Non-Linear Dynamics of Cardiac Alternans: Subcellular to Tissue-Level Mechanisms of Arrhythmia
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Keyword
T-wave alternanscalcium handling
cardiac alternans
pattern formation
repolarization alternans
subcellular alternans
Journal title
Frontiers in PhysiologyDate Published
2012Publication Volume
3
Metadata
Show full item recordAbstract
Cardiac repolarization alternans is a rhythm disturbance of the heart in which rapid stimulation elicits a beat-to-beat alternation in the duration of action potentials and magnitude of intracellular calcium transients in individual cardiac myocytes. Although this phenomenon has been identified as a potential precursor to dangerous reentrant arrhythmias and sudden cardiac death, significant uncertainty remains regarding its mechanism and no clinically practical means of halting its occurrence or progression currently exists. Cardiac alternans has well-characterized tissue, cellular, and subcellular manifestations, the mechanisms and interplay of which are an active area of research.Citation
Gaeta SA, Christini DJ. Non-linear dynamics of cardiac alternans: subcellular to tissue-level mechanisms of arrhythmia. Front Physiol. 2012 May 31;3:157. doi: 10.3389/fphys.2012.00157. PMID: 22783195; PMCID: PMC3389489.DOI
10.3389/fphys.2012.00157ae974a485f413a2113503eed53cd6c53
10.3389/fphys.2012.00157
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- Creative Commons
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivatives 4.0 International
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A Class of Monte-Carlo-Based Statistical Algorithms for Efficient Detection of Repolarization AlternansIravanian, S.; Kanu, U. B.; Christini, D. J. (Institute of Electrical and Electronics Engineers (IEEE), 2012-07)Cardiac repolarization alternans is an electrophysiologic condition identified by a beat-to-beat fluctuation in action potential waveform. It has been mechanistically linked to instances of T-wave alternans, a clinically defined ECG alternation in T-wave morphology, and associated with the onset of cardiac reentry and sudden cardiac death. Many alternans detection algorithms have been proposed in the past, but the majority have been designed specifically for use with T-wave alternans. Action potential duration (APD) signals obtained from experiments (especially those derived from optical mapping) possess unique characteristics, which requires the development and use of a more appropriate alternans detection method. In this paper, we present a new class of algorithms, based on the Monte Carlo method, for the detection and quantitative measurement of alternans. Specifically, we derive a set of algorithms (one an analytical and more efficient version of the other) and compare its performance with the standard spectral method and the generalized likelihood ratio test algorithm using synthetic APD sequences and optical mapping data obtained from an alternans control experiment. We demonstrate the benefits of the new algorithm in the presence of Gaussian and Laplacian noise and frame-shift errors. The proposed algorithms are well suited for experimental applications, and furthermore, have low complexity and are implementable using fixed-point arithmetic, enabling potential use with implantable cardiac devices.
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