Three-dimensional ultrasound for image-guided mapping and intervention: methods, quantitative validation, and clinical feasibility of a novel multimodality image mapping system.

Background: Multiple factors create discrepancies between electroanatomic maps and merged, preacquired computed tomographic images used in guiding atrial fibrillation ablation. Therefore, a Carto-based 3D ultrasound image system (Biosense Webster Inc) was validated in an animal model and tested in 15 atrial fibrillation patients.

Methods And Results: Twelve dogs underwent evaluation using a newly developed Carto-based 3D ultrasound system.

Mechanism of tissue heating during high intensity focused ultrasound pulmonary vein isolation: implications for atrial fibrillation ablation efficacy and phrenic nerve protection.

Introduction: The purpose of this study was to examine tissue temperatures around pulmonary veins (PVs) during high intensity focused ultrasound (HIFU) balloon ablation for atrial fibrillation. The thermodynamics and extent of PV and phrenic nerve (PN) heating during HIFU ablation have not been established.

Methods And Results: Tissue temperatures were recorded from epicardial thermocouples at right superior (RS) PV orifice and PN in eight dogs undergoing 51 RSPV HIFU ablations (40 seconds, 40 W).

A systematical analysis of in vivo contact forces on virtual catheter tip/tissue surface contact during cardiac mapping and intervention.

Introduction: While catheter tip/tissue contact has been shown to be an important determinant of ablative lesions in in vitro studies, the impact of contact on the outcomes of mapping and ablation in the intact heart has not been evaluated.

Methods And Results: Twelve dogs underwent atrial ablation guided by the Senesitrade mark robotic catheter remote control system. After intracardiac ultrasound (ICE) validation of contact force measured by an in-line mechanical sensor, the relationship between contact force and individual lesion formation was established during irrigated-tipped ablation (flow 17 mL/sec) at 15 watts for 30 seconds.