Influence of the irrigation flow pattern and catheter tip design on the lesion formation: an ex vivo experimental model.

BACKGROUND: Lesion formation during catheter ablation is influenced by the power, contact force (CF), time, and catheter stability. However, the influence of the irrigation effects on lesion formation remains unknown. METHODS: An ex vivo experiment using conductive gel was performed. Using three different catheter designs (TactiFlex ™ SE [TF], IntellaNav MiFi ™ OI [MiFi], QDOT MICRO™ [QDOT]), a cross-sectional analysis of the lesion size and surface lesion type of 10g/40W lesions with a combination of various ablation times was performed in protocol 1. A longitudinal analysis (combination of various powers [30, 40, and 50W] and various ablation times with a 10g setting) was performed to investigate the influence of the auto-regulated irrigation system (QDOT) on lesion formation in protocol 2. RESULTS: The lesion formation with the QDOT catheter tended to create larger ablation lesions, while that with the TF catheter created smaller lesions than the other catheters. The lesion surface characteristics were divided into two patterns: ring (MiFi catheter and QDOT) and crescent (TF) patterns. The auto-regulated irrigation system did not influence the lesion formation, and the relationship between the lesion formation and RF energy exhibited similar changes regardless of the ablation power setting. CONCLUSION: The lesion formation and lesion surface characteristics differed among the different irrigation tip designs. An auto-regulated irrigation system did not affect the lesion creation or surface lesion characteristics. Care should be given to the inter-product differences in the lesion characteristics during RF catheter ablation, partly due to the irrigation flow control and tip design.