Atrioventricular block electrocardiogram: Difference between revisions

Jump to navigation Jump to search
No edit summary
 
(15 intermediate revisions by 4 users not shown)
Line 1: Line 1:
__NOTOC__
__NOTOC__
{{Atrioventricular block}}
{{Atrioventricular block}}
{{CMG}}
{{CMG}}; {{AE}} {{EdzelCo}}
== Overview ==


== Atrioventricular Block Electrocardiogram ==
==Overview==


===First degree AV block EKG Examples===
== Electrocardiogram==
----
The main diagnostic modality used in determining whether a person has heart block, is the [[electrocardiogram]].
Shown below is an EKG image showing [[sinus rhythm]] with a [[prolonged PR interval]] (>200ms.) which is first degree A/V block. There is also a [[left axis deviation]] (axis between -30 and -90 degrees) with [[r waves]] in the [[Electrocardigram#Leads|inferior leads]]. This [[electrocardiogram#Axis|axis deviation]] is consistent with a left anterior fasicular block.
* First degree heart block consists of a [[prolonged PR interval]] of more than >200msec.
* Second degree heart block consists of [[Mobitz type I]] and [[Mobitz type II]] heart block.
** Mobitz I or [[Wenckebach block]] will show a progressive prolongation of the PR interval, until a ventricular beat is missed.
** Mobitz II AV block consists of a constant PR interval with intermittent missed beats.
* [[Complete heart block]] or third degree heart block will be depicted by a complete disassociation of atrial and ventricular beats.
 
==EKG Examples==
===First Degree AV Block EKG Examples===
Shown below is an EKG image showing [[sinus rhythm]] with a [[prolonged PR interval]] (>200ms.) which is [[first degree AV block]]. There is also a [[left axis deviation]] (axis between -30 and -90 degrees) with [[r waves]] in the [[Electrocardigram#Leads|inferior leads]]. This [[electrocardiogram#Axis|axis deviation]] is consistent with a left anterior fasicular block.
[[File:AVBlockEKG.jpg|center|500px]]
[[File:AVBlockEKG.jpg|center|500px]]
Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/index.php?title=Special:NewFiles&offset=&limit=500
Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/Main_Page


----
----


===Second degree AV block EKG Examples===
===Second Degree AV Block EKG Examples===


=====Mobitz I Second degree AV block EKG Examples=====
=====Mobitz I Second Degree AV Block EKG Examples=====
Shown below is an EKG image of ventriculophasic reflex during second degree AV block Mobitz I. The PP interval that follow upon the blocked sinus beat is prolonged.
Shown below is an EKG image of ventriculophasic reflex during second degree AV block Mobitz I. The PP interval where the blocked sinus beat occurs, is prolonged.
[[File:Ventriculophasic_Reflex.jpg|500px|center]]
[[File:Ventriculophasic_Reflex.jpg|500px|center]]
Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/File:De-Ventrfascreflex.jpg
Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/File:De-Ventrfascreflex.jpg
Line 27: Line 34:
----
----


=====Mobitz II Second degree AV block EKG Examples=====
=====Mobitz II Second Degree AV Block EKG Examples=====
Shown below is an EKG image of two-to-one AV block, which can represent benign block within the [[AV node]] or disease of the [[His-Purkinje system]]. Certain electrocardiographic features and maneuvers can help in distinguishing where the location of block exists. A [[PR prolongation|long PR interval]] with a narrow QRS suggests an intranodal block. A [[PR interval#Changes in PR interval|short PR interval]] with intraventricular conduction delay or bundle branch block suggests disease below the node. Responses to [[atropine]], exercise and [[carotid sinus massage]] can be helpful in diagnosis. [[Atropine]] will improve AV nodal conduction but will worsen block within diseased His-Purkinje fibers. Exercise has a similar effect, improving conduction in cases where block exists only in the node, but worsening when block is subnodal. Alternatively, [[Carotid Sinus Massage]] will slow conduction when block occurs in the AV node, but will improve conduction in diseased His-Purkinje tissue by allowing for refractoriness to recover.
Shown below is an EKG image of two-to-one AV block, which can represent benign block within the [[AV node]] or disease of the [[His-Purkinje system]]. Certain electrocardiographic features and maneuvers can help in distinguishing where the location of block exists. A [[PR prolongation|long PR interval]] with a narrow QRS suggests an intranodal block. A [[PR interval#Changes in PR interval|short PR interval]] with intraventricular conduction delay or bundle branch block suggests disease below the node. Responses to [[atropine]], exercise and [[carotid sinus massage]] can be helpful in diagnosis. [[Atropine]] will improve AV nodal conduction but will worsen block within diseased His-Purkinje fibers. Exercise has a similar effect, improving conduction in cases where block exists only in the node, but worsening when block is subnodal. Alternatively, [[Carotid Sinus Massage]] will slow conduction when block occurs in the AV node, but will improve conduction in diseased His-Purkinje tissue by allowing for refractoriness to recover.
[[Image:2to1AVBlock1.jpg|500px|center]]
[[Image:2to1AVBlock1.jpg|500px|center]]
Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/index.php?title=Special:NewFiles&offset=&limit=500
Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/Main_Page
 
----


===Third degree AV block EKG Examples===
'''For more EKG examples of First Degree AV Block click [[Atrioventricular block EKG examples|here]]'''
Shown below is an EKG image of third degree AV block. AV dissociation is present: there is no relation between [[p-waves]] and the (nodal) [[QRS complexes]].
[[File:3rd_Degree_AV_Block_1.png|500px|center]]
Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/File:De-Rhythm_3rdAVblock.png
 
==Sources==
Copyleft images obtained courtesy of ECGpedia, http://en.ecgpedia.org/index.php?title=Special:NewFiles&offset=&limit=500


==References==
==References==
Line 47: Line 46:
{{WH}}
{{WH}}
{{WS}}
{{WS}}
[[CME Category::Cardiology]]
[[Category:Electrophysiology]]
[[Category:Cardiology]]
[[Category:Disease]]
[[Category:Needs overview]]

Latest revision as of 16:03, 7 July 2022

Atrioventricular block Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Atrioventricular block from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

EKG Examples

Chest X Ray

Echocardiography

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Atrioventricular block electrocardiogram On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Atrioventricular block electrocardiogram

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Atrioventricular block electrocardiogram

CDC on Atrioventricular block electrocardiogram

Atrioventricular block electrocardiogram in the news

Blogs on Atrioventricular block electrocardiogram

Directions to Hospitals Treating Atrioventricular block

Risk calculators and risk factors for Atrioventricular block electrocardiogram

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Edzel Lorraine Co, DMD, MD[2]

Overview

Electrocardiogram

The main diagnostic modality used in determining whether a person has heart block, is the electrocardiogram.

  • First degree heart block consists of a prolonged PR interval of more than >200msec.
  • Second degree heart block consists of Mobitz type I and Mobitz type II heart block.
    • Mobitz I or Wenckebach block will show a progressive prolongation of the PR interval, until a ventricular beat is missed.
    • Mobitz II AV block consists of a constant PR interval with intermittent missed beats.
  • Complete heart block or third degree heart block will be depicted by a complete disassociation of atrial and ventricular beats.

EKG Examples

First Degree AV Block EKG Examples

Shown below is an EKG image showing sinus rhythm with a prolonged PR interval (>200ms.) which is first degree AV block. There is also a left axis deviation (axis between -30 and -90 degrees) with r waves in the inferior leads. This axis deviation is consistent with a left anterior fasicular block.

Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/Main_Page


Second Degree AV Block EKG Examples

Mobitz I Second Degree AV Block EKG Examples

Shown below is an EKG image of ventriculophasic reflex during second degree AV block Mobitz I. The PP interval where the blocked sinus beat occurs, is prolonged.

Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/File:De-Ventrfascreflex.jpg


Shown below are two rhythm strips showing Mobitz I A/V block with a gradual increase in the PR interval before the dropped p wave. Note the 2:1 block in the lower strip, and that one can not use this to determine if the block is Mobitz I or II as more than one conducted P wave is required to do this.

Copyleft image obtained courtesy of ECGpedia,http://en.ecgpedia.org/wiki/File:E267.jpg


Mobitz II Second Degree AV Block EKG Examples

Shown below is an EKG image of two-to-one AV block, which can represent benign block within the AV node or disease of the His-Purkinje system. Certain electrocardiographic features and maneuvers can help in distinguishing where the location of block exists. A long PR interval with a narrow QRS suggests an intranodal block. A short PR interval with intraventricular conduction delay or bundle branch block suggests disease below the node. Responses to atropine, exercise and carotid sinus massage can be helpful in diagnosis. Atropine will improve AV nodal conduction but will worsen block within diseased His-Purkinje fibers. Exercise has a similar effect, improving conduction in cases where block exists only in the node, but worsening when block is subnodal. Alternatively, Carotid Sinus Massage will slow conduction when block occurs in the AV node, but will improve conduction in diseased His-Purkinje tissue by allowing for refractoriness to recover.

Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/Main_Page

For more EKG examples of First Degree AV Block click here

References

Template:WH Template:WS CME Category::Cardiology