Journal of Postgraduate Medicine
 Open access journal indexed with Index Medicus & ISI's SCI  
Users online: 1623  
Home | Subscribe | Feedback | Login 
About Latest Articles Back-Issues Article Submission Resources Sections Etcetera Contact
 
  NAVIGATE Here 
  Search
 
 :: Next article
 :: Previous article 
 :: Table of Contents
  
 RESOURCE Links
 ::  Similar in PUBMED
 ::  Search Pubmed for
 ::  Search in Google Scholar for
 ::  Article in PDF (137 KB)
 ::  Citation Manager
 ::  Access Statistics
 ::  Reader Comments
 ::  Email Alert *
 ::  Add to My List *
* Registration required (free) 

  IN THIS Article
 ::  References
 ::  Article Figures

 Article Access Statistics
    Viewed3896    
    Printed94    
    Emailed1    
    PDF Downloaded182    
    Comments [Add]    

Recommend this journal


 


 
LETTERS
Year : 2007  |  Volume : 53  |  Issue : 2  |  Page : 148-149

Blocked or delayed atrioventricular nodal conduction due to concealed conduction due to interpolated ventricular ectopics


Department of Cardiology, Institute of Cardiovascular Disease, Madras Medical Mission, 4A, Dr. JJ Nagar, Mogappair, Chennai - 600 037, India

Correspondence Address:
A R Udyavar
Department of Cardiology, Institute of Cardiovascular Disease, Madras Medical Mission, 4A, Dr. JJ Nagar, Mogappair, Chennai - 600 037
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0022-3859.32224

Rights and Permissions




How to cite this article:
Udyavar A R, Pandurangi U M. Blocked or delayed atrioventricular nodal conduction due to concealed conduction due to interpolated ventricular ectopics. J Postgrad Med 2007;53:148-9

How to cite this URL:
Udyavar A R, Pandurangi U M. Blocked or delayed atrioventricular nodal conduction due to concealed conduction due to interpolated ventricular ectopics. J Postgrad Med [serial online] 2007 [cited 2019 Oct 14];53:148-9. Available from: http://www.jpgmonline.com/text.asp?2007/53/2/148/32224


Sir,

Concealed conduction commonly occurs when an interpolated premature ventricular impulse enters the His Purkinje system and atrioventricular (AV) node retrogradely but does not reach the atrium. As a consequence, the ensuing sinus impulse either does not conduct to the ventricle or conducts with a prolonged PR interval due to the increased AV nodal refractoriness. This effect of the extra-systole on AV conduction of the next sinus impulse should not be misdiagnosed as an AV block.[1] We report the case of a 20-year-old gentleman who was referred for palpitations at rest. We advised him a 24h Holter monitoring for further workup. Some Holter strips are shown in [Figure - 1].

The top strip reveals interpolated ventricular extra-systoles in bigeminal rhythm with prolonged PR interval in sinus beats that follow the premature complexes. The same phenomenon occurs in the middle strip, but here sinus beats that closely follow the premature ones undergo a progressive PR interval prolongation ending in the block of a sinus impulse (the third sinus P wave).

The bottom strip of [Figure - 1] again reveals interpolated ventricular ectopics (PVCs) occurring in bigeminal rhythm; due to the effect of retrograde concealed penetration of the PVC into the AV junction, the ensuing sinus impulses are alternatively conducted and blocked. The concept of concealed conduction was introduced by Langendorf.[2] The term was applied whenever penetration of an impulse into a defined cardiac structure was not immediately evident at the surface electrocardiogram, but could only be recognized by its after effects on formation or conduction of the ensuing impulse. The definition of concealed conduction has been irrevocably altered by the availability of intracardiac recordings,[3] that may, at times, directly demonstrate the conduction of an impulse into a defined cardiac structure, despite this not being evident at the surface ECG. Although the AV node is the site most commonly associated with concealed conduction, this phenomenon can occur in any section of the heart.[3]

Concealed conduction often occurs when a PVC enters the His Purkinje system and the AV node retrogradely but does not reach the atrium. As a consequence, the next sinus impulse either does not conduct to the ventricle or conducts with PR interval prolongation.[1] The present case demonstrates how interpolated PVCs can have totally different effects on AV nodal conduction of the ensuing sinus impulse as a result of different patterns of concealed retrograde conduction. These patients should not be misdiagnosed as having advanced AV block.[4],[5]

 
 :: References Top

1.Prystowsky EN, Klein GJ. Cardiac arrhythmias: An Integrated Approach for the Clinician.1st ed. McGraw-Hill Inc: New York; 1994.  Back to cited text no. 1    
2.Langendorf R, Pick A. Concealed conduction further evaluation of a fundamental aspect of propagation of the cardiac impulse. Circulation 1956;13:381-99.  Back to cited text no. 2  [PUBMED]  
3.Josephson ME. Clinical Cardiac Electrophysiology; Techniques and Interpretations. 3rd ed. Lippincott Williams and Wilkins: Philadelphia (PA); 2002.  Back to cited text no. 3    
4.Barold SS, Hayes DL. Second-degree atrioventricular block: A reappraisal. Mayo Clin Proc 2001;76:44-57.  Back to cited text no. 4  [PUBMED]  
5.Wang K, Salerno DM. Pseudo AV block secondary to concealed premature His bundle depolarizations. Am Heart J 1991;121:1236-7.  Back to cited text no. 5  [PUBMED]  


    Figures

  [Figure - 1]



 

Top
Print this article  Email this article
Previous article Next article
Online since 12th February '04
2004 - Journal of Postgraduate Medicine
Official Publication of the Staff Society of the Seth GS Medical College and KEM Hospital, Mumbai, India
Published by Wolters Kluwer - Medknow