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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.

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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...

Dysrhythmias IV: Characteristics of Bradyarrhythmias

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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...

ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias

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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...

Disturbances in Heart Rhythm

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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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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

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Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

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A wide complex tachycardia with changing atrial activation sequence.

Romeo Ayou¹, Sharad Agarwal, Anthony Tang

¹Department of Electrophysiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada. romeo@mbox303.swipnet.se

Pacing and Clinical Electrophysiology : PACE

|March 18, 2011

Summary

Radiofrequency ablation for accessory pathways can alter atrial activation. A case report shows temporary intraatrial block from radiofrequency delivery changed activation sequences during tachycardia, successfully treated by ablation.

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Area of Science:

Cardiology
Electrophysiology
Medical Devices

Background:

Radiofrequency (RF) ablation is a standard treatment for accessory pathways causing tachycardia.
Changes in retrograde atrial activation sequence during RF ablation can indicate alternative mechanisms or conduction issues.
Understanding these changes is crucial for successful ablation outcomes.

Observation:

A case report details a patient undergoing RF ablation for a left-side accessory pathway.
RF energy delivered proximal to the accessory pathway insertion site caused a temporary complete intraatrial conduction block.
This block resulted in a noticeable change in the retrograde atrial activation sequence during ongoing tachycardia.

Findings:

The observed change in retrograde atrial activation sequence was attributed to a temporary intraatrial conduction block induced by RF delivery.
The tachycardia was successfully terminated by subsequent ablation at the accessory pathway's insertion site.
This suggests RF delivery proximal to the pathway can transiently disrupt atrial conduction.

Implications:

RF ablation parameters and energy delivery location are critical for avoiding unintended intraatrial conduction blocks.
Recognizing changes in atrial activation sequences during ablation can guide procedural adjustments.
This case highlights a specific mechanism that can alter tachycardia circuits during ablation, impacting therapeutic strategy.