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OCTOBER 2001:    Contents

Clin. Cardiol. 24, 682–688 (2001)

Magnetocardiographic Mapping of QRS Fragmentation in Patients with a History of Malignant Tachyarrhythmias

P. Gödde, M.D., R. Agrawal, M.D., H.-P. Müller, Ph.D., K. Czerski, Ph.D., P. Endt, Ph.D.,* U. Steinhoff, M.Sc.,* M. Oeff, M.D., H.-P. Schultheiss, M.D., S. Behrens, M.D.

University Clinic Benjamin Franklin, Free Berlin University, 2nd Medical Clinic, Department of Cardiology and Pulmonary Disease; *Federal Institute for Physics and Technology, Berlin, Germany

Summary

Background: The identification of patients at increased risk for ventricular tachycardia or ventricular fibrillation (VT/VF) and sudden cardiac death has consequences for therapeutic options and thus may reduce mortality in patients with coronary artery disease (CAD).

Hypothesis: We hypothesized that the intra-QRS fragmentation in magnetocardiographic recordings is increased in patients with CAD and with a history of VT/VF.

Methods: Multichannel magnetocardiography (MCG) was carried out in 34 healthy controls, 42 patients with CAD without a history of VT/VF, and 43 patients with CAD and with a history of VT/VF. The intra-QRS fragmentation was quantified by a new fragmentation score. Its spatial distribution was investigated using two-dimensional (2-D) contour maps according to the sensor position of the 49-channel magnetogradiometer.

Results: Patients with CAD and with a history of VT/VF had significantly increased QRS fragmentation compared with patients with CAD without VT/VF or controls (72.9 ± 37.5, 48.5 ± 14.3, and 42.5 ± 7.8, respectively; p<0.05). The area of high fragmentation in 2-D contour maps was twice as large in patients with than in those without a history of VT/VF (represented by the number of MCG channels with high fragmentation: 26.3 ± 15.5 vs. 12.4 ± 9.9, p<0.0001). Patients prone to VT/VF could be identified with a sensitivity of 64% and a specificity of 90%.

Conclusion: In patients with CAD and with a history of VT/VF, intra-QRS fragmentation is increased and the area of high fragmentation in 2-D contour maps is enlarged. These findings may be helpful in identifying patients with CAD at risk for malignant tachyarrhythmias.

Key words: magnetocardiography, mapping, ventricular arrhythmias, coronary artery disease, arrhythmogenic substrate

This study was supported by a grant of the Bundesministerium für Bildung und Forschung (13N6931/1).

Address for reprints:
Steffen Behrens, M.D.
Universitätsklinikum Benjamin Franklin
Freie Universität Berlin
Medizinische Klinik II
Abteilung für Kardiologie und Pulmologie
Hindenburgdamm 30
12200 Berlin, Germany

Received: June 13, 2000
Accepted with revision: January 3, 2001


©1997-2002 Foundation for Advances in Medicine and Science