Characteristics of Ice Impedance Recorded From a Ring Electrode Placed at the Anterior Surface of the Cryoballoon

Avitall, Boaz; Kalinski, Arthur; Kocheril, G. Stephen; Lizama, Ken Shibata; Coulombe, Nicolas; Laske, Timothy G.

doi:10.1161/circep.117.005949

Cited by 6 publications

(9 citation statements)

References 14 publications

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“…Recently, the results of a first promising biophysical parameter that measures ice formation have been presented. This study is a proof of concept performed in an animal model, so we have to wait for clinical applicability …”

Section: Discussionmentioning

confidence: 99%

Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study

Molenaar

Timmermans

Hesselink

et al. 2019

Pacing Clinical Electrophis

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BackgroundThe second‐generation cryoballoon significantly improves outcome of pulmonary vein isolation (PVI) but may cause more complications than the first generation. Currently, no consensus regarding optimal cryoballoon application time exists. The 123‐study aimed to assess the minimal cryoballoon application duration necessary to achieve PVI (primary endpoint) and the effect of application duration on prevention of phrenic nerve injury (PNI).MethodsPatients <75 years of age with paroxysmal atrial fibrillation, normal PV anatomy, and left atrial size <40 cc/m² or <50 mm were randomized to two applications of different duration: “short,” “medium,” or “long.” A total of 222 patients were enrolled, 74 per group.ResultsDuration per application was 105 (101‐108), 164 (160‐168), and 224 (219‐226) s and isolation was achieved in 79, 89, and 90% (P < 0.001) of the PVs after two applications in groups short, medium, and long, respectively. Only for the left PVs, the success rate of the short group was significantly less compared to the medium‐ and long‐duration groups (P < 0.001). PNI during the procedure occurred in 19 PVs (6.5%) in the medium and in 20 PVs (6.8%) in the long duration groups compared to only five PVs (1.7%) in the short duration group (P < 0.001).ConclusionsShort cryoballoon ablation application times, less than 2 min, did affect the success for the left PVs but not for the right PVs and resulted in less PNI. A PV tailored approach with shorter application times for the right PVs might be advocated.

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Section: Discussionmentioning

confidence: 99%

Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study

Molenaar

Timmermans

Hesselink

et al. 2019

Pacing Clinical Electrophis

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“…The conductive properties of ice have been well described in biological tissues . In our initial publication on this subject, we have reported once the impedance level has reached ≥500 Ω in ≤90 sec of freeze time, the cryoapplication can be terminated at 90 sec with 100% likelihood of achieving sustained PVI …”

Section: Discussionmentioning

confidence: 94%

“…Impedance rise of ≥500 Ω before 90 sec of freeze time, 10 to 20 sec prolongation of the cryoapplication leads to several thousand ohms impedance rises. Careful analysis of the extracardiac tissues did not document phrenic, esophageal, or lung damage …”

Section: Discussionmentioning

confidence: 97%

“…[12][13][14][15] In our initial publication on this subject, we have reported once the impedance level has reached ≥500 Ω in ≤90 sec of freeze time, the cryoapplication can be terminated at 90 sec with 100% likelihood of achieving sustained PVI. 2 In this investigation, we have examined the early sequence of impedance rise, particularly between 30 to 60 sec of cryoapplication to provide the clinician with an early indicator of efficacy with a single cryofreeze. In addition, we characterized the unique features of cryo impedance associated with 90 sec successful PVI (type I impedance), In this preclinical assessment, we have determined for the first time that within the first 30 to 60 sec of cryoapplication it is possible to define the quality of the cryofreeze and the time needed to achieve durable PVI based on the early rise in ice impedance.…”

Section: As Shown Inmentioning

confidence: 99%

“…With the introduction of the Arctic Front Advance balloon, the freeze time has evolved to minimize extracardiac damage while maintaining clinical efficacy. Recently, Avitall et al have examined the relationship between ice formation on the anterior surface of the balloon and electrical impedance changes. The impedance was measured between a ring electrode positioned on the 23‐mm cryoballoon catheter shaft 2 mm from the anterior surface of the balloon and a reference ring electrode positioned on the shaft behind the balloon (Figure ).…”

Section: Introductionmentioning

confidence: 99%

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Determination of single cryoablation outcome within 30 to 60 seconds of freezing based on ice impedance

Avitall

Lizama

Kalinski

et al. 2019

Cardiovasc electrophysiol

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BackgroundA direct indicator of effective pulmonary vein isolation (PVI) based on early ice formation is presently lacking.ObjectiveThe initial impedance rise within 30 to 60 seconds (sec) of single cryoablation relating to ice on the distal surface of the cryoballoon could; predict effective PVI with early termination, the need for prolonging the cryoablation, or failure to achieve effective ablation.MethodsImpedance measurements were taken between two ring electrodes, at the anterior balloon surface and at the shaft behind the balloon. Ice covering the anterior ring leads to impedance rise. Single cryoablation (eight animals, 37 veins) was applied for 90 to 180 sec. Cryoapplication was terminated if the impedance reached ≥500 Ω. Impedance levels at ≤60 sec of cryoablation were divided into three groups based on the characteristics of the impedance rise. PVI was confirmed acutely and at 45 ± 9 days recovery by electrophysiology mapping and histopathology.ResultsAt 60 sec of freezing, an impedance rise of 34.1 ± 15.2 Ω (13‐50 Ω) and slope of the impedance rise (measured during 15‐30 sec of cryoapplication) less than 1 Ω/sec resulted in failed PVI. An impedance rise of 104.4 ± 31.5 Ω (76‐159 Ω) and slope of 2 Ω/sec resulted in 100% PVIs. An impedance rise of 130.9 ± 137.8 Ω (40‐590 Ω) and slope of 10 Ω/sec resulted in 100% PVIs with early termination at 90 sec.ConclusionThe efficacy of single cryoablation can be defined within 30 to 60 sec based on ice impedance. Three unique impedance profiles described in this investigation are associated with the uniformity and thickness of the ice buildup on the anterior surface of the balloon. One cryoablation with an adequate impedance rise is needed for successful outcomes.

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Temperature drop in thawing phase reflects sufficient ice formation and better outcome of pulmonary vein isolation using second-generation cryoballoon

Kaneshiro

Hijioka

Matsumoto

et al. 2019

J Interv Card Electrophysiol

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Characteristics of Ice Impedance Recorded From a Ring Electrode Placed at the Anterior Surface of the Cryoballoon

Cited by 6 publications

References 14 publications

Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study

Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study

Determination of single cryoablation outcome within 30 to 60 seconds of freezing based on ice impedance

Temperature drop in thawing phase reflects sufficient ice formation and better outcome of pulmonary vein isolation using second-generation cryoballoon

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