PMID- 29514866
OWN - NLM
STAT- MEDLINE
DCOM- 20190930
LR  - 20190930
IS  - 1708-8267 (Electronic)
IS  - 1081-5589 (Linking)
VI  - 66
IP  - 5
DP  - 2018 Jun
TI  - Intramyocardial block in patients with atrioventricular block.
PG  - 1-4
LID - 10.1136/jim-2017-000682 [doi]
AB  - Atrioventricular (AV) block has been extensively studied. However, conduction 
      inside the myocardium in patients with AV block has not been reported. In this 
      study, we aimed to demonstrate the presence of intramyocardial block in patients 
      with AV block. Five consecutive patients with spontaneous high-grade AV block and 
      Torsades de pointes (TdP) were prospectively studied with standard United States 
      Catheter Instruments (USCI) endocardial temporary catheter located at the right 
      ventricle (RV) apex. The morphology of endocardial potentials observed in the 
      basic QRS complexes as well as during episodes of TdP was studied. The 
      electrogram (EGM) of the basic rhythm showed a sharp deflection of high amplitude 
      preceded and/or followed by a smooth potential of low amplitude interpreted as 
      far-field potentials in all patients. The sharp potential can be observed at the 
      beginning, in the middle or at the end of the smooth potential. All these 
      potentials were reproduced from beat to beat and were falling inside the QRS 
      complex of the surface ECG. Therefore, these aspects are zones of electrically 
      depressed or silent myocardium larger than the interelectrode distance of 12 mm. 
      This situation is in agreement with recent genetic factors. In this study, we 
      demonstrated for the first time that patients with spontaneous AV block also have 
      trouble in ventricular activation located on the AV conduction system and inside 
      the myocardium. It is then possible to speculate that the presence of diffuse 
      non-conducting myocardium explains why most TdPs do not degenerate into 
      ventricular fibrillation (VF) and generally stop spontaneously.
CI  - (c) American Federation for Medical Research (unless otherwise stated in the text 
      of the article) 2018. All rights reserved. No commercial use is permitted unless 
      otherwise expressly granted.
FAU - Li, Guoliang
AU  - Li G
AD  - Unite de Rythmologie, Institut de Cardiologie, Hopital de la Salpetriere, Paris, 
      France.
AD  - Department of Cardiovascular Medicine, Xi'an Jiaotong University Medical College, 
      Xi'an, Shaanxi, China.
FAU - Saguner, Ardan M
AU  - Saguner AM
AD  - Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland.
FAU - Akdis, Deniz
AU  - Akdis D
AD  - Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland.
FAU - Fontaine, Guy H
AU  - Fontaine GH
AD  - Unite de Rythmologie, Institut de Cardiologie, Hopital de la Salpetriere, Paris, 
      France.
LA  - eng
PT  - Journal Article
DEP - 20180307
PL  - England
TA  - J Investig Med
JT  - Journal of investigative medicine : the official publication of the American 
      Federation for Clinical Research
JID - 9501229
SB  - IM
EIN - J Investig Med. 2018 Oct;66(7):1068. PMID: 30254037
MH  - Action Potentials
MH  - Atrioventricular Block/*pathology/physiopathology
MH  - Electrodes
MH  - Humans
MH  - Myocardium/*pathology
MH  - Signal Processing, Computer-Assisted
OTO - NOTNLM
OT  - cardiology
COIS- Competing interests: None declared.
EDAT- 2018/03/09 06:00
MHDA- 2019/10/01 06:00
CRDT- 2018/03/09 06:00
PHST- 2018/02/04 00:00 [accepted]
PHST- 2018/03/09 06:00 [pubmed]
PHST- 2019/10/01 06:00 [medline]
PHST- 2018/03/09 06:00 [entrez]
AID - jim-2017-000682 [pii]
AID - 10.1136/jim-2017-000682 [doi]
PST - ppublish
SO  - J Investig Med. 2018 Jun;66(5):1-4. doi: 10.1136/jim-2017-000682. Epub 2018 Mar 
      7.