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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...

Dysrhythmias IV: Characteristics of Bradyarrhythmias

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...

Dysrhythmias III: Characteristics of Dysrhythmias

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.

Disturbances in Heart Rhythm

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...

Dysrhythmias II: Classification of Tachyarrhythmias

Dysrhythmias II: Classification of Tachyarrhythmias

Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional...

Mechanism of Cardiac Arrhythmias

Mechanism of Cardiac Arrhythmias

Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.

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Related Experiment Video

Updated: Jul 15, 2026

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Published on: February 26, 2013

Broad complex atrial fibrillation.

Huck Chin Chew¹, Swee Han Lim

¹Department of Emergency Medicine, Singapore General Hospital, Singapore 169608, Singapore. chinnjing@pacific.net.sg

The American Journal of Emergency Medicine

|May 15, 2007

Summary

Broad complex atrial fibrillation, often linked to Wolff-Parkinson-White syndrome, requires careful management. Intravenous procainamide is the recommended treatment for stable patients, unlike calcium channel blockers which can worsen the arrhythmia.

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High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

Published on: July 29, 2011

Area of Science:

Cardiology
Electrophysiology

Background:

Broad complex atrial fibrillation (BCAF) poses management challenges and risks morbidity/mortality.
Prompt recognition and appropriate treatment are crucial for patient outcomes.

Observation:

A case series of 3 patients presenting with palpitations and rapid BCAF on ECG.
Initial management with calcium channel blockers in two patients led to complications and required cardioversion.
The third patient received intravenous procainamide, leading to successful management.

Findings:

All three patients were diagnosed with Wolff-Parkinson-White (WPW) syndrome.
WPW syndrome can present as BCAF and may decompensate with inappropriate rate control.
Intravenous procainamide is effective for rate control in hemodynamically stable BCAF of unknown origin, particularly in WPW.

Implications:

Highlights the critical importance of recognizing WPW syndrome in patients with BCAF.
Underscores the potential dangers of using calcium channel blockers for rate control in such cases.
Establishes procainamide as a key therapeutic agent for hemodynamically stable BCAF in the emergency setting.