Suboptimal ostial level isolation in pulmonary veins after cryoballoon ablation frequently indicates need for additional segmental ablations to improve outcomes

The level of pulmonary vein isolation (PVI) achieved using cryoballoon ablation (CBA) has been the subject of controversy. Pulmonary vein (PV) occlusion using the currently available, fixed-diameter cryoballoons can yield suboptimal ostial PVI and arrhythmogenic sites like spared carina. A segmental, non-occlusive cryoballoon ablation (NOCA) strategy could overcome this limitation of CBA.

To study by three-dimensional electroanatomic left atrial (LA) voltage maps after CBA the number of ostial level PVI and spared, non-ablated carina’s.

To define the need for segmental NOCA to obtain antral level PVI and optimal carina ablation.

EnSite voltage maps post-CBA were studied in 100 patients undergoing Achieve catheter–guided CBA. Ostial level PVI was defined as an ablated PV region (<0,5mV) until (but not surpassing) the level of the LA-PV junction.

Post-CBA voltage maps depicted ostial PVI level in 110 out of 392 veins (28%), with predominance of the left superior PV: 39/92 (42.4%) versus 2/8 (25%), 25/92 (27%), 23/100 (23%), 21/100 (21%) respectively for the left common PV, left inferior PV, right superior PV and right inferior PV. A spared carina was present in 11/100 (11%) left PVs and 16/100 (16%) right PVs after CBA. Overall, in 68 patients there was a need for segmental NOCA to achieve antral PVI. Spatially, for both PV sides, preferential segments showing ostial level PVI were situated at the posterior wall (posterosuperior 18, posteromedian 7, posteroinferior 15 for the left veins and posterosuperior 9, posteromedian 9, posteroinferior 10 for the left veins).

Suboptimal ostial level PVI and ablation sparing the carina occurs in a substantial amount of PVs treated by conventional CBA indicating the need for segmental NOCA to extend the lesion set to an antral level or subsequently ablate the spared carina.