Fragmented endocardial electrical activity in patients with ventricular tachycardia: A new guide to surgical therapy

1984 ◽  
Vol 107 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Isaac Wiener ◽  
Bruce Mindich ◽  
Roberta Pitchon
Keyword(s):  
Ventricular Tachycardia ◽  
Electrical Activity ◽  
Surgical Therapy

Transient entrainment of ventricular tachycardia with continuous local electrical activity

1987 ◽  
Vol 114 (1) ◽  
pp. 182-184 ◽  
Author(s):  
Yoshifusa Aizawa ◽  
Hirotaka Oda ◽  
Masahito Satoh ◽  
Minoru Murata ◽  
Akira Shibata ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Electrical Activity

scholarly journals The limitations of epicardial mapping as a guide to the surgical therapy of ventricular tachycardia.

Circulation ◽  
1978 ◽  
Vol 57 (4) ◽  
pp. 666-670 ◽  
Author(s):  
S R Spielman ◽  
E L Michelson ◽  
L N Horowitz ◽  
J F Spear ◽  
E N Moore
Keyword(s):  
Ventricular Tachycardia ◽  
Surgical Therapy ◽  
Epicardial Mapping

scholarly journals Continuous local electrical activity. A mechanism of recurrent ventricular tachycardia.

Circulation ◽  
1978 ◽  
Vol 57 (4) ◽  
pp. 659-665 ◽  
Author(s):  
M E Josephson ◽  
L N Horowitz ◽  
A Farshidi
Keyword(s):  
Ventricular Tachycardia ◽  
Electrical Activity

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.

scholarly journals A Software Architecture to Mimic a Ventricular Tachycardia in Intact Murine Hearts by Means of an All-Optical Platform

2019 ◽  
Vol 2 (1) ◽  
pp. 7 ◽  
Author(s):  
Francesco Giardini ◽  
Valentina Biasci ◽  
Marina Scardigli ◽  
Francesco S. Pavone ◽  
Gil Bub ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Electrical Activity ◽  
Real Time ◽  
Temporal Resolution ◽  
Technical Note ◽  
High Temporal Resolution ◽  
Excitable Cells ◽  
New Approach ◽  
Cardiac Electrical Activity ◽  
All Optical

Optogenetics is an emerging method that uses light to manipulate electrical activity in excitable cells exploiting the interaction between light and light-sensitive depolarizing ion channels, such as channelrhodopsin-2 (ChR2). Initially used in the neuroscience, it has been adopted in cardiac research where the expression of ChR2 in cardiac preparations allows optical pacing, resynchronization and defibrillation. Recently, optogenetics has been leveraged to manipulate cardiac electrical activity in the intact heart in real-time. This new approach was applied to simulate a re-entrant circuit across the ventricle. In this technical note, we describe the development and the implementation of a new software package for real-time optogenetic intervention. The package consists of a single LabVIEW program that simultaneously captures images at very high frame rates and delivers precisely timed optogenetic stimuli based on the content of the images. The software implementation guarantees closed-loop optical manipulation at high temporal resolution by processing the raw data in workstation memory. We demonstrate that this strategy allows the simulation of a ventricular tachycardia with high stability and with a negligible loss of data with a temporal resolution of up to 1 ms.

Effect of coronary occlusion on arrhythmias and conduction in the ovine heart

1983 ◽  
Vol 245 (1) ◽  
pp. H82-H89 ◽  
Author(s):  
D. E. Euler ◽  
J. F. Spear ◽  
E. N. Moore
Keyword(s):  
Ventricular Tachycardia ◽  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Electrical Activity ◽  
Coronary Occlusion ◽  
Circumflex Coronary Artery ◽  
Pentobarbital Sodium ◽  
Normal Zone ◽  
Ventricular Tachycardia And Fibrillation ◽  
Observation Period

The proximal left circumflex coronary artery was occluded for 1 h in 16 open-chest sheep anesthetized with pentobarbital sodium. Epicardial conduction was monitored at three or four sites within the ischemic zone and one site in the normal zone. Eight of the sheep developed ventricular fibrillation within the first 15 min of occlusion; the remaining sheep survived the 1-h observation period. In the sheep that developed spontaneous ventricular fibrillation, the circumflex perfused a significantly greater amount of the left ventricle (44 +/- 3 vs. 39 +/- 3%; P = 0.008). The occurrence of spontaneous ventricular fibrillation was invariably preceded by a period of sustained (0.5-4 min) ventricular tachycardia. Six of the surviving sheep developed episodes of sustained (2-10 min) tachycardia that were self-terminating. The ischemic zone electrograms showed continuous fractionated electrical activity during both self-terminating tachycardias and tachycardias ending in fibrillation. The continuous epicardial electrical activity did not appear to cause the tachycardias but rather occurred as a result of the tachycardias. The genesis of ventricular tachycardia and fibrillation in this model may involve mechanisms different from ischemia-induced ventricular tachycardia and fibrillation in canine and porcine hearts.

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