First 36-channel System for Clinical Magnetocardiography in Unshielded Hospital Laboratory for Cardiac Electrophysiology.

Abstract. Multichannel Magnetocardiography (MMCG) is a contactless method, which provides non-invasive three-dimensional imaging of cardiac electrogenetic phenomena. However a multichannel system reliable in an unshielded hospital environment was needed, to bring it into clinical practice. We have recently installed the first 36-channel system for MMCG operating in an unshielded EP catheterization laboratory, and validated its accuracy for cardiac source localization. In this paper an overview is given of system performance during daily clinical use. The 36-channel recording lasts typically 90 seconds. Post-processing takes 2 minutes. A standard bicycle-ergometer protocol has been used for exercise MMCG. Equivalent current dipole (ECD), Effective Magnetic Dipole (EMD) and distributed currents (DC) models are used for 3D source localization and multimodal imaging. Since November 2002, 256 patients, affected by different kinds of cardiac problems, were studied at least twice to test for reproducibility. The new system is fully reliable and provides 3D source localization as well as quantitative estimate of electrophysiological parameters, with accuracy good enough for clinical use.