Comparison of Body Surface and Intracardiac ECG Recordings in Patients with Atrial Fibrillation during Electrophysiological Studies

Abstract

Atrial fibrillation (AF) dominant frequency (DF) is thought to reflect the degree of organisation of underlying atrial activity (AA). Our aim was to evaluate the relationship between the DFs from the body surface electrocardiogram (ECG) and intracardiac electrogram (EGM). Surface recordings of the ECG with 64 electrodes were obtained from 12 patients during AF ablation procedures. After subtracting ventricular activity (QRST), DF was obtained from spectral analysis of the channel exhibiting the largest AF component. Intracardiac recordings from the coronary sinus (CS) were obtained simultaneously, the DF was extracted from the channel closest to the left atrium. 24 recordings of 2 minute duration were analysed. Mean (SD) DF of the body surface ECG recording was 6.09 (0.87) Hz, and for intracardiac recording was 5.78 (0.84). Although in individual subjects there were differences in DF between the surface and intracardiac recordings up to 1.6 Hz, overall the difference was only 0.31 (0.64) Hz and was not significant.