Area Under the Real‐Time Contact Force Curve (Force–Time Integral) Predicts Radiofrequency Lesion Size in an In Vitro Contractile Model

Shah, Dipen; Lambert, Hendrik; Nakagawa, Hiroshi; Langenkamp, Arne; Aeby, Nicolas; Leo, Giovanni Di

doi:10.1111/j.1540-8167.2010.01750.x

Cited by 236 publications

(210 citation statements)

References 7 publications

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“…18 As contact force is an important factor in lesion creation, increased catheter-tissue contact has now been associated with a larger impedance decrease during RF ablation, 12,17,19 and in the absence of sufficient catheter-tissue contact, an impedance decrease of 10 O cannot be achieved. 12 However, contact force is only one of several factors associated with lesion creation (ablation power, duration, surface area, catheter stability and tip-to-tissue contact, and local tissue resistance being other examples) and, when measured in isolation, does not indicate effective tissue destruction.…”

Section: Role Of Contact Forcementioning

confidence: 99%

Impedance-guided Radiofrequency Ablation: Using Impedance to Improve Ablation Outcomes

Chinitz

Michaud

Stephenson

2017

J Innov Cardiac Rhythm Manage

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ABSTRACT. Despite the achievement of acute conduction block during catheter ablation, the recovery of conduction at previously ablated sites remains a primary factor implicated in arrhythmia recurrence after initial ablation. Real-time markers of adequate ablation lesion creation are needed to ensure durable ablation success. However, the assessment of acute lesion formation is challenging, and requires interpretation of surrogate markers of lesion creation that are frequently unreliable. Careful monitoring of impedance changes during radiofrequency catheter ablation has emerged as a highly specific marker of local tissue destruction. Ablation strategies guided by close impedance monitoring during ablation applications have been demonstrated to achieve high levels of success for ablation of atrial fibrillation. Impedance decrease during ablation may therefore be used as an additional endpoint beyond acute conduction block, in order to improve the durability of ablation lesions. In this manuscript, available methods of real-time lesion assessment are reviewed, and the rationale and technique for impedance-guided ablation are described.

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Section: Role Of Contact Forcementioning

confidence: 99%

Impedance-guided Radiofrequency Ablation: Using Impedance to Improve Ablation Outcomes

Chinitz

Michaud

Stephenson

2017

J Innov Cardiac Rhythm Manage

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“…The FTI reflects the duration (in seconds) of the average contact force (in grams) applied during RF application, with lesion size correlating linearly with measured FTI (grams/ seconds). 4 A cut-off of 400 g/s or more for FTI has been associated with a higher success rate and lower recurrence of pulmonary vein reconnection compared with an FTI of lower than 400 g/s. Hence, an FTI Z400 g/s has been suggested as a surrogate end-point to predict the creation of transmural lesions in RF.…”

Section: Introductionmentioning

confidence: 99%

Lesion Size Index in Maximum Voltage-Guided Cavotricuspid Ablation for Atrial Flutter

Boles

Gül

Fitzpatrick

et al. 2017

JICRM

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ABSTRACT. The application of optimum contact force (CF) can be used to improve ablation procedure success and safety. The lesion size index (LSI) is a novel dimensionless contact force parameter that allows for an accurate estimation of lesion volume in real time by integrating contact force (grams), duration (seconds) and power (watts). The aim was to correlate LSI values with current contact force parameters to achieve successful and safe bidirectional block of the cavotricuspid isthmus (CTI) using a maximum voltage-guided (MVG) ablation strategy. Fifteen consecutive patients (age 69±7.9 years, nine males) with symptomatic atrial flutter (AFL) were evaluated and compared with 23 control (age 66.3 ± 10.4 years, 16 males) non-contact forceguided ablation cases. Irrigated-tip force-sensing ablation catheters (TactiCath Quartzt, St. Jude Medical, St. Paul, MN, USA) were used in the CF group to achieve the primary endpoint of complete bidirectional block of the isthmus. In the CF group, a total of 233 radiofrequency (RF) applications were examined. A mean LSI of 6.4 ± 1.0 correlated with a force-time integral (FTI) of 581.2±230.9 g/s and an average CF of 13.9±4.9 g concurrently. Intraprocedural, fluoroscopy time and RF time demonstrated lower trends in the CF group, but no significance with respect to these trends was observed. The secondary endpoint of no reconnection within 20 min after the procedure was equally attained in both groups, and, likewise, the level of safety was comparable. An LSI value of 45 represents a new effective parameter in MVG ablation for the cavotricuspid region that demonstrates a safe profile. Guidance of CTI ablation using LSI and other contact force parameters of CF 13.9 ± 4.9 g and FTI 581.2 ± 230.9 g/s demonstrated highly effective and safe outcomes.

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“…In addition, the incidence of steam pop and thrombus increased with CF. 5 Shah et al 6 have examined the delivery of RF energy during constant contact at 20 g, variable contact with a 20 g peak and 10 g nadir and intermittent contact with a 20 g peak and 0 g nadir with loss of contact.…”

Section: Contact Force: a Critical Determinant Of Lesion Sizementioning

confidence: 99%

Increasing the Single-Procedure Success Rate of Pulmonary Vein Isolation

Duytschaever

O’Neill

Martinek

2017

Arrhythmia &Amp; Electrophysiology Review

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To improve the single-procedural success and long-term outcomes of catheter ablation techniques for AF, there is a need for durable, contiguous and transmural lesions encircling the pulmonary veins (PV). Measurement of contact force (CF) between the catheter tip and the target tissue can optimise ablation procedures. A new approach to obtain single-procedure durable PV isolation (PVI) using the latest CF technology combined with the CARTO VISITAG ™ Module with Ablation Index (Biosense Webster) has been shown in small studies to almost eliminate recurrence of paroxysmal AF at 1-year follow up and to make PVI procedures more reproducible. The use of a standardised workflow is expected to increase the reproducibility of results and to increase the efficiency of PVI procedures. KeywordsCatheter ablation, contact force, pulmonary vein isolation, CARTO VISITAG™ Module, ablation index Disclosure: Mark O'Neill has received research support, honoraria and consulting fees from Biosense Webster; and research support, honoraria and consulting fees from Abbott/St Jude. Mattias Duytschaever has received honoraria for presentation and consulting from Biosense Webster. Acknowledgement:The authors are grateful to the technical editing support provided by Katrina Mountfort of Medical Media Communications (Scientific) Ltd, which was funded by Biosense Webster. Received A R R H Y T H M I A & E L E C T R O P H Y S I O L O G Y R E V I E W 218 Diagnostic Electrophysiology and Ablation Clinical Impact of Contact Force TechnologiesOptimising Outcomes in Pulmonary Vein Isolation What About Randomised Trials?The importance of optimal contact has been demonstrated in the prospective randomised non-inferiority Ablation Catheter Study for Atrial Fibrillation (TOCCASTAR) study, which compared the TactiCath catheter with a non-CF-sensing catheter (NAVISTAR ® ThermoCool ® ;Biosense Webster) in 300 patients undergoing catheter ablation of PAF. 14 When the CF arm was stratified into optimal CF (≥90 % ablations with ≥10 g) and non-optimal CF groups, effectiveness was achieved in 75.9 % versus 58.1 %, respectively (p=0.018).In a recent randomised trial performed at seven UK centres, 117 patients undergoing first-time PAF ablation were randomised to ablation with (CF-on) or without (CF-off) CF data available to the operator. A reduction in acute PV reconnection rates was seen in the CF-on group (22 % versus 32 %, p=0.03) but there was no significant difference in 1-year success rates (49 % versus 52 %, p=0.9). Furthermore, there was no difference in major complication rates, procedural times and fluoroscopy times. The investigators concluded that CF data availability as used in this study was associated with improved catheter control but did not impact on the clinical outcome. This confirms that CF is only one of multiple factors that determine lesion efficacy and safety. 15Three other small prospective randomised studies have compared CF versus non-CF-sensing catheter ablation. These studies have shown that some operators are able to est...

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Area Under the Real‐Time Contact Force Curve (Force–Time Integral) Predicts Radiofrequency Lesion Size in an In Vitro Contractile Model

Abstract: Lesion size correlates linearly with measured contact FTI. Constant contact produces the largest and intermittent contact the smallest lesions despite constant RF power and identical peak contact forces.

Cited by 236 publications

References 7 publications

Impedance-guided Radiofrequency Ablation: Using Impedance to Improve Ablation Outcomes

Impedance-guided Radiofrequency Ablation: Using Impedance to Improve Ablation Outcomes

Lesion Size Index in Maximum Voltage-Guided Cavotricuspid Ablation for Atrial Flutter

Increasing the Single-Procedure Success Rate of Pulmonary Vein Isolation

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