RESUMO
PURPOSE: We investigated the development of in vitro lesion formation in relation to ablation time and power delivery using 4-mm, non-irrigated, platinum-iridium (Pt/Ir), and gold-tip catheters. METHODS: Radiofrequency catheter ablation was performed on porcine liver preparations in a 5-60-s time range with 5 s increments applied at different lesion sites. Each series was repeated four times for both catheters. The lesion volume, the delivered energy, and the ablation power curves were analyzed in 96 ablations. RESULTS: The delivered energy was higher and the lesion volume was significantly larger when using a gold-tip catheter. The lesion volume that was created with the Pt/Ir-tip electrode within 60 s was created after a shorter 40 s ablation period with the gold-tip electrode (Au, 40 s, 345 ± 75 mm(3) vs. Pt/Ir, 60 s, 328 ± 30 mm(3)). CONCLUSION: The gold-tip catheters had a lower tip temperature resulting in higher energy delivery due to the better thermo-conductivity of the gold alloy. A significantly higher lesion volume and a faster lesion creation were found for gold catheters as compared to Pt/Ir catheters. Gold-tip catheters can create the same adequate lesion within 33.3 % less ablation time due to the higher values of delivered energy as compared to those observed with the use of Pt/Ir catheters.
