Why “Dielectric”?
Dielectric concept is based on gradients in the electrical field promoted by the different cardiac structures, such as the endocardial surface, cardiac veins and heart valves. The KODEX-EPD imaging system (3) properly creates high-resolution images of cardiac anatomy by exploiting the distinct dielectric properties of biological tissue. The system receives and analyzes the electrical field transmission and reflection from all catheter used in the procedure. (4). This “gradients of the  electrical field” is sensed by the system and used to calculate the geometric characteristics of  the three-dimensional (3D) image. With this technique, it is possible to collect anatomic information without immediate physical surface contact a few  millimeters ahead of the catheter electrodes, resulting in a certain degree of “far-field imaging”. Moreover, tissue thickness was measured by means of the Wall Viewer (WV) function, assessing a series of dielectric signals derived directly from real-time local interrogation of the catheter-tissue interface. The electric-field characteristics (e.g., the field shape) and dielectric tissue signature are acquired when the ablation catheter is stable and engaged with the endocardial wall momentarily (<1.5 sec). The Wall Viewer is displayed in millimeters and as a color code scale. The characteristic electrical field distribution can differentiate correctly between 7, 4 and 1.35 mm currently corresponds with the regional average wall thickness, although it can be calibrated  to match the ECG gated diastolic phase as utilized in computed tomography-based atrial wall thickness measurement (5,6)