Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Electrocardiogram

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 Studies

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...

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

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...

ECG Interpretation of Rhythms

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...

Electrocardiogram Fundamentals

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...

Correlation between ECG and Cardiac Cycle

Correlation between ECG and Cardiac Cycle

The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the 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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Allosteric ligands with distinct properties uncover tissue-specific physiological regulation mediated by free fatty acid receptor 2.

Science signaling·2026

Same author

A new standard framework for dermal exposure assessment.

Annals of work exposures and health·2026

Same author

Measurement of quality of stroke care with national electronic health records: a prospective cohort study during and after the COVID-19 pandemic.

BMJ open·2026

Same author

Regioselective Iridium-Catalyzed C(7)-H Borylation of Free <i>N</i>-H 6‑Fluoroquinolones.

ACS omega·2026

Same author

Effect of swimming mode on shielding of odor traces in turbulence.

ArXiv·2026

Same author

A hierarchical Bayesian model reveals increased precision weighting for afferent cardiac signals, and reduced anxiety, as a function of interoceptive training.

Biological psychology·2026

Search research articles

Related Experiment Video

Updated: Jun 18, 2026

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia

Published on: September 16, 2017

Electrocardiogram QT interval increases in acute stroke.

James Mulcahy¹, Paul Johnson, Martin James

¹Musgrove Park Hospital, Taunton, UK. docjimboy @ yahoo.co.uk

Cerebrovascular Diseases (Basel, Switzerland)

|December 4, 2009

Summary

This summary is machine-generated.

Acute stroke increases QTmax and QTmin, indicating cardiac autonomic dysfunction. This study compared pre- and post-stroke ECGs to reveal these changes in QT intervals.

More Related Videos

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Published on: November 24, 2016

Related Experiment Videos

Last Updated: Jun 18, 2026

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia

Published on: September 16, 2017

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Published on: November 24, 2016

Area of Science:

Cardiology
Neurology
Medical Research

Background:

Previous studies show increased QT interval in acute stroke patients compared to controls.
Limited evidence exists for a causal link between stroke and ECG changes due to prior studies examining QT interval only post-stroke.

Purpose of the Study:

To investigate the change in QT interval around the time of acute stroke.
To compare pre- and post-stroke electrocardiograms (ECGs) to assess QT interval alterations.

Main Methods:

Retrospective observational study analyzing pre- and post-stroke ECGs from 45 acute stroke patients.
Measured QT interval from all leads, identifying QTmax (longest) and QTmin (shortest) for each ECG.

Main Results:

Significant mean increase observed in QTmax (14.9 ms) and QTmin (10.8 ms) post-stroke.
No significant difference in QT changes based on stroke subtype or side.
No significant confounding variables identified through regression analysis.

Conclusions:

Acute stroke is associated with an increase in QTmax and QTmin, suggesting an impact on cardiac autonomic function.
The observed QT interval increase is likely due to acute stroke effects, not confounding factors.
Further research with larger cohorts may explore relationships between QT disturbances and stroke characteristics.