Third Degree AV Block (Complete Heart Block)


  • Today's Paramedic quote:

    Blood goes round and round; air goes in and out; any variation from this is bad. - Paramedic 101.

  • PARAMEDIC HELP

    • Paramedic Study Notes
    • Paediatric Emergency Notes
    • ECG Tutorial
  • PARAMEDIC INFO

    • Ambulance FAQs
    • Ambulance News
    • Anatomy and Physiology
    • Chest Pain
    • Emergency Management
    • Health
    • Laughter is the Best Medicine
    • Medical Disorders
    • Medical Eponyms
    • Medical Liability
    • Medical Science
    • Medical Signs
    • Medical Syndromes
    • New Technologies
    • Paramedic Case Studies
    • Paramedic Education
    • Paramedic Equipment
    • Paramedic Exam Preparation
    • Paramedic Jobs
    • Paramedic Skills
    • Pathophysiology
    • Patient Assessment
    • Real Paramedic Stories
    • Trauma Assessment

Third Degree AV Block (Complete Heart Block)

A Third Degree AV Block (Complete Heart Block) is where there is a complete conduction block between the atria and the venticles, which results in no correlation between contractions of either the atria or the ventricles. A Third Degree AV Block is a life threatening emergency, and if left untreated can result in sudden cardiac death syndrome. Treatment requires cardiac pacing through either an emergency external pacemaker or an internal pacemaker.

Third Degree AV Block (Complete Heart Block) ECG

Heart Rate: the atrial rate is likely to be normal (60-100 per minute), where as the ventricle rate is usually as low as 30-40 beats per minute.

Rhythm: the ventricular rhythm is essentially regular.

Pacemaker Site: there are two pacemaker sites. The SA node, which allows the atrium to contract, and depending on the site of the AV blockageĀ the AV junction or ventricles will be the main pacemaker site for the ventricles.

QRS Complexes: normal or abnormal.

3rd Degree AV Block

Third Degree AV Block (Complete Heart Block) Signs and Symptoms

The person is likely to look poorly perfused. Symptoms will include: dizziness, chest pain, chest tightness, shortness of breath andĀ palpitations.

Return to: ECG Interpretation Tutorial.

Next page in the ECG Interpretation Tutorial:

Ventricular Escape Rhythm



Copyright: Emergency Medical Paramedic 2010-2018. All rights reserved.
All information is provided for educational purposes only and should not be taken as medical advice.
Authors  Privacy Policy  Disclaimer  Advertising Policy  Contact Us  Our Goals