“…4,5 Based on available data, myocardial cells are rendered electrically dormant (ie, reversible ion channel block) at 120 C to 125 C with irreversible, lethal effects achieved at temperatures of -20 C to -50 C. 6,7 Although PV occlusion likely augments the "magnitude of the freeze," optimal tissue contact and not necessarily PV occlusion, which in itself implies the same, is quintessential for creating durable cryolesions. This notion is further supported by finite element modeling data 8 and clinically corroborated when performing nonocclusive cryoballoon ablation (NOCA) to target large-sized PVs in a segmental approach, as in the case of large, common PV ostia 9 and the left atrial (LA) roof (NOCAROOF) [10][11][12][13] and posterior wall (PW) (NOCALAPW). [14][15][16][17][18] In fact, PV occlusion using currently available, fixed-diameter cryoballoons (23/28 mm) is more likely to yield suboptimal results (ie, an ostial level PVI) when treating large-sized PVs or patients with persistent/long-standing persistent AF who typically exhibit large LA and PV antra.…”