Detecting activations in unipolar epicardial electrograms recorded during ventricular fibrillation

Author

Blanchard, Susan M. ; Tohmaz, Abdul S. ; Cervino, Donald J. ; Pool, Tamara S. ; Clark, Bryan P. ; Johnson, Eric E. ; Ideker, Raymond E.

Author_Institution

North Carolina State Univ., Raleigh, NC, USA

fYear

1995

fDate

10-13 Sept. 1995

Firstpage

793

Lastpage

796

Abstract

Detecting activations (ACTs) from unipolar electrograms (UEGs) is difficult during ventricular fibrillation (VF) due to the superposition of distant activity from multiple wavefronts. Epicardial UEGs were recorded during the first 2 s of VF from an 11/spl times/11 array of Ag-AgCl electrodes spaced 280 /spl mu/m apart on the LV apex of 5 open-chest pigs. The Rule-Based Method (RBM) used maximum negative derivatives (DERs) located at least 56 ms apart to identify RBM-ACTs while the Transmembrane Current Method (TCM) used electrograms recorded from sites with 4 orthogonal neighbors to estimate I/sub m/ at the center site. Biphasic deflections of I/sub m/ that occurred at the same time as negative DERs were used to indicate TCM-ACTs. All RBM-ACTs with DER /spl les/-1.5 mV/ms (5119 of the 5650 investigated) were assumed to represent true activations. TCM-ACTs confirmed activation for 251 RBM-ACTs with -1.5\n\n\t\t

Keywords

electrocardiography; medical signal processing; 2 s; 280 mum; 56 ms; Ag-AgCl; Ag-AgCl electrodes array; activations detection; biphasic deflections; distant activity superposition; electrotonic activity; multiple wavefronts; open-chest pigs; orthogonal neighbors; transmembrane current method; unipolar epicardial electrograms; ventricular fibrillation; Animals; Cardiac tissue; Density estimation robust algorithm; Electrodes; Fibrillation; Filters; Heart; Rhythm; Steel; Wire;

fLanguage

English

Publisher

ieee

Conference_Titel

Computers in Cardiology 1995

Conference_Location

Vienna, Austria

Print_ISBN

0-7803-3053-6

Type

conf

DOI

10.1109/CIC.1995.482784

Filename

482784