PMID- 12030349
OWN - NLM
STAT- MEDLINE
DCOM- 20021106
LR  - 20190819
IS  - 1346-9843 (Print)
IS  - 1346-9843 (Linking)
VI  - 66
IP  - 5
DP  - 2002 May
TI  - Afterdepolarizations promote the transition from ventricular tachycardia to 
      fibrillation in a three-dimensional model of cardiac tissue.
PG  - 505-10
AB  - Recent experimental results regarding the action potential duration restitution 
      curve have explained the transition from ventricular tachycardia (VT) to 
      fibrillation (VF) in terms of spiral wave (SW) meandering and breakup. However, 
      it remains unclear whether VF always has a steep restitution curve. The present 
      study was designed to test the hypothesis that afterdepolarizations occur at 
      excitable gaps during VF and affect the SW dynamics, even if the restitution 
      curve is gentle. Homogeneous and isotropic 3-dimensional tissue was simulated 
      with a LRd model. Because of the gentle restitution curve, it was not expected 
      that SW instabilities would occur in this condition. In the tissue, a stationary 
      SW reentry was initially observed; however, afterdepolarizations erupted from the 
      excitable gap near the SW tip, and the SW then meandered widely. Following that, 
      afterdepolarizations erupted far from the SW tip, resulting in SW breakup. In 
      this manner, the wave dynamics degenerated into a chaotic state within a few 
      seconds. Furthermore, not only triggered activity but also subthreshold 
      afterdepolarizations were found to cause SW instabilities. These results suggest 
      that afterdepolarizations may play an important role in the transition to VF and 
      that the mechanism is independent of restitution properties.
FAU - Ashihara, Takashi
AU  - Ashihara T
AD  - First Department of Internal Medicine, Shiga University of Medical Science, Otsu, 
      Japan. ash@belle.shigamed.ac.jp
FAU - Yao, Takenori
AU  - Yao T
FAU - Namba, Tsunetoyo
AU  - Namba T
FAU - Kawase, Ayaka
AU  - Kawase A
FAU - Ikeda, Takanori
AU  - Ikeda T
FAU - Nakazawa, Kazuo
AU  - Nakazawa K
FAU - Ito, Makoto
AU  - Ito M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Japan
TA  - Circ J
JT  - Circulation journal : official journal of the Japanese Circulation Society
JID - 101137683
SB  - IM
MH  - Computer Simulation
MH  - Electrocardiography
MH  - Electrophysiology
MH  - Humans
MH  - *Models, Cardiovascular
MH  - Tachycardia, Ventricular/*complications/physiopathology
MH  - Ventricular Fibrillation/*etiology/physiopathology
EDAT- 2002/05/28 10:00
MHDA- 2002/11/26 04:00
CRDT- 2002/05/28 10:00
PHST- 2002/05/28 10:00 [pubmed]
PHST- 2002/11/26 04:00 [medline]
PHST- 2002/05/28 10:00 [entrez]
AID - 10.1253/circj.66.505 [doi]
PST - ppublish
SO  - Circ J. 2002 May;66(5):505-10. doi: 10.1253/circj.66.505.