Ablation Catheter Tips After RF Energy Delivery With and Without Charge Delivery
(A) The left panel shows macroscopic appearances with no charge. There is formation of coagulum on the catheter tip. The right panel shows application of negative charge; there is complete absence of coagulum formation. (B) FESEM images showing the appearances of the catheter tips at low magnification (original magnification ×100). The catheter tips with no negative charge delivery during ablation showed almost complete surface coverage with clot (90 ± 2.5 % ) (left) whereas the negatively charged catheter tips showed complete absence of surface clot coverage (0%, p < 0.01) (right). (C) FESEM at high magnification (original magnification ×1,000) showed that with ablation, the classic lace-like pattern of fibrin clots was obliterated, replaced by an amorphous material (left), indicating that the thermal energy of the ablation had denatured the fibrin clot whereas in the catheter tip with negative charge applied; there is complete absence of coagulum formation, with the metallic surface of the catheter surface easily discerned (right). FESEM = field emission scanning electron microscopy; other abbreviation as in Figure 1.