Pulsed field ablation (PFA) is proposed as a useful modality in AF treatment, but factors determining the field distribution, and lesion transmurality and geometry have not been fully characterized. To understand the physics behind the tissue response to PSA, we propose a quasi-dynamic PFA model that can predict the tissue conductivity when electroporation equilibrium is achieved, and identify tissue regions that undergo fully irreversible electroporation (IRE) Model parameters include: tissue conductivity at baseline (0.2 S/m) and after complete electroporation (0.8 S/m), critical depth of the electric field for reversible electroporation (RE, 200 V/m and IRE, 450 V/m), and the applied pulsed voltage amplitude. The iterative model yields the steady-state solution with a tissue conductivity map, clearly identifying regions of IRE. The model employed a circular catheter with 9 - 3 mm electrodes fired sequentially using a 1500 V and 3000 V pulse. The steady-state IRE regions are shown (figure) with an estimated IRE lesion surface area and volume of 780 mm2 and 1411 mm3, respectively, at 1500 V, and 1178 mm2 and 2760 mm3, respectively, at 3000 V. Lesion discontinuity is observed at 5.0 mm depth with 1500 V and 7.2 mm with 3000 V. Transverse views through the lesions show maximum lesion depth at each voltage amplitude. The tissue conductivity profiles through predicted lesions show the formation of gaps in the lesion pattern. (Figure 1) The proposed quasi-dynamic model yields steady-state tissue conductivity maps, shows full IRE tissue regions, and confirms larger lesions with higher pulse amplitudes. Future work will predict time-based tissue response given specific pulse duration and delivery of sequential pulses and compare numerical and experimental results.