Related Experiment Video

Updated: Jun 22, 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

Surface electrocardiogram to predict outcome in candidates for cardiac resynchronization therapy: a sub-analysis of

Renaud Gervais1, Christophe Leclercq, Aparna Shankar

  • 1Département de Cardiologie, Centre Hospitalier Universitaire Pontchaillou, 35033 Rennes cedex 09, France.

European Journal of Heart Failure
|June 10, 2009
PubMed

Insights

Cardiac resynchronization therapy (CRT) improves outcomes in heart failure. Specific electrocardiographic measures like prolonged PR interval and right bundle branch block (BBB) at baseline predict poor outcomes, while QRS duration at 3 months is also a key predictor.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Heart Failure Management

Background:

  • Cardiac resynchronization therapy (CRT) is established for moderate to severe heart failure.
  • Predictors of long-term outcomes in CRT patients require further investigation.

Purpose of the Study:

  • To evaluate if baseline and follow-up electrocardiographic (ECG) characteristics predict long-term outcomes in heart failure patients treated with CRT.
  • To identify specific ECG parameters associated with morbidity and mortality post-CRT.

Main Methods:

  • Analysis of data from the CARE-HF trial, randomly assigning patients to medical therapy (MT) plus CRT or MT alone.
  • Electrocardiographic measurements taken at baseline and 3-month follow-up.
  • Outcome defined as freedom from death, urgent transplantation, or cardiovascular hospitalization.

Main Results:

  • Baseline prolonged PR interval, left QRS axis, and left bundle branch block (BBB) predicted unfavorable outcomes.
  • At 3 months, heart rate, PR interval, and QRS duration predicted unfavorable outcomes.
  • Multiple variable analysis identified treatment assignment, baseline PR, and right BBB as significant predictors; baseline JTc and 3-month QRS duration predicted mortality and hospitalization.

Conclusions:

  • Baseline QRS duration did not predict outcome, but 3-month QRS duration did.
  • Prolonged PR interval and right BBB were associated with particularly high event rates.
  • ECG characteristics provide valuable prognostic information in CRT patients.
Abstract

More Related Videos

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System10:17

Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

Published on: April 11, 2025

Related Concept Videos

Electrocardiogram01:29

Electrocardiogram

An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity.
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
Acute Coronary Syndrome III: Diagnostic Studies01:30

Acute Coronary Syndrome III: Diagnostic Studies

Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital...
Cardiopulmonary Resuscitation III: AED Use01:23

Cardiopulmonary Resuscitation III: AED Use

Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary...
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...
Pulse rhythm01:30

Pulse rhythm

Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding.
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...