Magnetocardiographic electroanatomical imaging for pre-interventional evaluation of arrhythmogenic substrates

Catheter ablation has significantly changed the diagnostic approach and the treatment of cardiac arrhythmias. Being the appropriate localization of the arrhythmogenic target a key-point for effective ablation, new technologies have been recently developed, for three-dimensional (3D) electroanatomical imaging during ablation procedures. However all of them are invasive and cannot be used for preoperative assessment and localization of arrhythmogenic substrates. Magnetocardiographic mapping (MCG) on the contrary is a feasible method, which provide 3D electroanatomical imaging of cardiac sources non-invasively, therefore it can be repeated on ambulatory patients, to define the characteristics of the arrhythmogenic substrate before intervention. MCG detection of electrophysiologic (EP) abnormalities and 3D electroanatomical imaging of arrhythmogenic substrates can be enhanced by simultaneous EP study with amagnetic trans-esophageal atrial pacing. Alternatively minimally invasive, single-catheter multiple monophasic action potential recordings (Multi-MAP) can be aimed at the arrhythmogenic targets identified by MCG. The MCG-guided Multi-MAP EP study is also useful for direct validation of MCG estimate of atrial and ventricular de-repolarization by comparison with simultaneous MAP recordings in sinus rhythm and under pacing. Future robotic navigation of an ablation catheter guided by 3D MCG coordinates of the arrhythmogenic target is foreseeable.