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Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
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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

In search of left septal fascicular block

Rex N MacAlpin1

  • 1Division of Cardiology, Department of Medicine, University of California at Los Angeles, Los Angeles, Calif, USA. rmacalpi@ucla.edu

American Heart Journal
|December 18, 2002
PubMed

Insights

The existence of left septal fascicle block, a controversial electrocardiographic finding, is supported by new diagnostic criteria. This condition, found in 0.5% of ECGs, may explain unclear electrocardiogram abnormalities.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Diagnostics

Background:

  • The left bundle branch in humans typically trifurcates into anterior, posterior, and septal fascicles.
  • Conduction abnormalities in the anterior and posterior fascicles are well-established.
  • Diagnosis of left septal fascicle block remains controversial due to a lack of consensus criteria.

Purpose of the Study:

  • To investigate the existence of left septal fascicle block.
  • To establish diagnostic criteria for left septal fascicle block.
  • To explore the clinical significance of this condition.

Main Methods:

  • A retrospective review of approximately 26,000 electrocardiograms (ECGs).
  • Application of newly derived criteria for left septal fascicle block.
  • Selection and analysis of illustrative ECG examples.

Main Results:

  • Electrocardiograms consistent with left septal fascicle block were identified in approximately 0.5% of the reviewed tracings.
  • The study presents illustrative ECG examples supporting the proposed diagnostic criteria.
  • Reasons for the selection of these specific ECGs are discussed.

Conclusions:

  • The findings suggest that left septal fascicle block is a real electrocardiographic entity.
  • Left septal fascicle block exhibits polymorphic patterns.
  • This condition may account for previously unexplained electrocardiographic abnormalities.
Abstract

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