Limitations
There are some limitations in our work that must be acknowledged. First, results need to be interpreted as hypothesis-generating and in light of the small and heterogeneous sample size, due to the use of different imaging modalities and different ablation modalities.
No direct comparisons between ICE and IVUS were made by imaging the same PVs with both modalities. No other imaging modality or histopathology were available as reference for the PVs measurements obtained with ICE and IVUS to ascertain which of the two imaging modalities gave more accurate measurements. However, this did not preclude confirming the feasibility of both ICE and IVUS for LA wall imaging, since comparable wall thickness measurements were obtained and similar acute changes in wall thickness were detected with both imaging modalities.
Pullback was manual rather than automatic. This precluded the precise comparison of distal cross-sections before and after ablation.
Imaging during energy delivery was not attempted as the same trans-septal access was used for either ablation catheter or imaging catheter. However, simultaneous imaging might not have been possible due to spatial interference, especially when using cryo or laser balloon catheters, and/or due to artifacts created by irrigation of the RF catheter.