Increases in repolarization heterogeneity predict left ventricular systolic dysfunction and response to cardiac
Hui-Chun Huang1, Kuo-Liong Chien1,2, Yi-Chung Chang3
1Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Insights
T-wave morphology changes in complete left bundle branch block (cLBBB) correlate with reduced left ventricular ejection fraction (LVEF). Specific T-wave measures predict response to cardiac resynchronization therapy (CRT).
Area of Science:
- Cardiology
- Electrophysiology
- Medical Imaging
Background:
- Complete left bundle branch block (cLBBB) often presents with impaired left ventricular ejection fraction (LVEF).
- T-wave morphology analysis offers insights into cardiac repolarization abnormalities.
- Predicting response to cardiac resynchronization therapy (CRT) is crucial for patient management.
Purpose of the Study:
- To investigate the association between T-wave morphology and impaired LVEF in cLBBB patients.
- To evaluate the predictive value of T-wave morphology for CRT response.
- To identify novel electrocardiographic markers for CRT patient selection.
Main Methods:
- 189 cLBBB patients underwent ECG and echocardiography.
- T-wave morphology parameters (TCRT, TMD, PL, TWR) were analyzed from ECGs.
- CRT response defined by LVEF improvement; clinical outcomes tracked over 5.8 years.
Main Results:
- Increased T-wave morphology dispersion (TMD) and T-wave residuum (TWR) were associated with LVEF < 40%.
- In CRT patients, larger TMD, PL, and more negative TCRT predicted better response.
- Large TMD and PL independently predicted favorable clinical outcomes post-CRT.
Conclusions:
- Repolarization heterogeneity, indicated by T-wave morphology, is linked to impaired LVEF in cLBBB.
- TMD and PL show promise as additional predictors for CRT response.
- These findings may enhance patient selection for CRT, optimizing treatment efficacy.
Introduction:
This study aimed to investigate the association between T-wave morphology and impaired left ventricular ejection fraction (LVEF) in patients with complete left bundle branch block (cLBBB), and the predictive value of T-wave morphology for response to cardiac resynchronization therapy (CRT).
Methods And Results:
We enrolled 189 patients with cLBBB on electrocardiogram performed between January 2007 and December 2011 who underwent standard echocardiography. Repolarization parameters, including the QRS-to-T angle (TCRT), T-wave morphology dispersion (TMD), T-wave loop area (PL), and T-wave residuum (TWR), were reconstructed from digital standard 12-lead electrocardiograms by T-wave morphology analysis. CRT response was defined as ≥15% reduction in left ventricular end-systolic volume at 12 months after CRT implantation. The clinical outcome endpoint was a composite of heart failure hospitalization, heart transplantation, or death during follow up (mean, 5.8 years). On logistic regression, a higher heart rate, longer QRS duration, increased TMD, and larger TWR were all independently associated with LVEF < 40%. Among 40 patients who underwent CRT, those with a larger TMD (P = .007), larger PL (P = .025), and more negative TCRT (P = .015) had better response to CRT. A large TMD (P = .018) and large PL (P = .003) were also independent predictors of the clinical outcome endpoint.
Conclusions:
Increases in repolarization heterogeneity in patients with cLBBB are associated with impaired LVEF. A large TMD and large PL may be useful as additional predictors of response to CRT, improving patient selection for CRT.
Related Concept Videos
01:20Mitral Regurgitation I: Introduction
01:18Dysrhythmias IV: Characteristics of Bradyarrhythmias
01:22Mitral Stenosis I: Introduction
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
01:29Heart Failure II: Pathophysiology
01:29Cardiomyopathy IV: Restrictive Cardiomyopathy