| Possible mechanism of ECG features in patients with idiopathic ventricular fibrillation studied by heart model and computer simulation. | |
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MedLine Citation:
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PMID: 9535486 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The possible contribution of localized conduction delay and abnormal action potentials to ventricular fibrillation (VF) was studied by applying an anisotropic cardiac computer model to clinical cases of the Brugada-type electrocardiogram (ECG), which shows right bundle branch block (RBBB), a normal QT interval, ST-segment elevation, and late r' in leads V1 and V2. The anisotropic heart model was composed of 50,000 discrete units with a spatial resolution of 1.5 mm and was mounted in a human torso model. The longitudinal/transverse conduction velocity ratio was 3:1. For the normal ECG, a conduction velocity of 0.75 m/s was required. In the abnormal area of the right anterior epicardial wall, the conduction velocity was set at 0.2 m/s, with decreasing action potential amplitude and 10% prolonged action potential duration. The ECG features of ST-segment elevation and Brugada-type right bundle branch block pattern were simulated. The action potential duration was able to change dynamically with coupling interval of stimulation, with a ratio of 9% for normal ventricular muscle and 50% for Purkinje fibers. Five successive stimuli were applied to the left lateral epicardium 300 ms after the first sinus excitation, and sustained VF was induced with the transmural conduction delay at the right anterior ventricle as a block increasing the vulnerability. At the initiation of VF, reentry circuits were shown around the border zone of the right epicardium and were very heterogeneous around the conduction delayed area and septal area. In an area with the characteristics of nontransmural conduction delay, sustained VF was prevented, and the pattern of transient right bundle branch block appeared on the simulated ECG and body surface potential maps. The late r' wave was calculated in the precordial leads and right anterior site on the body surface potential maps. These results suggest that increased multipolarity in the border zone between the Purkinje fibers and delayed conduction area in the right ventricle might play an important role as a functional block for the persistence of VF. |
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Authors:
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O Okazaki; Y Yamauchi; M Kashida; K Izumo; N Akatsuka; S Ohnishi; M Shoda; T Nirei; H Kasanuki; M Ebato; S Mashima; K Harumi; D Wei |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Journal of electrocardiology Volume: 30 Suppl ISSN: 0022-0736 ISO Abbreviation: J Electrocardiol Publication Date: 1998 |
Date Detail:
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Created Date: 1998-05-28 Completed Date: 1998-05-28 Revised Date: 2009-11-11 |
Medline Journal Info:
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Nlm Unique ID: 0153605 Medline TA: J Electrocardiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 98-104 Citation Subset: IM |
Affiliation:
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Division of Cardiology, International Medical Center of Japan, Tokyo. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Action Potentials Anisotropy Body Surface Potential Mapping Bundle-Branch Block / complications, physiopathology Cardiac Pacing, Artificial Computer Simulation* Electrocardiography* Electrophysiology Heart Conduction System / physiopathology Heart Ventricles / physiopathology Humans Models, Cardiovascular Purkinje Fibers / physiopathology Ventricular Fibrillation / complications, physiopathology* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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