DISCUSSION
Our pilot study was conducted to compare ICE and IVUS for real-time LA
wall imaging and for detection of acute tissue changes produced by
different ablation energies during PVI catheter ablation. Although both
ICE and IVUS probes image in the axial plan, providing cross-sectional
images of the vessel (or chamber of interest) and surrounding tissues,
their transducers use different ranges of ultrasound frequencies. The
catheter designs are also different: the IVUS catheter has a smaller
size (6F) and uses a mono-rail system, with the distal portion of the
catheter advanced over a guidewire for better support and stability,
while the ICE catheter has a bigger size (9F) and no central lumen. We
chose to compare a 9MHz ICE catheter with a 20MHz IVUS probe to
investigate which ultrasound frequency would give the best compromise
between contrast resolution and image penetration for PVs imaging.