A phased array probe has multiple small elements at the probe tip that emit a beam, which can be pulsed individually at a computer-calculated timing. This allows for a wide volume region to be swept at a high speed. The pulsed elements emit pressure waves which add up to a single wave front traveling at a set angle. The data from multiple beams is combined as the probe is swept through the examined tissue creating a visual image showing a slice through the object. The AcuNav catheter contains a 64-element phased-array transducer which can penetrate up to 15 cm in the heart. Resolution and depth penetration are inversely related. There is four way directional steering in two bidirectional planes (1) anterior-posterior and (2) right-left. These two knobs allow the operator two steer while the third knob locks the catheter position in a desired position. In addition, the catheter itself can be rotated clockwise or counterclockwise.

Venous access can be obtained either internal jugular or femoral approach. The 90–100 cm catheters advanced through an 8F or 10F venous sheath. ICE access site can be either the ipsilateral or contralateral to the working venous access side. If using the ipsilateral approach, a long 30 cm venous sheath is recommended to reduce entanglement with other devices. Others have recommended contralateral access if the patient weighs less than 35 kg. Closure can be a figure of eight or manual pressure. Infusion of 500 cc saline prior to the procedure dilates the veins and chambers; thus assisting with probe advancement and later device placement. The rigid ICE probe without any flexion should be advanced under fluoroscopic guidance as the probe tip is blunt and can puncture or dissect the vein. There are four traditional views (home, septal, long axis, short axis) used during intracardiac interventions (Fig. 13.1). The chamber closest to the beam and at the top of the display screen is always the chamber where the probe is positioned, usually the right atrium.