Contact force and impedance decrease during ablation depends on catheter location and orientation: insights from pulmonary vein isolation using a contact force-sensing catheter

Abstract

The effectiveness of RF ablation lesions, as assessed by the initial impedance decrease, is not only dependent on the achieved catheter CF but also on catheter orientation and location.

Characteristics of Cavotricuspid Isthmus Ablation for Atrial Flutter Guided by Novel Parameters Using a Contact Force Catheter

“…These data suggest that FTI is a clinically more relevant CF parameter than total average CF, and catheter orientation during an ablation lesion may be an important factor to decrease recurrence with a more clinically durable ablation lesion made with a higher average force axially (perpendicularly orientated ablation catheter) compared to laterally (parallel or obliquely orientated catheter). A recent study has also demonstrated a similar relationship with better CF with perpendicular compared to parallel or oblique catheter orientation in the left atrium . With respect to the traditional parameters, decrease in impedance was significantly greater with the nonrecurrence group, again implying a relationship with this parameter and lesion integrity.…”

Determinants of Acute and Late Pulmonary Vein Reconnection in Contact Force–Guided Pulmonary Vein Isolation

“…23 Chinitz et al 14 showed that areas of late PVR were associated with sites with small impedance decrease (<10 Ω) during point-by-point PVI. The present data-obtained in exclusively paroxysmal AF undergoing only CF-guided PVIconfirm these findings and imply that obtaining/targeting a minimal impedance decrease of >10 Ω is likely to result in a durable segment.…”

Impact of impedance decrease during radiofrequency current application for atrial fibrillation ablation on myocardial lesion and gap formation

“…A more comprehensive analysis, including all the ranges of CF, might lead to different results. Third, the analysis was performed without taking account of the location of the ablation site or the catheter orientation, whereas a previous report showed that the impedance decrease during RFCA is influenced by these two factors …”

“…In heated tissue by radiofrequency, movement of ions can be promoted and it provides high ion conductivity, resulting in a drop in impedance to current flow. There have been previous reports that a drop in impedance could be correlated with CF and predictive of the ablation effect or clinical outcome, but the impact of an impedance drop remains to be fully elucidated. The aim of this study was to clarify whether a decrease in impedance could predict myocardial injury from the application of RFCA in the human beating heart and whether it could predict the acute outcome of PVI.…”