Background:Atrial fibrillation (AF) is a common cardiac arrhythmia, associated with increased cardiovascular morbidity and mortality including thromboembolic events. The aims of this study were to ...assess the prevalence of left atrial appendage (LAA) thrombi in Japanese non-valvular atrial fibrillation (NVAF) patients undergoing preprocedural transesophageal echocardiography (TEE) during anticoagulation therapy, and to compare the efficacy of warfarin and direct oral anticoagulants (DOAC).Methods and Results:This retrospective study reviewed records of 559 consecutive NVAF patients (445 men; age, 62±11 years) undergoing preprocedural TEE following at least 3 weeks of anticoagulation therapy. Of these, 275 patients had non-paroxysmal AF (49%). LAA thrombus was observed in 15 patients (2.7%). The prevalence of LAA thrombi was similar between the DOAC group (2.6%) and the warfarin group (2.8%, P=0.86). No patients with CHA2DS2-VASc score=0, or paroxysmal AF without prior stroke or transient ischemic attack, had LAA thrombi. On univariate analysis, non-paroxysmal AF, structural heart disease, antiplatelet therapy, larger left atrium, higher brain natriuretic peptide (BNP), reduced LAA flow, and higher CHA2DS2-VASc score were all associated with LAA thrombi. On multivariate analysis, BNP ≥173 pg/mL remained the only independent predictor of LAA thrombi.Conclusions:LAA thrombi were found in 2.7% of Japanese NVAF patients scheduled for procedures despite ongoing oral anticoagulation therapy. Incidence of thrombi was similar for patients on DOAC and on warfarin.
Background: For lesion size prediction, each input parameter, including ablation energy (AE), and output parameter, such as impedance, is individually used. We hypothesize that using both parameters ...simultaneously may be more optimal.Methods and Results: Radiofrequency applications at a range of power (30–50 W), contact force (10 g and 20 g), duration (10–60 s), and catheter orientation with normal saline (NS)- or half-normal saline (HNS)-irrigation were performed in excised porcine hearts. The correlations, with lesion size of AE, absolute impedance drop (∆Imp-drop), relative impedance drop (%Imp-drop), and AE*%Imp-drop were examined. Lesion size was analyzed in 283 of 288 lesions (NS-irrigation, n=142; HNS-irrigation, n=141) without steam pops. AE*%Imp-drop consistently showed the strongest correlations with lesion maximum depth (NS-irrigation, ρ=0.91; HNS-irrigation, ρ=0.94), surface area (NS-irrigation, ρ=0.87; HNS-irrigation, ρ=0.86), and volume (NS-irrigation, ρ=0.94; HNS-irrigation, ρ=0.94) compared with the other parameters. Moreover, compared with AE alone, AE*%Imp-drop significantly improved the strength of correlation with lesion maximum depth (AE vs. AE*%Imp-drop, ρ=0.83 vs. 0.91, P<0.01), surface area (ρ=0.73 vs. 0.87, P<0.01), and volume (ρ=0.84 vs. 0.94, P<0.01) with NS-irrigation. This tendency was also observed with HNS-irrigation. Parallel catheter orientation showed a better correlation with lesion depth and volume using ∆Imp-drop, %Imp-drop, and AE*%Imp-drop than perpendicular orientation.Conclusions: The combination of input and output parameters is more optimal than each single parameter for lesion prediction.
Introduction
The left atrial (LA) posterior wall (LAPW) has been targeted to improve the clinical outcomes in patients with persistent atrial fibrillation (PersAF). This study aimed to investigate ...the feasibility, safety, and clinical implications of cryoballoon (CB) applications on the LAPW to accomplish electrical isolation (EI) of the LAPW with CB.
Methods
A total of 100 patients (males, 84; mean age, 64 ± 10 years) with PersAF were enrolled. The first 50 patients underwent only pulmonary vein isolation (PVI) (PVI‐only group) and the remaining 50 patients underwent PVI and EI of the LAPW with CB (EI‐LAPW group).
Results
One‐year sinus rhythm maintenance probability was significantly higher in the EI‐LAPW group than in PVI‐only group (80.0% vs 55.1%, P = 0.01). The success rate of constructing an LA roof block line (LA‐RB), bottom block line, and EI of the LAPW was 92%, 60%, and 58%, respectively. The nadir CB temperature (−45°C ± 4°C vs −39°C ± 5°C,
P = 0.005) and anatomical angle of the left atrial roof (106°C ± 30°C vs 144°C ± 17°C,
P < 0.001) significantly predicted the successful LA‐RB construction. The left ventricular ejection fraction was significantly higher in unsuccessful cases than in successful cases of an EI of the LAPW (64% ± 8% vs 58% ± 11%,
P = 0.041). Even though the EI of the LAPW was unsuccessful, CB freezing in LAPW significantly debulked the nonscar area (≥0.1 mV) in LAPW (18.1 ± 5.6 vs 2.2 ± 3.1 cm
2,
P < 0.001) and provided the equivalent 1‐year outcome of successful cases (79.3% vs 81.0%,
P = 0.90).
Conclusion
The combination of PVI and EI of the LAPW with CB provided better clinical outcomes than conventional PVI procedure for patients with PersAF.
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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
Manganese (Mn) is a major element in various aqueous and soil environments that is sometimes highly concentrated in mine water and other mineral processing wastewater. In this study, we investigated ...Mn removal from alkaline mine water (pH > 9) with an Mn-coated silica sand packed into a pilot-scale column reactor and examined the specific reaction mechanism using X-ray absorption near-edge structure (XANES) analysis and geochemical kinetic modeling. The kinetic effect of dissolved Mn(II) removal by birnessite (δ-Mn(IV)O2) at pH 6 and 8 was evaluated at different Mn(II)/Mn(IV) molar ratios of 0.1–10. Our results confirmed the positive effect of the presence of δ-MnO2 on the short-term removal (60 min) of dissolved Mn. XANES analysis results revealed that δ-MnO2 was more abundant than Mn(III)OOH in the reactor, which may have accumulated during a long-term reaction (4 months) after the reactor was turned on. A gradual decrease in dissolved Mn(II) concentration with depth was observed in the reactor, and comparison with the kinetic modeling result confirmed that δ-MnO2 interaction was the dominant Mn removal mechanism. Our results show that δ-MnO2 contents could play a significant role in controlling Mn removability from mine water in the reactor.
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CEKLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Background/Objectives
The QDOT‐MICRO™ catheter allows very high‐power and short‐duration (vHPSD) ablation. This study aimed to investigate lesion characteristics using different ablation settings.
...Methods
Radiofrequency applications (90 W/4 s, temperature‐control mode with 55°C or 60°C target) were performed in excised porcine myocardium using three different approaches: single (SA), double nonrepetitive (DNRA), and double repetitive applications (DRA). Applications were performed with an interval of 1 min for DNRA, and without interval for DRA.
Results
A total of 480 lesions were analyzed. Lesion depth and volume were largest for DRA followed by DNRA and SA regardless of catheter direction (depth: 3.8 vs. 3.3 vs. 2.6 mm, p < .001 for all comparisons; volume: 176.6 vs. 145.1 vs. 97.0 mm3, p < .001 for all comparisons). Surface area was significantly larger for DRA than for SA (45.1 vs. 38.3 mm2, p < .001) and larger for DNRA than for SA (44.5 vs. 38.3 mm2, p < .001), but was similar between DRA and DNRA (45.1 vs. 44.5 mm2, p = .54). Steam‐pops more frequently occurred for DRA than for SA (15.6% vs. 4.4%, p = .004) and DNRA (15.6% vs. 6.9%, p = .061), but the incidence was similar between SA and DNRA (4.4% vs. 6.9%, p = 1). Although surface area and lesion volume were larger in lesions with steam‐pops than without steam‐pops (46.5 vs. 38.1 mm2, p = .018 and 128.3 vs. 96.8 mm3, p = .068, respectively), lesions were not deeper (pop(+): 2.5 mm vs. pop(−): 2.6 mm, p = .75).
Conclusions
DNRA produces larger lesions than SA without increasing the risk of steam‐pops. DRA produces the largest lesions among the three groups, but with an increased risk of steam‐pops. Even with steam‐pops, lesions do not become deeper in vHPSD ablation.
(Top) Although lesion depth of single radiofrequency applications is small, double RF application with 1 min ‘rest’ interval may produce deeper lesions without increasing steam‐pops in very high‐power and short‐duration (vHPSD) ablation. (Bottom) Lesion depth does not increase with steam‐pops, suggesting a degree of safety for vHPSD 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
•Continuous direct oral anticoagulant (DOAC) administration throughout atrial fibrillation ablation is still controversial.•We compared interrupted DOACs and uninterrupted dabigatran throughout the ...ablation.•Uninterrupted dabigatran significantly reduced risk of silent stroke.•There were no significant differences in bleeding events.
Catheter manipulation in the left-sided heart is known as a risk for cerebral embolisms (CEs). However, anticoagulation therapy is terminated before catheter ablation (CA) of atrial fibrillation (AF) concerning adverse bleeding events. Little is known whether uninterrupted direct oral anticoagulants (DOACs) during perioperative period of CA could render the ablation procedure safer and reduce the incidence of CEs compared to interrupted DOACs. The aim of this study was to investigate the safety and usefulness of uninterrupted dabigatran during the periprocedural period for CA of AF.
We included 333 patients with paroxysmal AF undergoing cryoballoon CA (CBA). They were prospectively divided into 2 groups based on whether DOACs were interrupted on the day of the CA (Group A, n=228) or dabigatran was not interrupted throughout perioperative period (Group B, n=105) in a non-randomized fashion. When the Group B patients had taken other DOACs rather than dabigatran before assignment, we changed those DOACs to dabigatran. Brain magnetic resonance imaging (MRI) was undertaken on the following day of the CA. Serious bleeding event cases were excluded from the study.
The baseline characteristics including the CHADs2 score did not exhibit any significant differences between the groups. The brain MRI revealed an acute CEs in 82 patients, and was significantly higher in Group A than B (29% vs. 13%, respectively, p<0.01). There were no significant differences regarding the bleeding events (7% vs. 4%, respectively, p=0.62).
Uninterrupted dabigatran therapy during the CBA of paroxysmal AF could significantly reduce the incidence of CEs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Purpose
Rapid ventricular pacing (RVP) was reported to improve the cooling effects of the cryoballoon (CB). The aim of this study was to investigate the safety and efficacy of RVP for left atrial ...posterior wall isolation (PWI) by the CB.
Methods
One hundred consecutive patients (males 80, mean age 63 ± 10 years) with persistent atrial fibrillation underwent left atrial roof (LA-RB) and bottom block line (LA-BB) creation by CB to achieve PWI. Patients were randomized into two groups according to whether they underwent PWI with (RVP group,
n
= 50) or without RVP (control group,
n
= 50).
Results
The nadir CB temperature (NCT) during the LA-RB and LA-BB creation was significantly lower in the RVP group than control group (LA-RB − 45.7 °C and − 43.9 °C,
p
< 0.001, and LA-BB − 42.4 °C and − 40.0 °C,
p
< 0.001). The success rate of the LA-RB creation was significantly higher in the RVP group than the control group (98% vs. 88%,
p
= 0.039), however, there were no significant differences regarding the LA-BB creation (66% vs. 52%,
p
= 0.15) and PWI (66% vs. 50%,
p
= 0.1) between the two groups. The PWI success rate did not differ whether CB freezing was prematurely terminated due to an excessive luminal esophageal temperature (LET) drop in the RVP group (65.8% vs. 66.7%, respectively,
p
= 0.96).
Conclusions
RVP significantly decreased the NCT during the CB application resulting in the significant improvement of success rate of the LA-RB. The advantage of RVP in terms of the accomplishing PWI was not affected even when the CB freezing was prematurely terminated due to an excessive LET drop.
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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 FlexAbility™ SE catheter has a laser-cut 8Fr 4-mm flexible tip irrigated through laser-cut kerfs with a thermocouple 0.3 mm from the distal end. The TactiCath™ SE catheter has an 8Fr ...3.5-mm tip and 6-irrigation port with a thermocouple 2.67 mm proximal to the tip. We investigated the impact of these differences on the efficacy and safety of radiofrequency (RF) applications.
Methods
RF applications at a range of powers (20 W, 30 W, and 40 W), contact forces (5 g, 15 g, and 25 g), and durations (10–60 s) using perpendicular/parallel catheter orientation were performed in excised porcine hearts. Lesion characteristics and incidence of steam pops were compared.
Results
A total of 540 lesions were examined. The FlexAbility™ SE catheter produced smaller lesion depths (4.0 mm vs. 4.4 mm,
p
= 0.014 at 20 W; 4.6 mm vs. 5.6 mm,
p
= 0.015 at 30 W), surface areas (22.7mm
2
vs. 29.2mm
2
at 20 W,
p
= 0.005; 23.2mm
2
vs. 28.7mm
2
,
p
= 0.009 at 30 W), and volumes (126.1mm
3
vs. 175.1mm
3
,
p
= 0.018 at 20 W; 183.2mm
3
vs. 304.3mm
3
,
p
= 0.002 at 30 W) with perpendicular catheter placement. However, no differences were observed with parallel catheter placement. Steam-pops were significantly less frequently observed with the FlexAbility™ SE catheter (4% vs. 22%,
p
< 0.001) irrespective of catheter direction to the tissue. Multivariate analysis showed that use of the TactiCath™ SE catheter, power ≥ 40 W, contact force ≥ 25 g, RF duration > 30 s, parallel angle, and impedance drop ≥ 20Ω were significantly associated with occurrence of steam-pops.
Conclusions
The FlexAbility™ SE catheter reduced the risk of steam-pops but produced smaller lesions with perpendicular catheter placement compared to the TactiCath™ SE catheter.
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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
Purpose
The size of the distal electrode and the method of measuring local impedance (LI) are different between the IntellaNav MiFi-OI™ (MiFi-OI) and IntellaNav STABLE POINT™ (SP) catheters. We ...investigated the impact of these differences on LI, efficacy, and safety of radiofrequency (RF) applications.
Methods
RF applications at a range of powers (30 W, 40 W, and 50 W), contact forces (10 g and 20 g), and durations (10–120 s) were performed in excised porcine hearts (
N
= 48). LI variation was defined by δLI-drop (= initial LI − post-RF LI) and %LI-drop (= δLI-drop/initial LI) × 100, and the relationship between lesion characteristics and LI variation was compared.
Results
A total of 576 lesions were examined. Although absolute δLI-drop during RF applications was significantly larger for the SP than MiFi-OI catheter (4731–65ohm for SP vs 3724–51ohm for MiFi-OI,
p
< 0.0001), %LI-drop was similar (23.3 15.5–30.6% in SP vs 24.917.3–32.5% in MiFi-OI,
p
= 0.10). Although lesions produced by both catheters were similarly correlated with LI variation, the SP catheter produced generally larger lesions (depth; 5.0 3.7–6.1mm vs 4.7 3.3–6.0mm,
p
= 0.06; surface areas, 46.9 36.8–58.8mm
2
vs 44.7 34.3–55.5mm
2
,
p
= 0.02; volume, 321 165–533mm
3
vs 265141–471mm
3
,
p
= 0.02). Steam pops were similarly observed with both catheters. In both catheters, %LI-drop was superior to δLI-drop in correlation to lesion size (
p
< 0.0001) and in predicting steam pops (
p
< 0.01).
Conclusions
Although no difference in safety profile is observed between MiFi-OI and SP catheters, the SP catheter produces larger lesions. %LI-drop is superior to δLI-drop in correlation to lesion size and in predicting steam pops as well as in normalizing the difference between catheters.
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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
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