Related Experiment Video
Updated: Aug 18, 2026
Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Electrocardiogram in patients with fasciculoventricular pathways: a comparative study with anteroseptal and midseptal
Eduardo Back Sternick1, Luz-Maria Rodriguez, Luiz M Gerken
1Department of Arrhythmia and Electrophysiology, Biocor Instituto, Nova Lima, Brazil. eduardosternick@aol.com
Insights
Electrocardiogram (ECG) analysis reveals fasciculoventricular pathways share ECG features with septal accessory pathways, but typically present with a narrower QRS complex. Differentiating these pathways solely by ECG can be challenging.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Diagnostics
Background:
- Electrophysiology suggests fasciculoventricular pathways are septally located.
- Surface ECG during sinus rhythm may resemble anteroseptal and midseptal bypass tracts.
Purpose of the Study:
- Describe the ECG profile of fasciculoventricular pathways.
- Compare this profile to anteroseptal and midseptal accessory pathways.
Main Methods:
- Analysis of 12-lead ECGs from 7 patients with fasciculoventricular pathways and 40 patients with septal accessory pathways.
- Evaluation of QRS and delta wave axis, QRS width, R/S ratio, delta wave negativity, and R/S transition.
Main Results:
- Fasciculoventricular pathways exhibit a variable ECG pattern, sharing features with both anteroseptal and midseptal accessory pathways.
- Narrower QRS width is a key differentiator (P <.0001).
- Frontal plane axis differentiates from anteroseptal but not midseptal pathways.
Conclusions:
- Sinus rhythm ECGs of fasciculoventricular pathways resemble those of septal accessory pathways but usually have narrower QRS complexes.
- ECG during sinus rhythm cannot reliably distinguish broad QRS fasciculoventricular pathways from anteroseptal or midseptal bypass tracts.
Objectives:
The purpose of this study was to describe the ECG profile of a cohort of patients with fasciculoventricular pathways and compare the profile with the ECG of patients with anteroseptal and midseptal accessory pathways.
Background:
Electrophysiologic findings suggest fasciculoventricular pathways insert into the septal region. Findings also suggest the 12-lead surface ECG during sinus rhythm is similar to the ECG of patients with anteroseptal and midseptal bypass tracts.
Methods:
Four different observers analyzed the 12-lead ECG of seven patients with fasciculoventricular pathways (group I) and the ECG of 20 patients with midseptal AV accessory pathways (group II) and 20 patients with anteroseptal AV accessory pathways (group III). The following variables were analyzed: ECG frontal plane QRS and delta wave axis; angle between the QRS and the delta wave axis; QRS width; R/S ratio in lead III; presence of a negative delta wave in inferior leads; and precordial lead transition to R/S >1.
Results:
The ECG of fasciculoventricular pathways shows a variable pattern. It shares some features with an anteroseptal accessory pathway and others with a midseptal accessory pathway. A narrower QRS width was the most important variable in distinguishing a fasciculoventricular pathway from a septally located AV bypass tract (P <.0001). The angle between the QRS and the delta wave frontal plane axis could differentiate a fasciculoventricular pathway from an anteroseptal bypass tract (P <.0001) but not from a midseptal accessory pathway.
Conclusions:
The sinus rhythm ECG of patients with fasciculoventricular pathways shows similarities with ECGs of patients with anteroseptal and midseptal accessory pathways, but the QRS complex usually is narrower. The ECG recorded during sinus rhythm cannot reliably differentiate fasciculoventricular pathways with a broad QRS complex from anteroseptal or midseptal bypass tracts.
More Related Videos
08:19Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping
Published on: February 22, 2018
06:57Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction
Published on: January 31, 2019
Related Concept Videos
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
01:28Electrocardiogram Fundamentals
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin to...
01:29Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
01:19Electrophysiology of Normal Cardiac Rhythm
01:25Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
01:30Dysrhythmias V: Evaluating Dysrhythmias