and manual analysis. If confirmed in prospective studies, this finding can improve management of patients with chest pain and LBBB. There are no established criteria to differentiate new from old left bundle branch block (LBBB). This complicates management of patients with LBBB and suspected acute coronary syndrome. The purpose of this study was to develop electrocardiographic (ECG) criteria to differentiate new and old LBBB. All LBBB tracings (n = 3,706) in a hospital ECG database were retrieved. New (<24 hours, n = 39) and old (>24 hours, n = 1,760) LBBB tracings were identified. QRS and T-wave amplitudes, directions, and durations were measured digitally. Vectorcardiograms were reconstructed from 12-lead ECGs using inverse Dower transform and analyzed with Cardio3KG software. Receiver operator characteristic (ROC) curves were used to develop decision rules to distinguish new and old LBBB. The new LBBB group had larger T-vector magnitude (1.20 ± 0.07 vs. 0.71 ± 0.01 mV), smaller QRS vector magnitude (2.13 ± 0.12 vs. 2.47 ± 0.02 mV), and a lower QRS/T vector magnitude ratio (QRS/T; 1.79 ± 0.03 vs. 3.92 ± 0.04) compared with the old LBBB group (mean ± standard error of the mean, P <.001). The ratio of deepest S to largest T wave in precordial leads (Max S/T) was significantly smaller in the new compared with in the old LBBB group (1.66 ± 0.05 vs. 3.54 ± 0.08; P <.001). A decision rule using QRS/T <2.25 and Max S/T <2.5 had 100% sensitivity and 96%–68% specificity in diagnosing new LBBB, including subsets of patients with tachycardia and ischemia. QRS/T and Max S/T allow accurate discrimination between new and old LBBB suitable for both computerized and manual analysis. If confirmed in prospective studies, this finding can improve management of patients with chest pain and LBBB.
科研通智能强力驱动
Strongly Powered by AbleSci AI