RESUMO
<p><b>OBJECTIVE</b>The purpose of this study was to observe histopathological changes post cryoablation in canine myocardium, to characterize the specific ablation lesion post cryoablation.</p><p><b>METHODS</b>Cryothermal ablation was applied on myocardium (both epicardium and endocardium) of 14 mongrel dogs with different ablation parameters (-25 degrees C x 4 min, -50 degrees C x 4 min, -75 degrees C x 4 min, -75 degrees C x 2 min, -75 degrees C x 6 min, -75 degrees C x 8 min). Lesion dimensions and histopathologic changes were observed.</p><p><b>RESULTS</b>The discrete, sharply delimited lesions were detected in cryoablated myocardium. Histologically, cryoablation in all temperatures studied induced heterogeneous necrosis of the myocardium. Lesion dimensions are related to freezing time and temperature.</p><p><b>CONCLUSION</b>Cryoablation is a feasible and preferably choice for clinical application due to its controllable myocardium lesions.</p>