3-D Electro-Anatomical Mapping

The availability of remote navigation by means of two permanent magnets, the positions of which are computer-controlled, has heralded the start of a new era in cardiac electrophysiology and radiofrequency (RF) catheter ablation of cardiac arrhythmias.1 When located close to the thorax (in navigate position), both magnets create a relatively uniform magnetic field (0.08 Tesla) approximately 15cm inside the chest of the patient. The distal tip of the mapping/ablation catheter is loaded with four small, permanent magnets (see Figure 1). These align with the direction of the externally controlled magnetic field, thus steering it effectively. The elementary movements of a catheter inside the heart include orientation (which is provided by the magnetic field), but also advance and retraction, which require another associated feature – the cardiodrive (Stereotaxis). The cardiodrive is a small system that is stuck to the operating field and connected to a computer-controlled rotating wire, resulting in the advance and retraction of the catheter location.
One of the major advantages of this new technology is the particularly smooth catheter tip; this increases the safety of the procedure by preventing any possibility of heart perforation during its manipulation. The other major advantage of this new approach is the remarkable accuracy and reproducibility of the catheter location. Simultaneously, in recent years a growing number of ablations have been performed using computerised electroanatomic systems such as CARTO®. The realtime position of the catheter tip is permanently calculated and displayed on the computer screen.
This allows virtual-reality reconstruction of the anatomy of the cardiac chamber being studied, as well as its electrophysiological characteristics (voltage and impulse propagation). The combination of the latter with the remote navigation system was a logical and expected evolution.2 The recently released CARTO RMT System has been specifically designed to combine the accurate realtime location of electroanatomic mapping and ablation and the enhanced navigation capabilities of the Remote Magnetic System.

The CARTO RMT System has a distinctive opening screen, and incorporates sophisticated new features such as:

• a ‘Click-and-Go’ option that allows a specific location on the map to
  be marked and immediate transmission of this information to create
  a succession of magnetic fields and push/pull of the catheter that will
  allow it to reach the desired target; and
• design lines that allow the editing and creation of various line shapes,
  which are then exported to the remote magnet system.

This combination of systems has been shown to be useful in clinical situations where precise catheter positioning is difficult to obtain with classical means, or in remote, ‘difficult-to-reach’ areas. Remote navigation allows accurate planning and efficacious ablation of complex arrhythmia cases with a single operator for the first time. It is also useful when teaching or training young cardiologists or beginners in the field.1,2 The combination of the CARTO system with remote navigation will create a safer and more efficient environment for both the patient and the physician, as precision will increase while fluoroscopy time will be reduced.