Unexcitable zones as a source of spiral waves initiation and cardiac arrhythmias

2002 ◽  
Author(s):  
J.M. Starobin ◽  
Y.I. Zilberter ◽  
C.F. Starmer
Keyword(s):  
Cardiac Arrhythmias ◽  
Spiral Waves

scholarly journals Phase synchrony reveals organization in human atrial fibrillation

2015 ◽  
Vol 309 (12) ◽  
pp. H2118-H2126 ◽  
Author(s):  
David Vidmar ◽  
Sanjiv M. Narayan ◽  
Wouter-Jan Rappel
Keyword(s):  
Atrial Fibrillation ◽  
Cardiac Arrhythmias ◽  
Spatial Dynamics ◽  
Spiral Waves ◽  
Temporal Organization ◽  
Coarse Grained ◽  
Phase Synchrony ◽  
Activation Times ◽  
High Phase ◽  
Human Atrial Fibrillation

It remains unclear if human atrial fibrillation (AF) is spatially nonhierarchical or exhibits a hierarchy of organization sustained by sources. We utilize activation times obtained at discrete locations during AF to compute the phase synchrony between tissue regions, to examine underlying spatial dynamics throughout both atria. We construct a binary synchronization network and show that this network can accurately define regions of coherence in coarse-grained in silico data. Specifically, domains controlled by spiral waves exhibit regions of high phase synchrony. We then apply this analysis to clinical data from patients experiencing cardiac arrhythmias using multielectrode catheters to simultaneously record from a majority of both atria. We show that pharmaceutical intervention with ibutilide organizes activation by increasing the size of the synchronized domain in AF and quantify the increase in temporal organization when arrhythmia changes from fibrillation to tachycardia. Finally, in recordings from 24 patients in AF we show that the level of synchrony is spatially broad with some patients showing large spatially contiguous regions of synchronization, while in others synchrony is localized to small pockets. Using computer simulations, we show that this distribution is inconsistent with distributions obtained from simulations that mimic multiwavelet reentry but is consistent with mechanisms in which one or more spatially conserved spiral waves is surrounded by tissue in which activation is disorganized.

scholarly journals Overdrive pacing of spiral waves in a model of human ventricular tissue

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sergei F. Pravdin ◽  
Timofei I. Epanchintsev ◽  
Alexander V. Panfilov
Keyword(s):  
Cardiac Arrhythmias ◽  
Cardiac Tissue ◽  
Low Voltage ◽  
Spiral Waves ◽  
High Frequency Stimulation ◽  
In Silico Study ◽  
Restitution Curve ◽  
Life Threatening ◽  
Frequency Stimulation ◽  
Human Cardiac Tissue

AbstractHigh-voltage electrical defibrillation remains the only reliable method of quickly controlling life-threatening cardiac arrhythmias. This paper is devoted to studying an alternative approach, low-voltage cardioversion (LVC), which is based on ideas from non-linear dynamics and aims to remove sources of cardiac arrhythmias by applying high-frequency stimulation to cardiac tissue. We perform a detailed in-silico study of the elimination of arrhythmias caused by rotating spiral waves in a TP06 model of human cardiac tissue. We consider three parameter sets with slopes of the APD restitution curve of 0.7, 1.1 and 1.4, and we study LVC at the baseline and under the blocking of INa and ICaL and under the application of the drugs verapamil and amiodarone. We show that pacing can remove spiral waves; however, its efficiency can be substantially reduced by dynamic instabilities. We classify these instabilities and show that the blocking of INa and the application of amiodarone increase the efficiency of the method, while the blocking of ICaL and the application of verapamil decrease the efficiency. We discuss the mechanisms and the possible clinical applications resulting from our study.

Sleep and cardiac arrhythmias

1972 ◽  
Vol 130 (5) ◽  
pp. 751-753 ◽  
Author(s):  
R. Smith
Keyword(s):  
Cardiac Arrhythmias

Cardiac arrhythmias related to psychiatric medication

2017 ◽  
Vol 36 (09) ◽  
pp. 747-750
Author(s):  
R. W. Freudenmann ◽  
C. Schönfeldt-Lecuona ◽  
B. J. Connemann ◽  
M. Gahr ◽  
M. Elsayed
Keyword(s):  
Cardiac Arrhythmias ◽  
Torsade De Pointes ◽  
General Medicine ◽  
Fold Increase ◽  
Cardiac Risk ◽  
Psychiatric Medication ◽  
Cardiac Side Effects ◽  
Torsade De Pointes Tachycardia ◽  
Multiple Drugs ◽  
Available Information

SummaryThis narrative review summarizes current available information about cardiac arrhythmias (QT prolongation, Torsade de pointes Tachycardia [TdP], sudden cardiac death) associated with psychiatric medication. Among the most commonly used antipsychotics, amisulpride and ziprasidone are most frequently associated with TdP. Treatment with some antidepressants (SSRIs, tricyclic antidepressants) is associated with a 5- to 6-fold increase in the incidence of out-of-hospital cardiac arrest. Lithium is associated with bradycardia, T-wave changes and AV-block; anxiolytics of the benzodiazepine group do usually not have cardiac side effects. The combination of multiple drugs (including medications from general medicine) that prolong the QT interval has a particularly high cardiac risk.

Entrainment and Annihilation of Reentrant Excitation in a Periodically Stimulated Ring of Excitable Media

1997 ◽  
Vol 36 (04/05) ◽  
pp. 290-293
Author(s):  
L. Glass ◽  
T. Nomura
Keyword(s):  
Cardiac Arrhythmias ◽  
Initial Phase ◽  
Human Heart ◽  
Periodic Wave ◽  
Excitable Media ◽  
One Dimensional ◽  
Clinical Observations ◽  
Periodic Stimulation ◽  
Reentrant Excitation ◽  
Stimulation Of

Abstract:Excitable media, such as nerve, heart and the Belousov-Zhabo- tinsky reaction, exhibit a large excursion from equilibrium in response to a small but finite perturbation. Assuming a one-dimensional ring geometry of sufficient length, excitable media support a periodic wave of circulation. As in the periodic stimulation of oscillations in ordinary differential equations, the effects of periodic stimuli of the periodically circulating wave can be described by a one-dimensional Poincaré map. Depending on the period and intensity of the stimulus as well as its initial phase, either entrainment or termination of the original circulating wave is observed. These phenomena are directly related to clinical observations concerning periodic stimulation of a class of cardiac arrhythmias caused by reentrant wave propagation in the human heart.

Does valproic acid cause cardiac arrhythmias, in particular QT-prolongations, as possible SUDEP risk factor?

2006 ◽  
Vol 37 (06) ◽  
Author(s):  
A Fues ◽  
S Vlaho ◽  
M Baz Bartels ◽  
V Boda ◽  
S Dittrich ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Risk Factor ◽  
Cardiac Arrhythmias
Sign in / Sign up

Export Citation Format

Share Document