High-Resolution Magnetocardiographic Mapping of Pre-Excitation in Wolff-Parkinson-White Syndrome

Abstract

We have studied 10 Wolff-Parkinson-White (WPW) syndrome patients using high-resolution magnetocardiographic (HR-MCG) mapping, standard 12-lead ECG and invasive electrophysiologic study (EPS). The ventricular pre-excitation caused by abnormal conduction via an accessory pathway (AP), seen as a so-called delta-wave prior to the QRS complex, was characterized by studying the morphology of the QRS and the delta-wave in the measured ECG and MCG signals. For all patients, EPS was performed to determine the conduction properties and the location of the AP. The site of the pre-excitation was also localized using the HR-MCG mapping and the results were compared to the invasive results. For a surgical operation or catheter ablation therapy, the site of the AP should be determined with a reasonable accuracy. Noninvasive methods, such as the HR-MCG, would be helpful in minimizing the duration and discomfort of invasive catheter mapping and in some cases could even replace it. Studies of WPW patients have been previously reported by Erné et al. (1985) and first simultaneous catheter and MCG mapping was done by Fenici et al. (1985).