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Related Concept Videos

Electrocardiogram Fundamentals01:28

Electrocardiogram Fundamentals

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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...
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ECG Interpretation of Rhythms01:24

ECG Interpretation of Rhythms

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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....
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Electrocardiogram01:29

Electrocardiogram

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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...
9.1K
Correlation between ECG and Cardiac Cycle01:25

Correlation between ECG and Cardiac Cycle

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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...
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Dysrhythmias V: Evaluating Dysrhythmias01:30

Dysrhythmias V: Evaluating Dysrhythmias

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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...
427
Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias IV: Characteristics of Bradyarrhythmias

778
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...
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In Vivo Surface Electrocardiography for Adult Zebrafish
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QRS-T angle: a review.

Andrew Oehler1, Trevor Feldman, Charles A Henrikson

  • 1Internal Medicine Department, Oregon Health and Science University, Portland, OR.

Annals of Noninvasive Electrocardiology : the Official Journal of the International Society for Holter and Noninvasive Electrocardiology, Inc
|September 10, 2014
PubMed
Summary

The QRS-T angle, an electrocardiogram measure, offers a better way to predict cardiac events like sudden cardiac death than ejection fraction alone. This review highlights its predictive power for future cardiac morbidity and mortality.

Keywords:
cardiac arrestclinicalelectrocardiographyelectrophysiologynoninvasive techniquessudden death

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

  • Cardiology
  • Biomedical Engineering

Background:

  • Current cardiac risk stratification often relies on reduced ejection fraction.
  • There is a need for more robust methods to identify individuals at high risk for cardiac events.
  • The QRS-T angle, derived from electrocardiogram (ECG) data, has emerged as a potential prognostic marker.

Purpose of the Study:

  • To review the utility of the QRS-T angle in predicting future cardiac events.
  • To evaluate the QRS-T angle as a risk stratification tool beyond ejection fraction.
  • To explore the prognostic value of both frontal and spatial QRS-T angles.

Main Methods:

  • Review of observational studies investigating the QRS-T angle.
  • Analysis of ECG-derived QRS-T angle measurements.
  • Correlation of QRS-T angle with cardiac outcomes.

Main Results:

  • The QRS-T angle reflects the difference between depolarization and repolarization vectors.
  • Multiple studies demonstrate an association between abnormal QRS-T angles and adverse cardiac outcomes.
  • The QRS-T angle predicts sudden cardiac death, all-cause mortality, and cardiac morbidity.

Conclusions:

  • The QRS-T angle is a valuable electrocardiogram-derived marker for cardiac risk stratification.
  • Incorporating QRS-T angle assessment can improve the distribution of preventative cardiac resources.
  • Frontal and spatial QRS-T angles show significant predictive capability for major adverse cardiac events.