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Related Concept Videos

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...
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Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding.
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
Dysrhythmias III: Characteristics of Dysrhythmias01:29

Dysrhythmias III: Characteristics of Dysrhythmias

Dysrhythmias, also known as arrhythmias, are irregular heart rhythms that result from abnormal electrical activity in the heart, affecting its ability to circulate blood efficiently. Tachyarrhythmias, a subset of dysrhythmias, are characterized by abnormally fast heart rates exceeding 100 beats per minute. Here are some types of tachyarrhythmias with their distinct ECG features:Sinus Tachycardia:Sinus tachycardia presents a regular heart rhythm with an increased rate of 101-180 beats per minute.
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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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Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions
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Beat-to-beat QT interval variability in children: normal and physiologic data.

Hirofumi Kusuki1, Marina Kuriki, Kayo Horio

  • 1Clinical Laboratory, Mie University Hospital, Japan. hiro.kusuki@gmail.com

Journal of Electrocardiology
|September 25, 2010
PubMed
Summary

QT interval variability index (QTVI) in children decreases with age, establishing age-specific standards. This aids in accurately assessing ventricular repolarization instability in pediatric patients.

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Area of Science:

  • Pediatric Cardiology
  • Cardiac Electrophysiology
  • Biomedical Engineering

Background:

  • QT interval variability is a key indicator of ventricular vulnerability.
  • Limited data exists on QT interval variability in pediatric populations.
  • Understanding pediatric QT variability is crucial for assessing cardiac risk.

Purpose of the Study:

  • To evaluate QT interval variability in infants and children.
  • To establish age-specific QT variability index (QTVI) standards for children aged 0-7 years.
  • To determine potential sex-specific differences in pediatric QTVI.

Main Methods:

  • Recruited 173 children (0-7 years) without intrinsic cardiac disease.
  • Calculated QT variability index (QTVI) from electrocardiograms.
  • Developed age-specific QTVI values, sex-specific classifications, and a growth curve.

Main Results:

  • QTVI demonstrated a significant age-dependent decrease from infancy to school age.
  • QTVI values stabilized after school age.
  • No significant sex-specific differences in QTVI were observed across age groups.

Conclusions:

  • Standardized, age-dependent QTVI values improve the accuracy of assessing ventricular repolarization instability in pediatric patients.
  • Established QTVI reference ranges provide a valuable tool for pediatric cardiac risk stratification.
  • This study provides essential normative data for QT variability in healthy children.