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

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...
Disturbances in Heart Rhythm01:29

Disturbances in Heart Rhythm

Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...

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In Vivo Surface Electrocardiography for Adult Zebrafish
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ECGs with small QRS voltages.

Ting Ting Low1, Voon Shiong Ronnie Tan, Swee-Guan Teo

  • 1Cardiac Department, National University Heart Centre, National University of Singapore, Singapore.

Singapore Medical Journal
|May 16, 2012
PubMed
Summary

Low voltage complexes on an electrocardiogram (ECG) can indicate critical conditions like cardiac amyloidosis or cardiac tamponade. Early ECG screening is vital for diagnosing these serious, often hidden, heart issues.

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Area of Science:

  • Cardiology
  • Diagnostic Imaging
  • Internal Medicine

Background:

  • Low voltage complexes on electrocardiograms (ECG) are often overlooked but can signify serious underlying pathologies.
  • The ECG remains a valuable, noninvasive tool for screening critical cardiac conditions.

Observation:

  • Two patient cases with low voltage complexes on ECG are presented.
  • Case 1: ECG findings and echocardiogram led to diagnosing cardiac amyloidosis.
  • Case 2: ECG screening identified cardiac tamponade due to pericardial effusion.

Findings:

  • Low voltage ECG findings can be indicative of rare and life-threatening conditions.
  • Diagnostic correlation with echocardiography is crucial for accurate diagnosis.
  • ECG is a critical first step in identifying emergent cardiac issues.

Implications:

  • Recognizing low voltage complexes on ECG is essential for timely diagnosis and intervention.
  • This highlights the continued importance of the ECG in clinical practice for detecting critical cardiac diseases.
  • Prompt diagnosis of conditions like cardiac amyloidosis and tamponade can significantly improve patient outcomes.