PMID- 9475580
OWN - NLM
STAT- MEDLINE
DCOM- 19980326
LR  - 20190909
IS  - 1045-3873 (Print)
IS  - 1045-3873 (Linking)
VI  - 9
IP  - 1
DP  - 1998 Jan
TI  - Increased dispersion of repolarization time determined by monophasic action 
      potentials in two patients with familial idiopathic ventricular fibrillation.
PG  - 74-83
AB  - INTRODUCTION: The role of increased dispersion of repolarization in the genesis 
      of torsades de pointes in patients with long QT syndrome has been clarified, but 
      its role in the genesis of idiopathic ventricular fibrillation (VF) is not yet 
      known. To investigate the pathogenesis of VF, we recorded monophasic action 
      potentials (MAPs) from two siblings (48- and 36-year-old males) with familial 
      idiopathic VF. METHODS AND RESULTS: The elder brother (patient 1) showed a late 
      r' wave in lead V1 and ST segment elevation in leads V1 through V3. The younger 
      brother (patient 2) had late r' waves and ST segment elevation in leads II, III, 
      and aVF, and the configurations were very similar to those of patient 1. MAPs 
      were recorded from several sites in the right ventricular (RV) and left 
      ventricular (LV) endocardium during constant right atrial pacing. The 
      repolarization time (RT) was defined as the sum of the activation time (AT) and 
      action potential duration (APD) at 90% repolarization. In patient 1, marked 
      prolongation of the AT (140 msec) and the RT (380 msec) was recorded in the RV 
      septum of the outflow tract, and the RT dispersion was markedly increased (125 
      msec). In contrast, patient 2 showed prolongation of the AT (80 msec) and RT (310 
      msec), and fractionated electrograms in the RV floor of the inflow tract. The RT 
      dispersion was also increased (80 msec). VF and nonsustained polymorphic 
      ventricular tachycardia were induced by double premature stimulation in patients 
      1 and 2, respectively. Chronic amiodarone therapy decreased the RT dispersion and 
      suppressed the induction of ventricular tachyarrhythmias in patient 2, although 
      late r' waves and slight ST segment elevation were unmasked in leads V1 and V2. 
      CONCLUSION: Our data suggest that the increased dispersion of the RT, which was 
      due mainly to a localized conduction delay in the RV, created an arrhythmogenic 
      substrate in the two patients with familial idiopathic VF.
FAU - Matsuo, K
AU  - Matsuo K
AD  - Division of Cardiology, Department of Internal Medicine, National Cardiovascular 
      Center, Osaka, Japan.
FAU - Shimizu, W
AU  - Shimizu W
FAU - Kurita, T
AU  - Kurita T
FAU - Suyama, K
AU  - Suyama K
FAU - Aihara, N
AU  - Aihara N
FAU - Kamakura, S
AU  - Kamakura S
FAU - Shimomura, K
AU  - Shimomura K
LA  - eng
PT  - Case Reports
PT  - Journal Article
PL  - United States
TA  - J Cardiovasc Electrophysiol
JT  - Journal of cardiovascular electrophysiology
JID - 9010756
RN  - 0 (Anti-Arrhythmia Agents)
RN  - N3RQ532IUT (Amiodarone)
SB  - IM
MH  - Action Potentials/physiology
MH  - Adult
MH  - Amiodarone/therapeutic use
MH  - Anti-Arrhythmia Agents/therapeutic use
MH  - Electric Stimulation
MH  - Electrocardiography
MH  - Electrophysiology
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Ventricular Fibrillation/drug therapy/genetics/*physiopathology
EDAT- 1998/02/25 00:00
MHDA- 1998/02/25 00:01
CRDT- 1998/02/25 00:00
PHST- 1998/02/25 00:00 [pubmed]
PHST- 1998/02/25 00:01 [medline]
PHST- 1998/02/25 00:00 [entrez]
AID - 10.1111/j.1540-8167.1998.tb00869.x [doi]
PST - ppublish
SO  - J Cardiovasc Electrophysiol. 1998 Jan;9(1):74-83. doi: 
      10.1111/j.1540-8167.1998.tb00869.x.