The Future of Cardiac Mapping

Abstract

Severe disorders of the heart rhythm that can lead to sudden cardiac death (SCD) are often treated by radio-frequency (RF) catheter ablation. Using fluoroscopy as an imaging guide, the procedure consists of inserting a catheter inside the heart, near the area from which originates the abnormal cardiac electrical activity, then delivering RF currents through the catheter tip to ablate the arrhythmogenic area. Fluoroscopy is a conventional mapping technique that has been extremely useful in understanding and managing simpler arrhythmias. While the fluoroscopic procedure is still used in over 90% of ablations, its limitation in providing a reliable 3D geometry is evident when working upon complex cases like ventricular tachycardia (VT) or atrial fibrillation (AF) ablation. In turn, this results in impaired efficacy and length of the procedure lasting for several hours. Even though operator experience has decreased procedure times, radiation hazards still remain a major issue for the patient. Recent 3D systems which integrate electrophysiological signals with anatomy to provide (3D+ t) geometry are extremely useful in situations where radiation needs to be limited as much as possible, and to increase the efficiency and shorten the duration of RF catheter ablation. During intracardiac mapping, it is not unusual to find sites at which the operator feels ablation is likely to succeed. Three-dimensional systems not only allow the surgeon to mark precise ablation points but also facilitate fixing reference points if the ablation process has to be repeated (Rajnish, 2009). This chapter will summarize the most recent developments in catheter navigation and threedimensional electroanatomic mapping. Conventional fluoroscopy techniques will be described followed by the CARTO and Ensite non-fluoroscopic mapping systems. Advances in ultrasound imaging for cardiac ablation guidance, and futuristic remote navigation technologies such as the Stereotaxis Magnetic Navigation system and the Hansen Sensei Robotic Catheter system will conclude the read.