Name: high-resolution endocardial and epicardial optical mapping in a sheep model of stretch-induced atrial fibrillation
Uploaded: 2011-07-29T14:00:00
Description: Watch this Scientific Journal Video about High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation at JoVE.com

Supported in part by NHLBI Grants P01-HL039707 and P01-HL087226 and the Leducq Foundation (J.J. and O.B.), by a Spanish Society of Cardiology Fellowship, Fundaci&oacute;n Pedro Barri&eacute; de la Maza and Fundaci&oacute;n Alfonso Mart&iacute;n Escudero (D.F.R.), by F&eacute;d&eacute;ration Fran&ccedil;aise de Cardiologie (R.P.M.), by a Heart Rhythm Society fellowship Award, The Fellowship of Japan Heart Foundation/The Japanese Society of Electrocardiology (M.Y.).

1. Heart removal and Langendorff perfusion
 Sheep weighing 35-40 Kg are anesthetized using 4-6 mg/Kg propofol and 60-100 mg/Kg of sodium pentobarbital. Hearts are removed via thoracotomy and connected to a Langendorff-perfusion system with circulating oxygenated (95% O2, 5% CO2) Tyrode's solution at a constant flow rate of 240-270 ml/min, pH 7.4 and 35.5-37.5 &deg;C. The Tyrode's composition (in mM) is: NaCl 130, KCl 4.0, MgCl2 1, CaCl2 1.8, NaHCO3 24, NaH2PO4 1.2, Glucose 5.6, and Albumin 0.04 ...

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	<li>Kannel, W. B., Wolf, P. A., Benjamin, E. J., Levy, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence,+incidence,+prognosis,+and+predisposing+conditions+for+atrial+fibrillation:+population-based+estimates.">Prevalence, incidence, prognosis, and predisposing conditions for atrial fibrillation: population-based estimates.</a> Am J Cardiol. 82, (1998).</li><li>Wolf, P. A., Abbott, R. D., Kannel, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atrial+fibrillation+as+an+independent+risk+factor+for+stroke:+the+Framingham+Study.">Atrial fibrillation as an independent risk factor for stroke: the Framingham Study.</a> Stroke. 22, 983-988 (1991).</li><li>Miyasaka, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Secular+trends+in+incidence+of+atrial+fibrillation+in+Olmsted+County,+Minnesota,+1980+to+2000,+and+implications+on+the+projections+for+future+prevalence.">Secular trends in incidence of atrial fibrillation in Olmsted County, Minnesota, 1980 to 2000, and implications on the projections for future prevalence.</a> Circulation. 114, 119-125 (1980).</li><li>Ravelli, F., Allessie, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+atrial+dilatation+on+refractory+period+and+vulnerability+to+atrial+fibrillation+in+the+isolated+Langendorff-perfused+rabbit+heart.">Effects of atrial dilatation on refractory period and vulnerability to atrial fibrillation in the isolated Langendorff-perfused rabbit heart.</a> Circulation. 96, 1686-1695 (1997).</li><li>Gray, R. A., Pertsov, A. M., Jalife, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+and+temporal+organization+during+cardiac+fibrillation.">Spatial and temporal organization during cardiac fibrillation.</a> Nature. 392, 75-78 (1998).</li><li>Gray, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+cardiac+fibrillation.">Mechanisms of cardiac fibrillation.</a> Science. 270, 1222-1225 (1995).</li><li>Samie, F. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rectification+of+the+background+potassium+current:+a+determinant+of+rotor+dynamics+in+ventricular+fibrillation.">Rectification of the background potassium current: a determinant of rotor dynamics in ventricular fibrillation.</a> Circ Res. 89, 1216-1223 (2001).</li><li>Kalifa, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intra-atrial+pressure+increases+rate+and+organization+of+waves+emanating+from+the+superior+pulmonary+veins+during+atrial+fibrillation.">Intra-atrial pressure increases rate and organization of waves emanating from the superior pulmonary veins during atrial fibrillation.</a> Circulation. 108, 668-671 (2003).</li><li>Mandapati, R., Skanes, A., Chen, J., Berenfeld, O., Jalife, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stable+microreentrant+sources+as+a+mechanism+of+atrial+fibrillation+in+the+isolated+sheep+heart.">Stable microreentrant sources as a mechanism of atrial fibrillation in the isolated sheep heart.</a> Circulation. 101, 194-199 (2000).</li><li>Yamazaki, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+stretch-induced+atrial+fibrillation+in+the+presence+and+the+absence+of+adrenocholinergic+stimulation:+interplay+between+rotors+and+focal+discharges.">Mechanisms of stretch-induced atrial fibrillation in the presence and the absence of adrenocholinergic stimulation: interplay between rotors and focal discharges.</a> Heart Rhythm. 6, 1009-1017 (2009).</li><li>Rama, D. F., Jalife, J., Antzelevitch, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+Underlying+Atrial+Fibrillation.">Mechanisms Underlying Atrial Fibrillation.</a> Basic Science for Clinical Electrophysiologist. 3, 141-156 (2011).</li><li>Berenfeld, O., Zaitsev, A. V., Mironov, S. F., Pertsov, A. M., Jalife, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequency-dependent+breakdown+of+wave+propagation+into+fibrillatory+conduction+across+the+pectinate+muscle+network+in+the+isolated+sheep+right+atrium.">Frequency-dependent breakdown of wave propagation into fibrillatory conduction across the pectinate muscle network in the isolated sheep right atrium.</a> Circ Res. 90, 1173-1180 (2002).</li><li>Haissaguerre, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spontaneous+initiation+of+atrial+fibrillation+by+ectopic+beats+originating+in+the+pulmonary+veins.">Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins.</a> N Engl J Med. 339, 659-666 (1998).</li><li>Warren, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blockade+of+the+inward+rectifying+potassium+current+terminates+ventricular+fibrillation+in+the+guinea+pig+heart.">Blockade of the inward rectifying potassium current terminates ventricular fibrillation in the guinea pig heart.</a> J Cardiovasc Electrophysiol. 14, 621-631 (2003).</li><li>Claerbout, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fundamentals of Geophysical Data Processing. , (1976).</li><li>Atienza, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+dominant+frequency+mapping+and+ablation+of+dominant+frequency+sites+in+atrial+fibrillation+with+left-to-right+frequency+gradients+predicts+long-term+maintenance+of+sinus+rhythm.">Real-time dominant frequency mapping and ablation of dominant frequency sites in atrial fibrillation with left-to-right frequency gradients predicts long-term maintenance of sinus rhythm.</a> Heart Rhythm. 6, 33-40 (2009).</li></ol>

The characteristics of acute stretch-induced AF in the isolated sheep heart resemble some of the properties of human paroxysmal AF. An acute increase in intra-atrial pressure in the sheep heart allows the maintenance of AF for long periods of time, similar to a higher risk of AF observed in patients with atrial dilatation.1 The presence of left-to-right DF gradients in the sheep atria is also similar to those registered in human electrophysiological studies.16 Therefore, understanding the mechanism ...

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Material Name
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Company		
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Catalogue Number
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Euthanasia
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Heparin
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Sigma
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H3393
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Propofol
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Abbott
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5206-04-03
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Pentobarbital
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Lundbeck Inc
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NDC 67386-501-55
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Introducer 18 Gauge
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Terumo
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SS*FF1832
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Cuffed endotracheal tube (9 mm)
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DRE Veterinary
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Fiber Optic Laryngoscope Case
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Fiber Optic Blade
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Operating Scissors
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DRE Veterinary
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Scalpel Handle #3 Solid 4&quot;
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Roboz Surgical Instrument Co., Inc.
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RS-9843
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Sterile Scalpel Blades
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Roboz Surgical Instrument Co., Inc.
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RS-9801-10
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Ventilation bag
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Westmed
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562013
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Sims Scissors Curved Sharp/Blunt
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Roboz Surgical Instrument Co., Inc.
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RS-7035
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Tissue Forceps (&times;2)
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DRE Veterinary
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#1895
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KANTROWITZ Thoracic Forceps, 11&quot;&nbsp;
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Biomedical Research Instruments, Inc.
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34-1980
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Finochietto Large Chest Spreader
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Kapp Surgical Instrument Inc.
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KS-7301
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Thoracotomy shears
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Rostfrei Solingen
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Plastic tray
</td>
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Nalgene
</td>
<td>
Fischer
</td>
</tr>
<tr>
<td>
Optical mapping
</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
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Bonn Scissors (&times;2)
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Roboz Surgical Instrument Co., Inc
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RS-5840SC
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Surgical silk
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Fischer
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50-900-04214
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Micro Dissecting Forceps
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<td>
Roboz Surgical Instrument Co., Inc
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RS-5130
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Tetrapolar electrode catheters (Torq) (&times;4)
</td>
<td>
Medtronic Inc.
</td>
<td>
05580SP
</td>
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<tr>
<td>
Digital sensor. Biopac Systems transducer
</td>
<td>
Biopac Systems, Inc.
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RX104A
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Biopac Systems amplifier
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Biopac Systems, Inc.
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DA-100C
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Di-4-ANEPPS
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Sigma-Aldrich, St.
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D8604-5mg
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Blebbistatin
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Enzo Life Science International, INC.
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BML-E1315-0025
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LittleJoe CCD video camera(&times;2)
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SciMeasure Analytical Systems, Inc.
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Dual-channel rigid borescope
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Everest VIT, Inc.
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R10-25-0-90
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Perfusion pumps (&times;2)
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<td>
Cole Parmer
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GK-77920-30
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Temperature probe
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Cole Parmer
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R-08491-02
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pH meter
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Fischer
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Digital temperature gauge
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Cole Parmer
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Oxygenator filters
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Sorin
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05318
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Silicon perfusion tubes (L/S 15)
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MasterFlex
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96410-15
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Laser light guides (&times;6)
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Oriel Corporation
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Liquid light-guide (0.2 in core)
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Newport Corporation
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Laser generator (1 watt) 

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Shanghai Dream Lsaer Tecchnology
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Laser generator (5 watt)
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Spectra Physics Lasers
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MILL 5sJ
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</table>

high-resolution endocardial and epicardial optical mapping in a sheep model of stretch-induced atrial fibrillation

Atrial fibrillation (AF) is a complex cardiac arrhythmia with high morbidity and mortality.1,2 It is the most common sustained cardiac rhythm disturbance seen in clinical practice and its prevalence is expected to increase in the coming years.3 Increased intra-atrial pressure and dilatation have been long recognized to lead to AF,1,4 which highlights the relevance of using animal models and stretch to study AF dynamics. Understanding the mechanisms underlying AF requires visualization of the cardiac electrical waves with high spatial and temporal resolution. While high-temporal resolution can be achieved by conventional electrical mapping traditionally used in human electrophysiological studies, the small number of intra-atrial electrodes that can be used simultaneously limits the spatial resolution and precludes any detailed tracking of the electrical waves during the arrhythmia. The introduction of optical mapping in the early 90's enabled wide-field characterization of fibrillatory activity together with sub-millimeter spatial resolution in animal models5,6 and led to the identification of rapidly spinning electrical wave patterns (rotors) as the sources of the fibrillatory activity that may occur in the ventricles or the atria.7-9 Using combined time- and frequency-domain analyses of optical mapping it is possible to demonstrate discrete sites of high frequency periodic activity during AF, along with frequency gradients between left and right atrium. The region with fastest rotors activates at the highest frequency and drives the overall arrhythmia.10,11 The waves emanating from such rotor interact with either functional or anatomic obstacles in their path, resulting in the phenomenon of fibrillatory conduction.12 Mapping the endocardial surface of the posterior left atrium (PLA) allows the tracking of AF wave dynamics in the region with the highest rotor frequency. Importantly, the PLA is the region where intracavitary catheter-based ablative procedures are most successful terminating AF in patients,13 which underscores the relevance of studying AF dynamics from the interior of the left atrium. Here we describe a sheep model of acute stretch-induced AF, which resembles some of the characteristics of human paroxysmal AF. Epicardial mapping on the left atrium is complemented with endocardial mapping of the PLA using a dual-channel rigid borescope c-mounted to a CCD camera, which represents the most direct approach to visualize the patterns of activation in the most relevant region for AF maintenance.

Watch this Scientific Journal Video about High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation at JoVE.com

High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation.

 Atrial fibrillation (AF) is a complex cardiac arrhythmia with high morbidity and mortality.1,2 It is the most common sustained cardiac rhythm disturbance ...

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