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Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Left bundle branch block, an old-new entity.
Günter Breithardt1, Ole-Alexander Breithardt
1Department of Cardiology and Angiology, Hospital of the University of Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany. g.breithardt@uni-muenster.de
Journal of Cardiovascular Translational Research
|January 20, 2012
Summary
Left bundle branch block (LBBB) indicates a poorer prognosis and can signal underlying heart disease. It may cause left ventricular dysfunction, sometimes treatable with biventricular pacing.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiovascular Medicine
Background:
- Left bundle branch block (LBBB) is associated with worse outcomes than normal conduction or right bundle branch block.
- LBBB can be an early sign of diffuse myocardial disease.
- It presents with specific ECG criteria: prolonged QRS (>0.11s), delayed intrinsic deflection in V5/V6 (>60ms), and absent septal q waves.
Purpose of the Study:
- To explore the implications of LBBB on left ventricular function.
- To investigate the potential for latent cardiomyopathy in patients with LBBB and preserved ejection fraction.
- To understand the mechanisms linking LBBB to cardiac dysfunction and potential interventions.
Main Methods:
- Analysis of ECG criteria for LBBB.
- Assessment of left ventricular performance and contractility.
- Evaluation of myocardial response to exercise, pacing, and biopsy in specific patient groups.
Main Results:
- LBBB can lead to asynchronous ventricular contraction, causing abnormal hypertrophy and dilatation.
- Patients with LBBB and normal resting function may exhibit exercise-induced pulmonary hypertension or ischemia.
- Abnormal myocardial biopsy findings suggest underlying pathology in some LBBB cases.
Conclusions:
- LBBB significantly impacts cardiac prognosis and function.
- Asynchronous activation due to LBBB can induce or worsen left ventricular dysfunction.
- The concept of 'latent cardiomyopathy' is relevant for LBBB patients with preserved ejection fraction but abnormal stress responses.
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