The Pinwheel Experiment Revisited: Effects of Cellular Electrophysiological Properties on Vulnerability to Cardiac Reentry.
From: Cardiovascular Research Laboratory, David Geffen School of Medicine, University of California, Los Angeles 90095, USA.
American journal of physiology. Heart and circulatory physiology
- Publish Date: Sep 2007
- ISSN: 0363-6135
- Volume: 293
- Issue: 3
- Pages: H1781-90
- Medium: Print
- Language: English
- Citation (JAMA): Yang Ming-Jim, Tran Diana X, Weiss James N, et al. The Pinwheel Experiment Revisited: Effects of Cellular Electrophysiological Properties on Vulnerability to Cardiac Reentry.. Am. J. Physiol. Heart Circ. Physiol. Sep 2007;293:H1781-90
Abstract
In normal heart, ventricular fibrillation can be induced by a single properly timed strong electrical or mechanical stimulus. A mechanism first proposed by Winfree and coined the “pinwheel experiment” emphasizes the timing and strength of the stimulus in inducing figure-of-eight reentry. However, the effects of cellular electrophysiological properties on vulnerability to reentry in the pinwheel scenario have not been investigated. In this study, we extend Winfree’s pinwheel experiment to show how the vulnerability to reentry is affected by the graded action potential responses induced by a strong premature stimulus, action potential duration (APD), and APD restitution in simulated monodomain homogeneous two-dimensional tissue. We find that a larger graded response, longer APD, or steeper APD restitution slope reduces the vulnerable window of reentry. Strong graded responses and long APD promote tip-tip interactions at long coupling intervals, causing the two initiated spiral wave tips to annihilate. Steep APD restitution promotes wave front-wave back interaction, causing conduction block in the central common pathway of figure-of-eight reentry. We derive an analytical treatment that shows good agreement with numerical simulation results.
Mesh Headings (Keywords): Action Potentials, Animals, Arrhythmias, Cardiac, Electric Stimulation, Electrophysiology, Heart, Heart Conduction System, Humans, Models, Biological, Ventricular Fibrillation
Check for Full Text / PubMed Unique Identifier (PMID): 17586622
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