EFFECT OF HETEROGENEITY ON SPIRAL WAVE DYNAMICS IN SIMULATED CARDIAC TISSUE

2004 ◽  
Vol 14 (09) ◽  
pp. 3363-3375 ◽  
Author(s):  
R. CASSIA-MOURA ◽  
FAGEN XIE ◽  
HILDA A. CERDEIRA
Keyword(s):  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Cardiac Arrhythmias ◽  
Cardiac Tissue ◽  
Spiral Wave ◽  
Clinical Context ◽  
Wave Dynamics ◽  
Heterogeneous Tissue ◽  
Anisotropic Conduction ◽  
Homogeneous Tissue

There is considerable spatial heterogeneity in the electrical properties of the heart muscle and there are indications that anisotropic conduction may play an important role in the pathogenesis of clinical cardiac arrhythmias. Spiral waves of electrical activity are related to reentrant cardiac arrhythmias as ventricular tachycardia and ventricular fibrillation, and the generation of a wave breakup is hypothesized to underlie the transition from ventricular tachycardia to ventricular fibrillation — the leading cause of sudden cardiac death. Here we investigate the effect of heterogeneity on spiral wave reentry in a two-dimensional modified FitzHugh–Nagumo membrane model. Spiral wave breakup induced by the heterogeneity is found. The spiral wave dynamics is invariant under translational and rotational transformations in homogeneous tissue, but for heterogeneous tissue, this symmetry is broken due to the heterogeneity. The reentry dynamics depends on the degree of heterogeneity and the point where the reentry is initiated within the simulated tissue. This study may open potentially exciting new diagnostic and therapeutic possibilities in a clinical context.

COMPLICATED ELECTRICAL ACTIVITIES IN CARDIAC TISSUE

2004 ◽  
Vol 18 (17n19) ◽  
pp. 2645-2650 ◽  
Author(s):  
YUO-HSIEN SHIAU ◽  
MING-PIN HSUEH ◽  
SHU-SHYA HSEU ◽  
HUEY-WEN YIEN
Keyword(s):  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Cardiac Tissue ◽  
Normal Sinus Rhythm ◽  
Conduction Block ◽  
Spiral Wave ◽  
Point Of View ◽  
Normal Sinus ◽  
Clinical Measurements ◽  
Electrical Activities

It has become widely accepted that ventricular fibrillation, the most dangerous cardiac arrhythmias, is a major cause of death in the industrialized world. Alternans and conduction block have recently been related to the progression from ventricular tachycardia to ventricular fibrillation. From the point of view in cellular electrophysiology, ventricular tachycardia is the formation of reentrant wave in cardiac tissue. And ventricular fibrillation arises from subsequent breakdown of reentrant wave into multiple drifting and meandering spiral waves. In this paper, we numerically study pulse and vortex dynamics in cardiac tissue. Our numerical results include 1:1 normal sinus rhythm, 2:1 conduction block, complete conduction block, spiral wave, and spiral breakup. All of our numerical findings can be corresponding to clinical measurements in electrocardiogram. Various electrical activities in cardiac tissue will be discussed in detail in the present manuscript.

Recognition and Management of Cardiac Arrhythmias: Part II. Ventricular Arrhythmias and Bradyarrhythmias

1998 ◽  
Vol 13 (2) ◽  
pp. 68-77
Author(s):  
Simon Chakko ◽  
Raul Mitrani
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Congestive Heart Failure ◽  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Cardiac Arrhythmias ◽  
Ventricular Arrhythmias ◽  
Qrs Complex ◽  
Implantable Defibrillators

This review discusses the treatment of ventricular arrhythmias and bradyarrhythmias. Recent studies addressing the management of nonsustained ventricular arrhythmias in patients with congestive heart failure and those recovering from myocardial infarction are discussed. Determination of the origin of wide QRS complex tachycardia is usually possible at the bedside and the diagnostic criteria are provided. Therapy to prevent recurrent ventricular tachycardia or ventricular fibrillation is difficult and controversial. A widely accepted approach based on electrophysiologic testing and implantable defibrillators appears to be the most effective. Recognition and management of common bradyarrhythmias including the indications for pacemakers are discussed.

Abstract 16223: Cardiac Arrhythmias in Hospitalized Patients With COVID-19

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Jae Hyung Cho ◽  
Ali Namazi ◽  
Richard Shelton ◽  
Archana Ramireddy ◽  
Ashkan Ehdaie ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Interleukin 6 ◽  
Cardiac Arrhythmias ◽  
Ventricular Arrhythmias ◽  
Sinus Tachycardia ◽  
Sustained Ventricular Tachycardia ◽  
Rhythm Disorder ◽  
Baseline Characteristics

Introduction: Arrhythmias have been reported frequent in COVID-19 patients, but the incidence and nature have not been well characterized. Hypothesis: Atrial and ventricular arrhythmias are common complications of patients with COVID-19. Methods: Patients admitted with COVID-19 and monitored by telemetry were prospectively enrolled in the study. Baseline characteristics, hospital course, treatment and complications were collected from the patients’ medical records. Telemetry was monitored to detect the incidence of cardiac arrhythmias. The incidence and types of cardiac arrhythmias were analyzed and compared between survivors and non-survivors. Results: Among 143 patients admitted with telemetry monitoring, overall in-hospital mortality was 23.1% (33/143 patients) during the period of observation (mean follow up 19.9 ± 13.7 days). Survivors were younger (68.1 ± 17.2 vs. 77.6 ± 15.9 years old, p=0.006), had higher body mass index (28.1 ± 8.3 vs. 24.3 ± 6.2, p=0.019), were less tachycardic on initial presentation (heart rate 90.6 ± 19.4 vs. 99.8 ± 23.7 bpm, p=0.026) and had lower troponin (peak troponin 0.03 vs. 0.14 ng/ml. p=0.006) and interleukin-6 levels (peak interleukin-6 32 vs. 264 pg/ml, p=0.001). Sinus tachycardia, the most common arrhythmia (occurring in 39.9% [57/143] of patients), occurred more frequently in non-survivors (57.6% vs. 34.5% in survivors, p=0.018). Premature ventricular complexes occurred in 28.7% (41/143), and non-sustained ventricular tachycardia in 15.4% (22/143) of patients, with no difference between survivors and non-survivors. Sustained ventricular tachycardia and ventricular fibrillation were rare (seen only in 1.4% and 0.7% of patients, respectively). Conclusions: In this prospective observational study of hospitalized and monitored patients with COVID-19, sinus tachycardia was the most common rhythm disorder, and its presence was associated with higher mortality. Sustained ventricular tachycardia or ventricular fibrillation were infrequent, contradicting previous reports that malignant ventricular arrhythmias are commonly seen in patients hospitalized with COVID-19.

scholarly journals Drift and termination of spiral waves in optogenetically modified cardiac tissue at sub-threshold illumination

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Sayedeh Hussaini ◽  
Vishalini Venkatesan ◽  
Valentina Biasci ◽  
José M Romero Sepúlveda ◽  
Raul A Quiñonez Uribe ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Dynamic Control ◽  
Spiral Wave ◽  
Deep Understanding ◽  
Spiral Waves ◽  
Mouse Heart ◽  
Cell Coupling ◽  
Wave Dynamics ◽  
Systematic Exploration ◽  
Voltage Gradients

The development of new approaches to control cardiac arrhythmias requires a deep understanding of spiral wave dynamics. Optogenetics offers new possibilities for this. Preliminary experiments show that sub-threshold illumination affects electrical wave propagation in the mouse heart. However, a systematic exploration of these effects is technically challenging. Here, we use state-of-the-art computer models to study the dynamic control of spiral waves in a two-dimensional model of the adult mouse ventricle, using stationary and non-stationary patterns of sub-threshold illumination. Our results indicate a light-intensity-dependent increase in cellular resting membrane potentials, which together with diffusive cell-cell coupling leads to the development of spatial voltage gradients over differently illuminated areas. A spiral wave drifts along the positive gradient. These gradients can be strategically applied to ensure drift-induced termination of a spiral wave, both in optogenetics and in conventional methods of electrical defibrillation.

scholarly journals Development of Antiarrhythmic Therapy-Resistant Ventricular Tachycardia, Ventricular Fibrillation, and Premature Ventricular Contractions in a 15-Year-Old Patient

2020 ◽  
Author(s):  
Can Yilmaz Yozgat ◽  
Osman Yesilbas ◽  
Akin Iscan ◽  
Ismail Yurtsever ◽  
Hafize Otcu Temur ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Cardiac Arrhythmias ◽  
Blood Pressure Monitoring ◽  
Cardiac Activity ◽  
Pulseless Electrical Activity ◽  
Left Ventricular ◽  
Premature Ventricular Contractions ◽  
Arterial Blood

AbstractSudden cardiac arrest (SCA) is the sudden cessation of regular cardiac activity so that the victim becomes unresponsive, with no signs of circulation and no normal breathing. Asystole, ventricular tachycardia (VT), ventricular fibrillation (VF), and pulseless electrical activity are the underlying rhythm disturbances in the pediatric age group. If appropriate interventions (cardiopulmonary resuscitation-CPR and/or defibrillation or cardioversion) are not performed rapidly, this condition progresses to sudden death. There have not been many reported cases of the approach and treatment of cardiac arrhythmias after SCA. Herein, we would like to report a case of a 15-year-old female patient with dilated cardiomyopathy (DCM) who was admitted to our clinic a year ago, and while her left ventricular systolic functions were improved, SCA suddenly occurred. Since the SCA event occurred in another city, intravenous treatment of amiodarone was done immediately and was switch to continuous infusion dose of amiodarone until the patient arrived at our institution's pediatric intensive care unit (PICU) 3 hours later. During the patient's 20-day PICU hospitalization, she developed pulseless VT and VF from time to time. The patient's pulseless VT and VF attacks were brought under control by the use of a defibrillator and added antiarrhythmic drugs (amiodarone, flecainide, esmolol, and propafenone). Intriguingly, therapy-resistance bigeminy with premature ventricular contractions (PVCs) continued despite all these treatments. The patient did not have adequate blood pressure measured by invasive arterial blood pressure monitoring while having bigeminy PVCs. The intermittent bigeminy PVCs ameliorated rapidly after intermittent boluses of lidocaine. In the end, multiple antiarrhythmic therapies and intermittent bolus lidocaine doses were enough to bring her cardiac arrhythmias after SCA under control. This case illustrates that malign PVC's should be taken very seriously, since they may predispose to the development of VT or VF. Also, this case highlights the importance of close vigilance of arterial pressure tracings of patients with bigeminy PVCs which develop after SCA and should not be accepted as normal.

scholarly journals Drift and termination of spiral waves in optogenetically modified cardiac tissue at sub-threshold illumination

2020 ◽  
Author(s):  
Sayedeh Hussaini ◽  
Vishalini Venkatesan ◽  
Valentina Biasci ◽  
José M. Romero Sepúlveda ◽  
Raúl A. Quiñonez Uribe ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Dynamic Control ◽  
Spiral Wave ◽  
Deep Understanding ◽  
Spiral Waves ◽  
Mouse Heart ◽  
Cell Coupling ◽  
Wave Dynamics ◽  
Systematic Exploration ◽  
Voltage Gradients

AbstractThe development of new approaches to control cardiac arrhythmias requires a deep understanding of spiral wave dynamics. Optogenetics offers new possibilities for this. Preliminary experiments show that sub-threshold illumination affects electrical wave propagation in the mouse heart. However, a systematic exploration of these effects is technically challenging. Here, we use state-of-the-art computer models to study the dynamic control of spiral waves in a two-dimensional model of the adult mouse ventricle, using stationary and non-stationary patterns of sub-threshold illumination. Our results indicate a light intensity-dependent increase in cellular resting membrane potentials, which together with diffusive cell-cell coupling leads to the development of spatial voltage gradients over differently illuminated areas. A spiral wave drifts along the positive gradient. These gradients can be strategically applied to ensure drift-induced termination of a spiral wave, both in optogenetics and in conventional methods of electrical defibrillation.

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