Watanabe I, Okumura Y, Nagashima K, Ohkubo K, Ashino S, Kofune M, Ohya T, Hirayama A. Electrical remodeling in fibrillating canine atrium: action potential alternans during rapid atrial pacing and late phase 3 early afterdepolarization after cessation of rapid atrial pacing.
Int Heart J 2010;
51:354-8. [PMID:
20966609 DOI:
10.1536/ihj.51.354]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Sustained atrial fibrillation (AF) was induced by atrial burst pacing, and monophasic action potentials (MAPs) were recorded. MAP alternans was observed at a cycle length (CL) of 167.5 ± 28.2 msec before burst pacing and 201.3 ± 40.2 msec after burst pacing. AF > 5 minutes duration was induced in 1 dog in the control condition but in all 8 dogs after burst pacing. The difference in RA MAPD(80) of the first spontaneous beat and steady-state sinus rhythm was significantly larger after atrial burst pacing than before atrial burst pacing (31.5 ± 15.9 msec versus 8.2 ± 9.0 msec) In 4 dogs, late phase 3 early after depolarization was observed after rapid atrial pacing. Rapid atrial pacing-induced electrical remodeling includes APD alternans during rapid atrial pacing and also causes an increase in the MAPD of the initial several beats and the development of late phase 3 early afterdepolarizations after a sudden increase in CL.
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