Related Experiment Video

Updated: May 6, 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

10.2K

Electrocardiographic predictors of response to cardiac resynchronization therapy in patients with intraventricular

Yoichi Takaya1, Takashi Noda, Ikutaro Nakajima

  • 1Divisions of Arrhythmia and Electrophysiology, National Cerebral and Cardiovascular Center.

Circulation Journal : Official Journal of the Japanese Circulation Society
|October 29, 2013
PubMed

Insights

Predicting cardiac resynchronization therapy (CRT) response in patients with intraventricular conduction delay (IVCD) is crucial. Left axis deviation at baseline and ECG changes after CRT, like QRS duration shortening, predict successful CRT outcomes.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Diagnostics

Background:

  • Predictors of cardiac resynchronization therapy (CRT) response in patients with intraventricular conduction delay (IVCD) remain poorly understood.
  • Identifying reliable indicators for CRT success in this specific patient group is essential for optimizing treatment.

Purpose of the Study:

  • To investigate the benefits of CRT in patients with IVCD.
  • To identify significant surface electrocardiogram (ECG) variables that predict response to CRT in patients with IVCD.

Main Methods:

  • Retrospective analysis of 152 CRT patients, focusing on 40 with IVCD.
  • Comparison of baseline ECG parameters (QRS duration, axis deviation) between responders and non-responders.
  • Evaluation of post-CRT ECG changes (ΔQRS, axis shift) and their correlation with response.

Main Results:

  • 40% of IVCD patients responded to CRT.
  • Responders exhibited wider baseline QRS duration and higher frequency of left axis deviation (LADEV).
  • Post-CRT, responders showed greater QRS shortening (ΔQRS) and axis shift from LADEV to right axis deviation (RADEV).

Conclusions:

  • Left axis deviation at baseline is a significant predictor of CRT response in IVCD patients.
  • Reversal of ventricular activation patterns on surface ECG after CRT, indicated by axis shift and QRS shortening, are important predictors of response.
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

2.4K
Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System06:40

Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System

Published on: May 22, 2018

10.6K

Related Concept Videos

Cardiomyopathy II: Dilated Cardiomyopathy01:30

Cardiomyopathy II: Dilated Cardiomyopathy

Dilated cardiomyopathy, or DCM, is a progressive myocardial disorder characterized by ventricular chamber dilation and contractile dysfunction.EtiologyVarious factors can cause DCM, including hypertension and heavy alcohol intake, which contribute to the weakening and enlargement of the heart muscle. Viral infections, such as Coxsackievirus B, adenoviruses, and influenza, can lead to DCM by causing inflammation and damage to heart tissue. Certain chemotherapeutic agents, including daunorubicin,...
802
Dysrhythmias V: Evaluating Dysrhythmias01:30

Dysrhythmias V: Evaluating Dysrhythmias

Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart...
428
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...
1.4K
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...
10.0K
Electrophysiology of Normal Cardiac Rhythm01:19

Electrophysiology of Normal Cardiac Rhythm

The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase...
7.8K
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias01:25

ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias

Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an...
1.2K