Introduction
The QDOT‐MicroTM catheter is a novel irrigated contact force (CF) sensing catheter which benefits from thermocouples for temperature monitoring, allowing temperature‐flow‐controlled ...(TFC) ablation. We compared lesion metrics at fixed ablation index (AI) value during TFC‐ablation and conventional power‐controlled (PC)‐ablation.
Methods
A total of 480 RF‐applications were performed on ex‐vivo swine myocardium with predefined AI targets (400/550) or until steam‐pop occurred, using the QDOT‐MicroTM (TFC‐ablation) and Thermocool SmartTouch SFTM (PC‐ablation).
Results
Both TFC‐ablation and PC‐ablation produced similar lesions in volume (218 ± 116 vs. 212 ± 107 mm3, p = .65); however, lesions using TFC‐ablation were larger in surface area (41.3 ± 8.8 vs. 34.8 ± 8.0 mm2, p < .001) and shallower in depth (4.0 ± 1.0 vs. 4.2 ± 1.1 mm, p = .044). Average power tended to be lower in TFC‐alation (34.2 ± 8.6 vs. 36.9 ± 9.2, p = .005) compared to PC‐ablation due to automatic regulation of temperature and irrigation‐flow. Although steam‐pops were less frequent in TFC‐ablation (24% vs. 15%, p = .021), they were particularly observed in low‐CF (10 g) and high‐power ablation (50 W) in both PC‐ablation (n = 24/240, 10.0%) and TFC‐ablation (n = 23/240, 9.6%). Multivariate analysis revealed that high‐power, low‐CF, long application time, perpendicular catheter orientation, and PC‐ablation were risk factors for steam‐pops. Furthermore, activation of automatic regulation of temperature and irrigation‐flow was independently associated with high‐CF and long application time while ablation power had no significant relationship.
Conclusions
With a fixed target AI, TFC‐ablation reduced the risk of steam‐pops, producing similar lesions in volume, but with different metrics in this ex‐vivo study. However, lower CF and higher power in fixed‐AI ablation may increase the risk of steam‐pops.
When the ablation index was fixed during radiofrequency ablation, temperature‐flow‐controlled ablation provided lesions with larger surface, shallower depth and similar volume with lower incidence of steam‐pops compared to conventional power‐controlled ablation.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Introduction
Isolation of the left atrial appendage (LAA) is often performed in persistent atrial fibrillation (AF). Propagation patterns in the LAA during AF remain to be elucidated. We sought to ...characterize propagation patterns in the LAA during AF in persistent AF.
Methods
Persistent AF patients undergoing catheter ablation were studied. Pulmonary vein isolation (PVI) was performed during continuous AF. If AF was not terminated by PVI, bi‐atrial mapping was performed using a multi‐electrode catheter during AF. Maps were collected at each site for 30 seconds and analyzed offline with a novel software, CARTOFINDER. This software made automatic determinations of whether activation was focal or rotational. The left atrium (LA) was divided into five regions, of which the LAA was one, and the right atrium (RA) into three.
Results
Eighty patients were studied (62 ± 10 years, 65 males). On average, 9.6 ± 2.2 and 4.1 ± 1.2 maps were created in the LA and RA, respectively. The LAA was mapped in 70 patients, resulting in 85 maps. In the LAA, activation was identified as focal more often than rotational (64 91% vs 10 14% patients, P < .001), seven patients displayed both. The number of focal activation events was greatest in the LAA (28.5 events/30 seconds interquartile range, 15‐54) of the eight atrial regions. During focal activation, sites designated as earliest activation frequently covered a wide area, rather than being localized to a discrete site (5.4 ± 3.1 electrodes).
Conclusions
The results of this study suggest that focal activation is a major mechanism underlying the arrhythmogenicity of the LAA in persistent AF.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Background:Pulmonary vein (PV) isolation (PVI) with balloon-based visually guided laser ablation (VGLA) is useful for treating atrial fibrillation (AF), but phrenic nerve injury (PNI) is an important ...complication. We investigated the predictors of developing PNI during VGLA.Methods and Results:We included 130 consecutive patients who underwent an initial VGLA of non-valvular paroxysmal AF. Twenty patients developed PNI during the PVI. The patients with PNI had a significantly larger right superior PV ostial area (RSPVOA) than the other patients (mean ±SD 284.7±47.0 vs. 233.1±46.4 mm2, respectively; P<0.01). Receiver operating characteristic analyses revealed that the area under the RSPVOA curve was 0.79 (95% confidence interval CI 0.69–0.90) with an optimal cut-off point of 238.0 mm2(sensitivity, 0.58; specificity, 0.95). In multivariate analyses, a large RSPVOA (HR 1.02, 95% CI 1.01–1.03, P<0.01) and small balloon size (HR 0.70, 95% CI 0.50–0.99, P=0.04) were independent risk factors for PNI during VGLA. PNI remained in 13 patients after the procedure, but 12 of these patients recovered from the PNI during the follow-up period.Conclusions:The incidence of PNI during VGLA was relatively high, but PNI improved in most cases. A large RSPVOA and small balloon size were predictors of PNI during VGLA.
Background:Sedation during pulmonary vein isolation (PVI) for atrial fibrillation often provokes a decline in left atrial (LA) pressure (LAP) under atmospheric pressure and increases the risk of ...systemic air embolisms. This study aimed to investigate the efficacy of adaptive servo-ventilation (ASV) on the LAP in sedated patients.Methods and Results:Fifty-one consecutive patients undergoing cryoballoon PVI were enrolled. All patients underwent sedation using propofol throughout the procedure. After the transseptal puncture and the insertion of a long sheath into the LA, the LAP was measured. Then, the ASV treatment was started, and the LAP was re-measured. The LAP before and after the ASV support was investigated. Before ASV, the LAP during the inspiratory phase was significantly smaller than that during the expiratory phase (4.9±5.4 mmHg vs. 14.0±5.2 mmHg, P<0.01). The lowest LAP was −2.2±5.1 mmHg and was under 0 mmHg in 37 (73%) patients. After the ASV, the LAP during the inspiratory phase significantly increased to 8.9±4.1 mmHg (P<0.01), and lowest LAP increased to 4.7±5.9 mmHg (P<0.01). The negative lowest LAP value became positive in 30/37 (81%) patients. There were no statistical differences regarding obstructive sleep apnea (OSA), obesity, gender, or other comorbidities between patients with and without a negative lowest LAP after ASV support.Conclusions:ASV is effective for increasing the LAP above 0 mmHg and might prevent air embolisms during PVI.
Background:Recently, identification of independent risk factors for ischemic stroke in Japanese non-valvular atrial fibrillation (NVAF) patients was made by analyzing the 5 major Japanese registries: ...J-RHYTHM Registry, Fushimi AF Registry, Shinken Database, Keio interhospital Cardiovascular Studies, and the Hokuriku-Plus AF Registry.Methods and Results:The predictive value of the risk scheme in Japanese NVAF patients was assessed. Of 16,918 patients, 12,289 NVAF patients were analyzed (mean follow up, 649±181 days). Hazard ratios (HRs) of each significant, independent risk factor were determined by using adjusted Cox-hazard proportional analysis. Scoring system for ischemic stroke was created by transforming HR logarithmically and was estimated by c-statistic. During the 21,820 person-years follow up, 241 ischemic stroke events occurred. Significant risk factors were: being elderly (aged 75–84 years E, HR=1.74), extreme elderly (≥85 years EE, HR=2.41), having hypertension (H, HR=1.60), previous stroke (S, HR=2.75), type of AF (persistent/permanent) (T, HR=1.59), and low body mass index <18.5 kg/m2(L, HR=1.55) after adjusting for oral anticoagulant treatment. The score was assigned as follows: 1 point to H, E, L, and T, and 2 points to EE and S (HELT-E2S2score). The C-statistic, using this score, was 0.681 (95% confidence interval CI=0.647–0.714), which was significantly higher than those using CHADS2(0.647; 95% CI=0.614–0.681, P=0.027 for comparison) and CHA2DS2-VASc scores (0.641; 95% CI=0.608–0.673, P=0.008).Conclusions:The HELT-E2S2score may be useful for identifying Japanese NVAF patients at risk of ischemic stroke.
Purpose
Clinical implication of local impedance (LI) for radiofrequency (RF) ablation has not been fully established. This study aimed to investigate this point using IntellaNav MiFi OI
TM
catheter.
...Methods
LI and generator impedance drops (ΔLI and ΔGI) were evaluated in excised porcine hearts (
N
= 16) during RF applications at a range of powers (30 and 50 W), contact forces (5–40 g), and durations (10–180 s) using perpendicular or parallel catheter orientation. Additionally, temporal LI changes were assessed.
Results
Of the 240 lesions without steam pops (92.3%), ΔLI showed better correlations with lesion surface area (
ρ
= 0.55 vs 0.36,
P
= 0.004), maximum depth (
ρ
= 0.53 vs 0.14,
P
< 0.001), and lesion volume (
ρ
= 0.64 vs 0.23,
P
< 0.001) than ΔGI. Furthermore, %LI-drop (ΔLI/initial LI) demonstrated stronger correlations with lesion surface area (
ρ
= 0.60 vs 0.55,
P
< 0.001), maximum depth (
ρ
= 0.57 vs 0.53,
P
< 0.001), and volume (
ρ
= 0.69 vs 0.64,
P
< 0.001) than ΔLI. Parallel catheter orientation improved correlation of ΔLI with lesion surface area (
ρ
= 0.63 vs 0.40,
P
= 0.015) and depth (
ρ
= 0.68 vs 0.45,
P
= 0.008) and created a larger surface lesion (36.329.2–42.7 mm
2
vs 28.821.6–34.2 mm
2
,
P
< 0.001) than the perpendicular. LI of the lesions significantly differed between baseline, immediately after RF, and 5 min after (
P
< 0.01). LI reaching plateau, larger initial LI, ΔLI, and %LI-drop, and larger RF power and longer duration were observed in pop lesions (
P
< 0.05).
Conclusions
%LI-drop demonstrated a better correlation with lesion size than ΔLI. LI may be used as an additional parameter to predict lesion size and steam pops. Temporal variation and catheter orientation should be considered to interpret LI.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Background: The relationship between major adverse cardiac events (MACE) and serum polyunsaturated fatty acid (PUFA) parameters has not been well documented in patients who have undergone ...percutaneous coronary intervention (PCI). The aim of the present study was to investigate this relationship. Methods and Results: A total of 284 consecutive patients who underwent elective PCI were enrolled and stratified according to median serum levels of n-6 PUFAs (arachidonic acid AA), n-3 PUFAs (eicosapentaenoic acid EPA and docosahexaenoic acid DHA), and serum EPA/AA and DHA/AA ratios. The relationship between these PUFA parameters and the incidence of MACE including cardiac death, acute coronary syndrome, PCI for de novo lesions, and coronary artery bypass grafting, was analyzed. Multivariate analysis showed that among the PUFA parameters, only a high serum EPA/AA ratio was significantly associated with a low incidence of MACE in all the models tested (model A, without adjusted variables: hazard ratio HR, 0.52; 95% confidence interval CI: 0.27-0.99, P=0.048; model B, adjusted for age and diabetes: HR, 0.51; 95%CI: 0.26-0.98, P=0.043; model C, adjusted for age, sex, diabetes, hypertension, smoking, and low-density lipoprotein cholesterol: HR, 0.49; 95%CI: 0.25-0.94, P=0.033). Conclusions: The incidence of MACE in patients who have undergone PCI is significantly associated with serum EPA/AA ratio. (Circ J 2012; 76: 423-429)
Background:The SALUTE trial was a prospective, multicenter, single-arm trial to confirm the safety and efficacy of the WATCHMAN left atrial appendage closure (LAAC) device for stroke prevention in ...patients with nonvalvular atrial fibrillation (NVAF) in Japan.Methods and Results:A total of 54 subjects (including 12 roll-in subjects) with a WATCHMAN implant procedure were followed in 10 investigational centers. Follow-up visits were performed up to 2 years post-implant. The baseline CHA2DS2-VASc score was 3.6±1.6 and the baseline HAS-BLED score was 3.0±1.1. All 42 subjects in the intention to treat (ITT) cohort underwent successful implantation of the LAAC device without any serious complications, achieving the prespecified performance goal. The effective LAAC rate was maintained at 100% from 45 days to 12 months post-implant, achieving the prespecified performance goal. During follow-up, 1 subject died of heart failure, and 3 had ischemic strokes, but there were no cases of hemorrhagic stroke or systemic embolism. All events were adjudicated as unrelated to the WATCHMAN device/procedure by the independent Clinical Events Committee. All 3 ischemic strokes were classified as nondisabling based on no change in the modified Rankin scale score.Conclusions:Final results of the SALUTE trial demonstrated that the WATCHMAN LAAC device is an effective and safe alternative nonpharmacological therapy for stroke risk reduction in Japanese NVAF patients who are not optimal candidates for lifelong anticoagulation. (Trial Registration: clinicaltrials.gov Identifier NCT 03033134)
Background
Although ablation energy (AE) and force-time integral (FTI) are well-known active predictors of lesion characteristics, these parameters do not reflect passive tissue reactions during ...ablation, which may instead be represented by drops in local impedance (LI). This study aimed to investigate if additional LI data improves predicting lesion characteristics and steam pops.
Methods
RF applications at a range of powers (30 W, 40 W, and 50 W), contact forces (8 g, 15 g, 25 g, and 35 g), and durations (10–180 s) using perpendicular/parallel catheter orientations were performed in excised porcine hearts (
N
= 30). The correlation between AE, FTI, and lesion characteristics was examined, and the impact of LI (%LI drop (%LID) defined by the ΔLI divided by the initial LI) was additionally assessed.
Results
Three hundred seventy-five lesions without steam pops were examined. Ablation energy (W × s) and FTI (g × s) showed a positive correlation with lesion depth (
ρ
= 0.824:
P
< 0.0001 and
ρ
= 0.708:
P
< 0.0001), surface area (
ρ
= 0.507:
P
< 0.0001 and
ρ
= 0.562:
P
< 0.0001), and volume (
ρ
= 0.807:
P
< 0.0001 and
ρ
= 0.685:
P
< 0.0001). %LID also showed a positive correlation individually with lesion depth (
ρ
= 0.643:
P
< 0.0001), surface area (
ρ
= 0.547:
P
< 0.0001), and volume (
ρ
= 0.733:
P
< 0.0001). However, the combined indices of AE × %LID (AE multiplied by %LID) and FTI × %LID (FTI multiplied by %LID) provided significantly stronger correlation with lesion depth (
ρ
= 0.834:
P
< 0.0001 and
ρ
= 0.809:
P
< 0.0001), surface area (
ρ
= 0.529:
P
< 0.0001 and
ρ
= 0.656:
P
< 0.0001), and volume (
ρ
= 0.864:
P
< 0.0001 and
ρ
= 0.838:
P
< 0.0001). This tendency was observed regardless of the catheter placement (parallel/perpendicular). AE (
P
= 0.02) and %LID (
P
= 0.002) independently remained as significant predictors to predict steam pops (
N
= 27). However, the AE × %LID did not increase the predictive power of steam pops compared to the AE alone.
Conclusion
LI, when combined with conventional parameters (AE and FTI), may provide stronger correlation with lesion characteristics.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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