Related Experiment Video

Updated: Aug 12, 2026

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus
08:28

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus

Published on: April 5, 2011

Investigation of QT-interval dispersion in the electrocardiogram of 81 dogs

S G Dennis1, N J Summerfield, A Boswood

  • 1Section of Cardiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia 19104-6010, USA.

The Veterinary Record
|August 8, 2002
PubMed

Insights

This study established normal QT interval dispersion (QT dispersion) ranges in dogs, finding no significant difference in dogs with cardiac disease. Further research is needed due to potential measurement errors.

Area of Science:

  • Veterinary Cardiology
  • Electrophysiology
  • Cardiac Diagnostics

Background:

  • QT interval dispersion (QT dispersion) indicates ventricular repolarization inhomogeneity.
  • Increased QT dispersion is linked to sudden death and arrhythmias in human cardiac diseases.
  • QT dispersion has not been evaluated in canine populations.

Purpose of the Study:

  • To establish a normal reference range for QT dispersion in dogs.
  • To assess the impact of cardiac disease on QT dispersion in dogs.

Main Methods:

  • Ten-lead electrocardiograms (ECGs) were recorded from 81 dogs across two veterinary hospitals.
  • Data from 68 dogs (32 normal, 36 with cardiac disease) were analyzed.
  • QT dispersion and heart rate-corrected QT dispersion were calculated.

Main Results:

  • The mean QT dispersion was 20.8 (18.2 ms).
  • The mean heart rate-corrected QT dispersion was 26.1 (23.6 ms).
  • No significant effect of cardiac disease on QT dispersion was observed.

Conclusions:

  • This study provides initial reference values for canine QT dispersion.
  • Cardiac disease did not significantly alter QT dispersion in this cohort.
  • Potential measurement errors necessitate cautious interpretation and further validation.

More Related Videos

In Vivo Surface Electrocardiography for Adult Zebrafish09:13

In Vivo Surface Electrocardiography for Adult Zebrafish

Published on: August 1, 2019

Electrocardiogram Recordings in Anesthetized Mice using Lead II04:16

Electrocardiogram Recordings in Anesthetized Mice using Lead II

Published on: June 20, 2020

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...
Electrocardiogram Fundamentals01:28

Electrocardiogram Fundamentals

Introduction
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...
ECG Interpretation of Rhythms01:24

ECG Interpretation of Rhythms

An electrocardiogram (ECG)graphically represents the heart's electrical activity on ECG paper or a monitor.
Components of the Electrocardiogram
The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave.
ECG waveforms are divided by vertical and horizontal lines at standard intervals.
The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage. When...
Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias IV: Characteristics of Bradyarrhythmias

Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV...
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...
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...