Electromagnetic Mapping During Complex RF Ablations

Electromagnetic mapping has made possible the routine approach to complex arrhythmia mapping. Originally, it was developed to facilitate accessory pathway location, but it only complicated solitary pathway ablation. Especially, with the introduction of atrial fibrillation ablation, the electromagnetic mapping has become an irreplaceable component of this procedure. Latter, this 3-dimentional mapping method facilitated ventricular foci ablation in patients with ventricular tachycardia. During the last decade, the application of this mapping method is continuously extended and applied to a large number of complex arrhythmia cases. The electromagnetic mapping is based on minimal magnetic field generation around the tip of the catheter and several antennas, located in a special hardware, called location pad, detect this field. In the near future the location pad will be replaced by an intracardiac detection system. As multiple antennas record the signal, the location pad precisely localizes the catheter tip. By apposition of a location on the endocardial surface and the catheter tip, a virtual map of the cardiac chamber is obtained. Multiple points are represented in space and finally, a continuous wall is completed. Moreover, the catheter records the electrical activity in its vicinity, and the electrical flow can be superimposed on the location in the space. A color-coding localizes the starting point of the arrhythmia and the current flow from it. As of today, an advanced generation is used and data from other imaging systems are merged with the electromagnetic picture. First, magnetic resonance data was merged with the electroanatomic mapping, but today cardiac computed tomography and echo picture might also be merged. Using these merged pictures the anatomical presentation more accurately represents the anatomical structure.