PMID- 16113076
OWN - NLM
STAT- MEDLINE
DCOM- 20060123
LR  - 20200930
IS  - 0363-6135 (Print)
IS  - 0363-6135 (Linking)
VI  - 290
IP  - 1
DP  - 2006 Jan
TI  - Increased ventricular repolarization heterogeneity in patients with ventricular 
      arrhythmia vulnerability and cardiomyopathy: a human in vivo study.
PG  - H79-86
AB  - Increased repolarization heterogeneity can provide the substrate for reentrant 
      ventricular arrhythmias in animal models of cardiomyopathy. We hypothesized that 
      ventricular repolarization heterogeneity is also greater in patients with 
      cardiomyopathy and ventricular arrhythmia vulnerability (inducible ventricular 
      tachycardia or positive microvolt T wave alternans, VT/TWA) compared with a 
      similar patient population without ventricular arrhythmia vulnerability (no 
      VT/TWA). Endocardial and epicardial repolarization heterogeneity was measured in 
      patients with (n = 12) and without (n = 10) VT/TWA by using transvenous 
      26-electrode catheters placed along the anteroseptal right ventricular 
      endocardium and left ventricular epicardium. Local activation times (AT), 
      activation-recovery intervals (ARI), and repolarization times (RT) were measured 
      from unipolar electrograms. Endocardial RT dispersion along the apicobasal 
      ventricle was greater (P < 0.005) in patients with VT/TWA than in those without 
      VT/TWA because of greater ARI dispersion (P < 0.005). AT dispersion was similar 
      between the two groups. Epicardial RT dispersion along the apicobasal ventricle 
      was greater (P < 0.05) in patients with VT/TWA than in those without VT/TWA 
      because of greater ARI dispersion (P < 0.05). AT dispersion was similar between 
      the two groups. A plot of AT as a function of ARI revealed an inverse linear 
      relationship for no VT/TWA such that progressively later activation was 
      associated with progressively shorter ARI. The AT-ARI relationship was nonlinear 
      in VT/TWA. In conclusion, patients with cardiomyopathy and VT/TWA have greater 
      endocardial and epicardial repolarization heterogeneity than those without VT/TWA 
      without associated conduction slowing. The steep repolarization gradients in 
      VT/TWA may provide the substrate for functional conduction block and reentrant 
      ventricular arrhythmias.
FAU - Chauhan, Vijay S
AU  - Chauhan VS
AD  - Division of Cardiology, University Health Network and Mount Sinai Hospital, 
      Toronto, ON, Canada. vijay.chauhan@uhn.on.ca
FAU - Downar, Eugene
AU  - Downar E
FAU - Nanthakumar, Kumaraswamy
AU  - Nanthakumar K
FAU - Parker, John D
AU  - Parker JD
FAU - Ross, Heather J
AU  - Ross HJ
FAU - Chan, Wilson
AU  - Chan W
FAU - Picton, Peter
AU  - Picton P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20050819
PL  - United States
TA  - Am J Physiol Heart Circ Physiol
JT  - American journal of physiology. Heart and circulatory physiology
JID - 100901228
SB  - IM
CIN - Am J Physiol Heart Circ Physiol. 2006 Jan;290(1):H77-8. PMID: 16373596
MH  - Adult
MH  - Aged
MH  - Cardiomyopathies/*physiopathology
MH  - Electrocardiography/*methods
MH  - Electrophysiologic Techniques, Cardiac
MH  - Female
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Tachycardia, Ventricular/*physiopathology
MH  - Ventricular Dysfunction, Left/*physiopathology
EDAT- 2005/08/23 09:00
MHDA- 2006/01/24 09:00
CRDT- 2005/08/23 09:00
PHST- 2005/08/23 09:00 [pubmed]
PHST- 2006/01/24 09:00 [medline]
PHST- 2005/08/23 09:00 [entrez]
AID - 00648.2005 [pii]
AID - 10.1152/ajpheart.00648.2005 [doi]
PST - ppublish
SO  - Am J Physiol Heart Circ Physiol. 2006 Jan;290(1):H79-86. doi: 
      10.1152/ajpheart.00648.2005. Epub 2005 Aug 19.