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Related Concept Videos

Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

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...
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ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias01:25

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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...
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Mechanism of Cardiac Arrhythmias01:28

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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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Dysrhythmias II: Classification of Tachyarrhythmias01:28

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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...
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Dysrhythmias III: Characteristics of Dysrhythmias01:29

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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...
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Syncope and paroxysmal atrioventricular block.

Milena Aste1, Michele Brignole1

  • 1Arrhythmology Center, Department of Cardiology, Ospedali del Tigullio, 16033 Lavagna, Italy.

Journal of Arrhythmia
|December 20, 2017
PubMed
Summary
This summary is machine-generated.

Three types of paroxysmal atrioventricular block (AVB) cause syncope: intrinsic, vagal, and idiopathic. Each has distinct features and varying responses to treatments like cardiac pacing and theophylline.

Keywords:
AdenosineIdiopathic atrioventricular blockParoxysmal atrioventricular blockSyncopeTheophylline

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Area of Science:

  • Cardiology
  • Electrophysiology
  • Internal Medicine

Background:

  • Paroxysmal atrioventricular block (AVB) is a significant cause of syncope.
  • Current literature categorizes AVB into intrinsic, vagal, and idiopathic types.
  • These types are associated with distinct clinical presentations and underlying mechanisms.

Purpose of the Study:

  • To differentiate the three primary types of paroxysmal AVB causing syncope.
  • To highlight the unique clinical and electrocardiographic features of each AVB type.
  • To compare the efficacy of cardiac pacing and theophylline therapy across these subtypes.

Main Methods:

  • Literature review of paroxysmal atrioventricular block and syncope.
  • Analysis of clinical and electrocardiographic characteristics of different AVB types.
  • Evaluation of treatment responses for cardiac pacing and theophylline.

Main Results:

  • Intrinsic AVB (Stokes-Adams attack) involves intrinsic conduction system disease.
  • Extrinsic vagal AVB relates to parasympathetic influence and reflex syncope.
  • Extrinsic idiopathic AVB is linked to low adenosine and low-adenosine syncope.
  • Distinct clinical and ECG features differentiate the three types.
  • Therapeutic efficacy of pacing and theophylline varies among the AVB subtypes.

Conclusions:

  • Understanding the specific type of paroxysmal AVB is crucial for effective syncope management.
  • Tailoring treatment strategies, including cardiac pacing and theophylline, based on AVB type can improve outcomes.
  • Further research into the mechanisms and treatments for each AVB subtype is warranted.