scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Rotors and the Dynamics of Cardiac Fibrillation

01 Mar 2013-Circulation Research (Lippincott Williams & Wilkins)-Vol. 112, Iss: 5, pp 849-862
TL;DR: Examination of recent evidence suggesting that rotors are critical in sustaining both atrial and ventricular fibrillation in the human heart and its implications for treatment with radiofrequency ablation is examined.
Abstract: The objective of this article is to present a broad review of the role of cardiac electric rotors and their accompanying spiral waves in the mechanism of cardiac fibrillation. At the outset, we present a brief historical overview regarding reentry and then discuss the basic concepts and terminologies pertaining to rotors and their initiation. Thereafter, the intrinsic properties of rotors and spiral waves, including phase singularities, wavefront curvature, and dominant frequency maps, are discussed. The implications of rotor dynamics for the spatiotemporal organization of fibrillation, independent of the species being studied, are described next. The knowledge gained regarding the role of cardiac structure in the initiation or maintenance of rotors and the ionic bases of spiral waves in the past 2 decades, as well as the significance for drug therapy, is reviewed subsequently. We conclude by examining recent evidence suggesting that rotors are critical in sustaining both atrial and ventricular fibrillation in the human heart and its implications for treatment with radiofrequency ablation.
Citations
More filters
Journal ArticleDOI
TL;DR: This 2017 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a writing group, convened by these five international societies.

1,626 citations

Journal ArticleDOI
TL;DR: The working group proposes the following working definition of atrial cardiomyopathy: ‘Any complex of structural, architectural, contractile or electrophysiological changes affecting the atria with the potential to produce clinically-relevant manifestations’ (Table 1).

530 citations


Cites background from "Rotors and the Dynamics of Cardiac ..."

  • ...lation is a consequence of the continued activity of a few vortices (rotors) that spin at high frequencies, generating ‘fibrillatory conduction’ [236,237]....

    [...]

Journal ArticleDOI
TL;DR: In this article, the authors focus on the relationship between the autonomic nervous system and the pathophysiology of atrial fibrillation and the potential benefit and limitations of neuromodulation in the management of this arrhythmia.
Abstract: Autonomic nervous system activation can induce significant and heterogeneous changes of atrial electrophysiology and induce atrial tachyarrhythmias, including atrial tachycardia and atrial fibrillation (AF). The importance of the autonomic nervous system in atrial arrhythmogenesis is also supported by circadian variation in the incidence of symptomatic AF in humans. Methods that reduce autonomic innervation or outflow have been shown to reduce the incidence of spontaneous or induced atrial arrhythmias, suggesting that neuromodulation may be helpful in controlling AF. In this review, we focus on the relationship between the autonomic nervous system and the pathophysiology of AF and the potential benefit and limitations of neuromodulation in the management of this arrhythmia. We conclude that autonomic nerve activity plays an important role in the initiation and maintenance of AF, and modulating autonomic nerve function may contribute to AF control. Potential therapeutic applications include ganglionated plexus ablation, renal sympathetic denervation, cervical vagal nerve stimulation, baroreflex stimulation, cutaneous stimulation, novel drug approaches, and biological therapies. Although the role of the autonomic nervous system has long been recognized, new science and new technologies promise exciting prospects for the future.

504 citations

References
More filters
Journal ArticleDOI
TL;DR: The pulmonary veins are an important source of ectopic beats, initiating frequent paroxysms of atrial fibrillation and these foci respond to treatment with radio-frequency ablation.
Abstract: Background Atrial fibrillation, the most common sustained cardiac arrhythmia and a major cause of stroke, results from simultaneous reentrant wavelets. Its spontaneous initiation has not been studied. Methods We studied 45 patients with frequent episodes of atrial fibrillation (mean [±SD] duration, 344±326 minutes per 24 hours) refractory to drug therapy. The spontaneous initiation of atrial fibrillation was mapped with the use of multielectrode catheters designed to record the earliest electrical activity preceding the onset of atrial fibrillation and associated atrial ectopic beats. The accuracy of the mapping was confirmed by the abrupt disappearance of triggering atrial ectopic beats after ablation with local radio-frequency energy. Results A single point of origin of atrial ectopic beats was identified in 29 patients, two points of origin were identified in 9 patients, and three or four points of origin were identified in 7 patients, for a total of 69 ectopic foci. Three foci were in the right atrium...

7,487 citations

Book
01 Sep 1990
TL;DR: Part I - Molecular Bases Of Ion Channel Activity PART II - Biophysics and Regulation of Cardiac Ion Channels PART III - Pharmacology of Card cardiac Ion Ch channels PART IV - Cellular Electrophysiology PART V - Models of Cardiopulmonary Excitation PART VI - Neural Control ofCardiac Electrical Activity
Abstract: "Cardiac Electrophysiology: From Cell to Bedside" defines the entire state of current scientific and clinical knowledge in this subspecialty. In response to the many major recent developments in the field, Drs. Zipes and Jalife have completely updated this modern classic, making the 5th Edition the most significant revision yet. From our latest understanding of ion channels, molecular genetics, and cardiac electrical activity through newly recognized syndromes, unique needs of special patient populations, and new diagnostic and therapeutic options, you'll find all the state-of-the-art guidance you need to make informed, effective clinical decisions. What's more, a significantly restructured organization, a new full-color layout, and full-text online access make reference easier than ever.

2,423 citations

Journal ArticleDOI
TL;DR: The major cellular structures involved in E-C coupling include myofilaments, Na/Ca exchange and the sarcolemmal Ca-pump as mentioned in this paper, as well as the sources and sinks of activator calcium.
Abstract: 1. Major cellular structures involved in E-C coupling. 2. Myofilaments: The end effector of E-C Coupling. 3. Sources and sinks of activator calcium. 4. Cardiac action potentials and ion channels. 5. Ca influx via sarcolemmal Ca channels. 6. Na/Ca exchange and the sarcolemmal Ca-pump. 7. Sarcoplasmic reticulum Ca uptake, content and release. 8. Excitation-contraction coupling. 9. Control of cardiac contraction by SR and sarcolemmal Ca fluxes. 10. Cardiac inotropy and Ca mismanagement. References. Index.

1,724 citations

Journal ArticleDOI
TL;DR: The model provides the basis for the study of arrhythmogenic activity of the single myocyte including afterdepolarizations and triggered activity and can simulate cellular responses under different degrees of Ca2+ overload.
Abstract: A mathematical model of the cardiac ventricular action potential is presented. In our previous work, the membrane Na+ current and K+ currents were formulated. The present article focuses on processes that regulate intracellular Ca2+ and depend on its concentration. The model presented here for the mammalian ventricular action potential is based mostly on the guinea pig ventricular cell. However, it provides the framework for modeling other types of ventricular cells with appropriate modifications made to account for species differences. The following processes are formulated: Ca2+ current through the L-type channel (ICa), the Na(+)-Ca2+ exchanger, Ca2+ release and uptake by the sarcoplasmic reticulum (SR), buffering of Ca2+ in the SR and in the myoplasm, a Ca2+ pump in the sarcolemma, the Na(+)-K+ pump, and a nonspecific Ca(2+)-activated membrane current. Activation of ICa is an order of magnitude faster than in previous models. Inactivation of ICa depends on both the membrane voltage and [Ca2+]i. SR is divided into two subcompartments, a network SR (NSR) and a junctional SR (JSR). Functionally, Ca2+ enters the NSR and translocates to the JSR following a monoexponential function. Release of Ca2+ occurs at JSR and can be triggered by two different mechanisms, Ca(2+)-induced Ca2+ release and spontaneous release. The model provides the basis for the study of arrhythmogenic activity of the single myocyte including afterdepolarizations and triggered activity. It can simulate cellular responses under different degrees of Ca2+ overload. Such simulations are presented in our accompanying article in this issue of Circulation Research.

1,612 citations

Journal ArticleDOI
TL;DR: Simulation of the membrane action potential of the mammalian ventricular cell shows the importance of the slow recovery of INa in determining the response of the cell and relates these phenomena to the underlying ionic channel kinetics.
Abstract: A mathematical model of the membrane action potential of the mammalian ventricular cell is introduced. The model is based, whenever possible, on recent single-cell and single-channel data and incorporates the possibility of changing extracellular potassium concentration [K]o. The fast sodium current, INa, is characterized by fast upstroke velocity (Vmax = 400 V/sec) and slow recovery from inactivation. The time-independent potassium current, IK1, includes a negative-slope phase and displays significant crossover phenomenon as [K]o is varied. The time-dependent potassium current, IK, shows only a minimal degree of crossover. A novel potassium current that activates at plateau potentials is included in the model. The simulated action potential duplicates the experimentally observed effects of changes in [K]o on action potential duration and rest potential. Physiological simulations focus on the interaction between depolarization and repolarization (i.e., premature stimulation). Results demonstrate the importance of the slow recovery of INa in determining the response of the cell. Simulated responses to periodic stimulation include monotonic Wenckebach patterns and alternans at normal [K]o, whereas at low [K]o nonmonotonic Wenckebach periodicities, aperiodic patterns, and enhanced supernormal excitability that results in unstable responses ("chaotic activity") are observed. The results are consistent with recent experimental observations, and the model simulations relate these phenomena to the underlying ionic channel kinetics.

1,438 citations


"Rotors and the Dynamics of Cardiac ..." refers methods in this paper

  • ...In simulations, they used a 2D sheet of ventricular cells incorporating the 1991 kinetics of Luo and Rudy.(47) For experiments, they used a thin slice of sheep ventricular epicardium; the slice was perfused with a voltage-sensitive dye and optically mapped....

    [...]

  • ...In simulations, they used a 2D sheet of ventricular cells incorporating the 1991 kinetics of Luo and Rudy.47 For experiments, they used a thin slice of sheep ventricular epicardium; the slice was perfused with a voltage-sensitive dye and optically mapped.46 An artificial linear obstacle was etched into the ventricular muscle sheet in both simulations and experiments (depicted in a cartoon in Figure 2B, where the obstacle is represented by a red line)....

    [...]