July 20, 2013Circulation Arrhythmia and Electrophysiology
Locations of High Contact Force During Left Atrial Mapping in Atrial Fibrillation Patients
Why the study?
Does modulating radiofrequency power based on contact force prevent steam pop and impedance rise during ablation in patients with paroxysmal atrial fibrillation?
Population
18 patients undergoing ablation of paroxysmal atrial fibrillation
Design
Cohort
Authors
Discussion
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Implication
CF-guided power modulation may safely achieve PVI without steam pop; leaves open whether it reduces complications versus standard ablation in randomized trials.
Key Points
- To identify anatomical locations and predictors of high contact force during left atrial mapping, and to evaluate the safety of contact-force-guided power modulation during radiofrequency ablation.
- Mapped 5,682 left atrial and pulmonary vein sites (median 328 sites per patient) in 18 patients undergoing ablation for paroxysmal atrial fibrillation.
- Used a 7.5-Fr irrigated catheter to measure real-time contact force on 3D electroanatomical maps merged with CT scans.
- Evaluated correlations between contact force, electrogram amplitudes, and impedance while titrating radiofrequency power based on force.
- High contact force (≥35 g) occurred at 2% (118/5,682) of sites across 6 clusters, most frequently at the anterior/rightward left atrial roof beneath the ascending aorta (48/113 high-force sites in 17/18 patients).
- Tissue impedance, unipolar potential amplitude, and bipolar potential amplitude demonstrated poor predictive relationships with contact force.
- Contact-force-guided radiofrequency power modulation achieved 100% pulmonary vein isolation with zero steam pops, impedance rises, or pericardial effusions.
Structured PICO
Does modulating radiofrequency power based on contact force prevent steam pop and impedance rise during ablation in patients with paroxysmal atrial fibrillation?
P
Population
18 patients undergoing ablation of paroxysmal atrial fibrillation
I
Intervention
High-density mapping of left atrial/pulmonary veins using a 7.5-Fr irrigated mapping/ablation catheter to measure contact force (CF), followed by radiofrequency power modulation based on CF during ablation
O
Outcome
Locations of high contact force (CF ≥35 g), relationship between CF and atrial potential amplitude/impedance, and procedural safety (steam pop, impedance rise, pericardial effusion)surrogate
High contact force during left atrial mapping clusters at the anterior/rightward roof, and modulating radiofrequency power based on contact force may safely prevent steam pops and impedance rises during ablation.
Cite This Study
Nakagawa et al. (2013) studied this question.