Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Sign Test for Nominal Data01:12

Sign Test for Nominal Data

177
The sign test is a nonparametric method used to evaluate hypotheses about the median of a single sample or to compare the medians of two related samples. The sign test is particularly useful when dealing with nominal data, which includes distinct categories without an inherent order, such as names, labels, and preferences. Nominal data restricts statistical analysis to evaluating population proportions rather than mean or median values that require continuous data.
For example, consider a...
177
Introduction to the Sign Test01:10

Introduction to the Sign Test

1.1K
The sign test is an important tool in nonparametric statistics, offering a straightforward yet effective method for analyzing matched pairs, nominal data, or hypotheses concerning the median of a population. It transforms data points into positive or negative signs, avoiding the need for assumptions about data distribution and instead focusing on the direction of change. It is particularly valuable when data does not conform to the normal distribution requirements of many parametric tests. For...
1.1K
Sign Convention01:30

Sign Convention

2.7K
When analyzing a beam subjected to various loads, it is crucial to understand the internal forces and moments generated within the structure. These internal forces can be broadly classified into normal forces, shear forces, and bending moments. To determine these forces and moments, we use the method of sections and apply a specific sign convention based on their direction and the side of the section being analyzed.
The normal force acts perpendicular to the beam's cross-section and can...
2.7K
Sign Test for Median of Single Population01:20

Sign Test for Median of Single Population

199
In general, the sign test serves as a nonparametric method to test hypotheses about the median of a single population when the data does not follow a known distribution. This simplicity makes it particularly useful for small sample sizes or when the assumptions of parametric tests cannot be met. The process begins with identifying a null hypothesis, typically stating that the population median equals a specific value. The alternative hypothesis could be that the median is either not equal to,...
199
Sign Test for Matched Pairs01:17

Sign Test for Matched Pairs

229
The sign test for matched pairs offers a robust method for comparing two paired samples, often for the effects of an intervention in one of them. This method is very useful in situations where the underlying distribution of the data is unknown. The test compares two related samples—often pre- and post-treatment measurements on the same subjects—to determine if there are significant differences in their median values.
To conduct the sign test, we first calculate the differences in...
229
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

4.2K
The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a...
4.2K

You might also read

Related Articles

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

Sort by
Same author

Controversy: pulsed field ablation is the standard technique for all the candidates for atrial fibrillation ablation.

Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology·2025
Same author

Racial and Ethnic Disparities in the Use and Outcomes With WATCHMAN FLX: A SURPASS Analysis of the NCDR Left Atrial Appendage Occlusion Registry.

Journal of the American Heart Association·2024
Same author

Catheter ablation for atrial fibrillation in patients with prior left atrial appendage occlusion device.

Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing·2024
Same author

Catheter-related and clinical complications associated with QDOT MICRO<sup>TM</sup> Ablation Catheter.

Journal of cardiovascular electrophysiology·2024
Same author

Step-by-step recommendations utilizing four-dimensional intracardiac echocardiography in left atrial appendage procedures.

Journal of cardiovascular electrophysiology·2024
Same author

New-generation electronic appliances and cardiac implantable electronic devices: a systematic literature review of mechanisms and in vivo studies.

Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing·2024
Same journal

R1 Prognostic Significance of T-Wave Amplitude Variability for Adverse Cardiovascular Outcomes: A Systematic Review and Meta-Analysis.

Journal of arrhythmia·2026
Same journal

Pacing the Impossible: ICE- and Voltage-Guided Atrial Leadless Pacemaker Implantation in Double Mechanical Valve Disease.

Journal of arrhythmia·2026
Same journal

A Case of Rotator Cuff Tear Owing to External Electrical Cardioversion.

Journal of arrhythmia·2026
Same journal

Predictors and Outcomes of 30-Day Readmissions Following Electrical Cardioversion for Atrial Fibrillation: Insights From the Nationwide Readmissions Database.

Journal of arrhythmia·2026
Same journal

Documented Obstructive Sleep Apnea, Cardiometabolic Phenotype, and Rhythm-Related Outcomes After Atrial Fibrillation Ablation: An Observational Cohort Study.

Journal of arrhythmia·2026
Same journal

Longitudinal Dissociation of the Left Bundle Branch: Two Different Patterns of S-V Isoelectric Interval.

Journal of arrhythmia·2026
See all related articles

Related Experiment Video

Updated: Oct 17, 2025

Flapping Soft Fin Deformation Modeling using Planar Laser-Induced Fluorescence Imaging
06:20

Flapping Soft Fin Deformation Modeling using Planar Laser-Induced Fluorescence Imaging

Published on: April 28, 2022

2.3K

Shark fin sign.

Manne Janaki Rami Reddy1, Jalaj Garg1

  • 1Division of Cardiology Cardiac Arrhythmia Service Medical College of Wisconsin Milwaukee WI USA.

Journal of Arrhythmia
|October 8, 2021
PubMed
Summary
This summary is machine-generated.

This case study highlights the rare "shark fin sign" on electrocardiograms (ECGs). This sign, characterized by diffuse ST-segment elevations, indicated multivessel coronary vasospasm secondary to hemopericardium.

More Related Videos

Image Rendering Techniques in Postmortem Computed Tomography: Evaluation of Biological Health and Profile in Stranded Cetaceans
12:32

Image Rendering Techniques in Postmortem Computed Tomography: Evaluation of Biological Health and Profile in Stranded Cetaceans

Published on: September 27, 2020

9.5K
High-throughput DNA Extraction and Genotyping of 3dpf Zebrafish Larvae by Fin Clipping
10:12

High-throughput DNA Extraction and Genotyping of 3dpf Zebrafish Larvae by Fin Clipping

Published on: June 29, 2018

14.4K

Related Experiment Videos

Last Updated: Oct 17, 2025

Flapping Soft Fin Deformation Modeling using Planar Laser-Induced Fluorescence Imaging
06:20

Flapping Soft Fin Deformation Modeling using Planar Laser-Induced Fluorescence Imaging

Published on: April 28, 2022

2.3K
Image Rendering Techniques in Postmortem Computed Tomography: Evaluation of Biological Health and Profile in Stranded Cetaceans
12:32

Image Rendering Techniques in Postmortem Computed Tomography: Evaluation of Biological Health and Profile in Stranded Cetaceans

Published on: September 27, 2020

9.5K
High-throughput DNA Extraction and Genotyping of 3dpf Zebrafish Larvae by Fin Clipping
10:12

High-throughput DNA Extraction and Genotyping of 3dpf Zebrafish Larvae by Fin Clipping

Published on: June 29, 2018

14.4K

Area of Science:

  • Cardiology
  • Medical Diagnostics

Background:

  • The electrocardiogram (ECG) is a critical tool for diagnosing cardiac conditions.
  • Specific ECG findings can indicate rare or complex pathologies.

Purpose of the Study:

  • To report a case demonstrating the
  • shark fin sign
  • an unusual ECG pattern.
  • To correlate this sign with multivessel coronary vasospasm secondary to hemopericardium.

Main Methods:

  • Case report analysis.
  • Electrocardiogram (ECG) interpretation.
  • Review of clinical presentation and etiology.

Main Results:

  • The patient presented with diffuse tombstone-like QRS-ST segment elevations in inferior and anterolateral leads, consistent with the "shark fin sign."
  • These transient ECG changes were attributed to multivessel coronary vasospasm.
  • The vasospasm was likely secondary to hemopericardium.

Conclusions:

  • The "shark fin sign" on ECG can be a marker for significant underlying cardiac events.
  • This specific ECG finding in the case was indicative of multivessel coronary vasospasm.
  • Hemopericardium should be considered as a potential cause for such vasospasm and associated ECG changes.