DocumentCode :
1463214
Title :
A simultaneous multichannel monophasic action potential electrode array for in vivo epicardial repolarization mapping
Author :
Sahakian, Alan V. ; Peterson, Ming-Shing Lee ; Shkurovich, Sergio ; Hamer, Mark ; Votapka, Timothy ; Ji, Tongyou ; Swiryn, Steven
Author_Institution :
Dept. of Electr. & Comput. Eng., Northwestern Univ., Evanston, IL, USA
Volume :
48
Issue :
3
fYear :
2001
fDate :
3/1/2001 12:00:00 AM
Firstpage :
345
Lastpage :
353
Abstract :
While the recording of extracellular monophasic action potentials (MAPs) from single epicardial or endocardial sites has been performed for over a century, the authors are unaware of any previous successful attempt to record MAPs simultaneously from a large number of sites in vivo. They report here the design and validation of an array of MAP electrodes which records both depolarization and repolarization simultaneously at up to 16 epicardial sites in a square array on the heart in vivo. The array consists of 16 sintered Ag-AgCl electrodes mounted in a common housing with individual suspensions allowing each electrode to exert a controlled pressure on the epicardial surface. The electrodes are arranged in a square array, with each quadrant of four having an additional recessed sintered Ag-AgCl reference electrode at its center. A saline-soaked sponge establishes ionic contact between the reference electrodes and the tissue. The array was tested on six anesthetized open-chested pigs. Simultaneous diagnostic-quality MAP recordings were obtained from up to 13 out of 16 ventricular sites. Ventricular MAPs had amplitudes of 10-40 mV with uniform morphologies and stable baselines for up to 30 min, MAP duration at 90% repolarization was measured and shown to vary as expected with cycle length during sustained pacing. The relationship between MAP duration and effective refractory period was also confirmed. The ability of the array to detect local differences in repolarization was tested in two ways. Placement of the array straddling the atrioventricular (AV) junction yielded simultaneous atrial or ventricular recordings at corresponding sites during 1:1 and 2:1 AV conduction. Localized ischemia via constriction of a coronary artery branch resulted in shortening of the repolarization phase at the ischemic, but not the nonischemic, sites. In conclusion, these results indicate that the simultaneous multichannel MAP electrode array is a viable method for in vivo epicardial repo- - larization mapping. The array has the potential to be expanded to increase the number of sites and spatial resolution.
Keywords :
biomedical electrodes; electrocardiography; 10 to 40 mV; 30 min; Ag-AgCl; anesthetized open-chested pigs; coronary artery branch constriction; diagnostic-quality MAP recordings; extracellular monophasic action potentials recording; in vivo epicardial repolarization mapping; ionic contact; ischemic sites; nonischemic sites; recessed sintered Ag-AgCl reference electrode; saline-soaked sponge; simultaneous multichannel monophasic action potential electrode array; spatial resolution; Electrodes; Extracellular; Heart; In vivo; Length measurement; Pressure control; Simultaneous localization and mapping; Surface morphology; Suspensions; Testing; Action Potentials; Animals; Body Surface Potential Mapping; Electrodes; Equipment Design; Female; Heart Block; Male; Myocardial Ischemia; Pericardium; Swine;
fLanguage :
English
Journal_Title :
Biomedical Engineering, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9294
Type :
jour
DOI :
10.1109/10.914798
Filename :
914798
Link To Document :
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