Related Experiment Video

Updated: Mar 15, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
12:45

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

11.1K

Outcomes With Left Bundle Branch Block and Mildly to Moderately Reduced Left Ventricular Function

Chance M Witt1, Gang Wu1, Dachun Yang1

  • 1Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.

JACC. Heart Failure
|September 12, 2016
PubMed

Insights

Patients with left bundle branch block (LBBB) and mildly reduced ejection fraction have worse outcomes. LBBB is a negative prognostic marker in this group, indicating potential benefit from cardiac resynchronization therapy.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Heart Failure Management

Background:

  • Left bundle branch block (LBBB) is linked to adverse outcomes in severe heart failure.
  • Prognosis of LBBB in mildly to moderately reduced ejection fraction (36-50%) is not well-defined.
  • Understanding LBBB's impact in this group is crucial for cardiac resynchronization therapy (CRT) decisions.

Purpose of the Study:

  • To define the prognosis of patients with LBBB and mildly to moderately reduced left ventricular ejection fraction (LVEF).
  • To determine if LBBB remains a negative prognostic marker in this specific patient cohort.
  • To inform potential CRT benefits for patients with LBBB and LVEF between 36-50%.

Main Methods:

  • Retrospective analysis of patients with LBBB and LVEF 36-50% (1994-2014).
  • Inclusion criteria: LBBB, baseline echocardiogram, LVEF 36-50%.
  • Matched control group without conduction abnormalities compared for outcomes.

Main Results:

  • LBBB associated with significantly higher mortality (HR 1.17).
  • Increased risk of LVEF drop to ≤35% (HR 1.34) and need for ICD (HR 1.50).
  • Mortality remained significant after adjusting for comorbidities (p=0.04).

Conclusions:

  • Patients with LBBB and mildly to moderately reduced LVEF experience significantly worse clinical outcomes.
  • LBBB is a negative prognostic marker in this population.
  • This group warrants further investigation in prospective trials for CRT efficacy.
Abstract

Keywords:
cardiac resynchronization therapycardiomyopathyleft bundle branch blockleft ventricular systolic functionoutcomes

More Related Videos

Lumped-Parameter and Finite Element Modeling of Heart Failure with Preserved Ejection Fraction09:20

Lumped-Parameter and Finite Element Modeling of Heart Failure with Preserved Ejection Fraction

Published on: February 13, 2021

7.1K
Evaluation of Left Ventricular Structure and Function using 3D Echocardiography06:34

Evaluation of Left Ventricular Structure and Function using 3D Echocardiography

Published on: October 28, 2020

4.8K

Related Concept Videos

Mitral Stenosis I: Introduction01:22

Mitral Stenosis I: Introduction

Mitral Valve Stenosis (MVS) is a heart condition where the mitral valve narrows, impeding blood circulation from the left atrium to the left ventricle. The etiology and pathophysiology of this condition are multifaceted, leading to a cascade of cardiovascular complications.Causes of Mitral Valve StenosisRheumatic Heart Disease: It is the main cause of mitral valve stenosis, particularly in developing nations. This condition arises from rheumatic fever, an inflammatory illness resulting from...
1.1K
Heart Failure IV: Classification and Diagnostic Evaluation01:30

Heart Failure IV: Classification and Diagnostic Evaluation

Heart failure can be classified in various ways, with the most common classifications based on physical activity limitations, disease progression, severity, and treatment strategies.The Functional Classification of Heart Failure divides patients into four categories based on physical activity limitation due to symptom burden.Class I: Patients in this class have cardiac disease but no physical activity limitations. Ordinary activities like walking, climbing stairs, or routine tasks do not cause...
520
Mitral Regurgitation I: Introduction01:20

Mitral Regurgitation I: Introduction

Mitral regurgitation is characterized by the backward circulation of blood from the left ventricle to the left atrium during systole, a phase of the cardiac cycle when the heart contracts and pumps blood out of the chambers. This abnormal flow occurs primarily due to the dysfunction of the mitral valve or its supporting structures, which include the mitral leaflets, chordae tendineae, annulus, and papillary muscles.Etiology and Mechanisms:Primary Mitral Regurgitation: This type arises from...
838
Pathophysiology of Heart Failure01:17

Pathophysiology of Heart Failure

Heart failure (HF) is a progressive syndrome involving ventricles that leads to inadequate cardiac output. It can be classified based on location and output or ejection fraction. Ejection fraction (EF) is an essential measurement in the diagnosis and surveillance of HF. Reduced EF corresponds to systolic heart failure (HFrEF). However, HF with preserved ejection fraction (HFpEF) is becoming increasingly prevalent. Also known as diastolic HF, this form of HF is related to aging. The...
4.4K
Mitral Stenosis II: Clinical features and Diagnostic Tests01:23

Mitral Stenosis II: Clinical features and Diagnostic Tests

Mitral stenosis is a heart condition in which the mitral valve, which allows blood to flow from the left atrium to the left ventricle, becomes narrowed or stenotic. This narrowing hinders blood flow and leads to clinical symptoms requiring specific medical evaluations and management strategies. The following overview outlines the clinical symptoms, assessments, diagnostic findings, prevention methods, and treatments for mitral stenosis.Clinical ManifestationsDyspnea (shortness of breath): This...
384
Cardiomyopathy III: Hypertrophic Cardiomyopathy01:29

Cardiomyopathy III: Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the...
611