scholarly journals Electrical Alternans by ECG Finding

2020 ◽  
Author(s):  
Keyword(s):  
Electrical Alternans

scholarly journals Electrical alternans and its resolution in an adult with a large pericardial effusion

2004 ◽  
Vol 27 (12) ◽  
pp. 701-701
Author(s):  
Richard A. Kerensky ◽  
Jonica Calkins ◽  
Ezra Amsterdam
Keyword(s):  
Pericardial Effusion ◽  
Large Pericardial Effusion ◽  
Electrical Alternans

Electrical Alternans due to Cardiac Tamponade

Herz ◽  
2005 ◽  
Vol 30 (2) ◽  
pp. 151-152 ◽  
Author(s):  
Philipp Kahlert ◽  
Marc-Alexander Katz ◽  
Thomas Buck ◽  
Raimund Erbel
Keyword(s):  
Cardiac Tamponade ◽  
Electrical Alternans

scholarly journals Mechanism of QRS electrical alternans.

Heart ◽  
1997 ◽  
Vol 77 (2) ◽  
pp. 180-182 ◽  
Author(s):  
B. Brembilla-Perrot ◽  
H. Lucron ◽  
F. Schwalm ◽  
A. Haouzi
Keyword(s):  
Electrical Alternans

Rhythm effects on contractility of the beating isovolumic left ventricle

1960 ◽  
Vol 199 (6) ◽  
pp. 1115-1120 ◽  
Author(s):  
B. Lendrum ◽  
H. Feinberg ◽  
E. Boyd ◽  
L. N. Katz
Keyword(s):  
Heart Rate ◽  
Left Ventricle ◽  
Systolic Pressure ◽  
Ventricular Volume ◽  
Contractile Force ◽  
Postextrasystolic Potentiation ◽  
Pressure Development ◽  
Induced Changes ◽  
Electrical Alternans

Variation in contractile force of the isovolumic contracting left ventricle of the dog was studied in open-chested in situ hearts. The electrocardiogram and intraventricular pressures were recorded at various heart volumes. Spontaneous changes in heart rate and rhythm occurred at all volumes. Isovolumic systolic pressure development (contractile force) varied with rate and rhythm. Contractile force increased with heart rate (treppe) regardless of pacemaker origin. When a premature beat was followed by a compensatory pause, the premature beat showed a decrease and the next beat an increase in contractile force (postextrasystolic potentiation). The magnitude of the changes varied directly with the prematurity of the beat. Mechanical alternans was observed with electrical alternans, despite the absence of significant volume change. Rate-induced changes, postextrasystolic potentiation and mechanical alternans were additive when they occurred simultaneously. For practical purposes, ventricular volume (filling), hence muscle fiber length, remained constant during these rate and rhythm change, therefore could not affect the strength of contraction. Contractile force changes directly attributable to rate and rhythm changes do, therefore, occur in the intact mammalian heart.

scholarly journals Methodology for detection of paroxysmal atrial fibrillation based on P-Wave, HRV and QR electrical alternans features

2020 ◽  
Vol 10 (4) ◽  
pp. 4023
Author(s):  
Henry Castro ◽  
Juan David Garcia-Racines ◽  
Alvaro Bernal-Noreña
Keyword(s):  
Neural Network ◽  
Atrial Fibrillation ◽  
Paroxysmal Atrial Fibrillation ◽  
P Wave ◽  
Computational Techniques ◽  
K Nearest Neighbors ◽  
Ecg Signals ◽  
Complex Process ◽  
Artificial Neural Network Ann ◽  
Electrical Alternans

The detection of Paroxysmal Atrial Fibrillation (PAF) is a fairly complex process performed manually by cardiologists or electrophysiologists by reading an electrocardiogram (ECG). Currently, computational techniques for automatic detection based on fast Fourier transform (FFT), Bayes optimal classifier (BOC), k-nearest neighbors (K-NNs), and artificial neural network (ANN) have been proposed. In this study, six features were obtained based on the morphology of the P-Wave, the QRS complex and the heart rate variability (HRV) of the ECG. The performance of this methodology was validated using clinical ECG signals from the Physionet arrhythmia database MIT-BIH. A feedforward neural network was used to detect the presence of PAF reaching a general accuracy of 97.4%. The results obtained show that the inclusion of the information of the P-Wave, HRV and QR Electrical alternans increases the accuracy to identify the PAF event compared to other works that use the information of only one or at most two of them.

Abstract 71: Model of Induced Ventricular Tachycardia and Cardiac Electrophysiological Mapping

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Ike Chinyere ◽  
Kyle Weigand ◽  
Talal Moukabary ◽  
Russell Witte ◽  
Jordan Lancaster ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
User Interface ◽  
Electrical Activity ◽  
Intact Animal ◽  
Pulseless Electrical Activity ◽  
Border Zone ◽  
Coronary Artery Ligation ◽  
Computer User ◽  
Arrhythmogenic Potential ◽  
Electrical Alternans

Introduction: We have developed a computer user interface able to provide prescribed programmed electrical stimulation (PES) to induce sustained-ventricular tachycardia (VT) in rats with chronic heart failure (CHF). We propose this program to examine the cardiac electrophysiology (EP) properties and arrhythmogenic potential in varying disease models and as a method of evaluating drug safety in an intact animal. Methods: Using custom MATLAB software developed in our laboratory, we performed monophasic action potential (MAP) recordings and initiated protocols to induce sustained-VT through right ventricular epicardium PES outputs. Studies were performed in adult male Sprague-Dawley rats (N=22) six weeks after left coronary artery ligation under anesthesia and open chest. Results: CHF was verified by standard hemodynamic and echocardiographic parameters as is standard in our laboratory. In the CHF group, 71% (10/14) of the rats exhibited sustained-VT in response to PES versus 0% (0/8) of Sham rats. MAP recordings taken prior-to and during VT induction provided examples of localized activity for arrhythmia mechanisms such as delayed afterdepolarizations. Mechanical alternans, electrical alternans, intermittent pulse generations, and pulseless electrical activity were all observed in this model. EP data analysis showed a decreased (p<0.05) electrogram amplitude in border and infarct zones (Healthy (H): 8.7 ±2.1 mV, Border: 5.3±1.6 mV, Infarct (I): 2.3±1.2 mV), a similar trend for MAP amplitudes, and an increased (p<0.05) repolarization heterogeneity in the border zone (H: 8.1±1.5 ms, B: 20.2±3.1 ms). Conclusions: We have developed a custom computer user interface capable of performing clinically relevant in-vivo EP studies in rats with CHF. This rat model reproduces common clinical prognosis factors such as mechanical alternans, electrical alternans, and pulseless electrical activity. These EP studies demonstrate this program’s ability to test the arrhythmogenic potential of pharmaceutic agents, biologics, and implantables in an intact animal model before clinical advancement. We introduce this program to study an animal model’s EP characteristics before, during, and after treatments for CHF, and potentially other disease states.

Regional electromechanical alternans in anesthetized pig hearts: modulation by mechanoelectric feedback

1994 ◽  
Vol 267 (5) ◽  
pp. H1726-H1735 ◽  
Author(s):  
C. F. Murphy ◽  
M. J. Lab ◽  
S. M. Horner ◽  
D. J. Dick ◽  
F. G. Harrison
Keyword(s):  
Left Ventricle ◽  
Action Potential ◽  
Monophasic Action Potential ◽  
Mechanical Activity ◽  
Strain Gauges ◽  
Atrial Pacing ◽  
Mechanoelectric Feedback ◽  
Pulsus Alternans ◽  
Electrical Alternans ◽  
Intact Heart

Electrical and mechanical alternans have often been found to coexist. However, the factors controlling their interdependence are not known. In this study we measure regional electrical and mechanical activity during mechanical alternans to investigate this relationship. Mechanical alternans was induced by rapid atrial pacing in 18 anesthetized, open-chest pigs. Regional segmental contraction and monophasic action potential were measured in three areas of left ventricle using epicardial tripodal strain gauges and suction electrodes. Electrical alternans always accompanied pulsus alternans. The phase of electrical alternans was not related to any measure of regional mechanical activity but did show a constant discordant relation to peak ventricular pressure. This suggested that mechanically dependent changes in action potential duration (mechanoelectric feedback) may be important in modulation electrical alternans. In support of this, pulsus alternans simulated by clamping the proximal aorta on alternate beats was associated with electrical alternans comparable to that produced with rapid atrial pacing. Mechanoelectric feedback modulates regional electrophysiology in the intact heart and may be important in the generation of electrical alternans.

scholarly journals Mechanisms linking electrical alternans and clinical ventricular arrhythmia in human heart failure

Heart Rhythm ◽  
2016 ◽  
Vol 13 (9) ◽  
pp. 1922-1931 ◽  
Author(s):  
J.D. Bayer ◽  
G.G. Lalani ◽  
E.J. Vigmond ◽  
S.M. Narayan ◽  
N.A. Trayanova
Keyword(s):  
Heart Failure ◽  
Ventricular Arrhythmia ◽  
Human Heart ◽  
Human Heart Failure ◽  
Electrical Alternans

Electrical alternans of giant U waves with multiple electrolyte deficits

1984 ◽  
Vol 54 (7) ◽  
pp. 920-921 ◽  
Author(s):  
Zvi Shimoni ◽  
Edith Flatau ◽  
Dan Schiller ◽  
Eitan Barzilay ◽  
David Kohn
Keyword(s):  
Electrical Alternans
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