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INTRODUCTION Gastric hypomotility (GH) is a major complication of atrial fibrillation (AF) ablation. We aimed to clarify whether additional cryoballoon ablation (CBA) of the left atrial (LA) roof is associated with GH. METHODS AND RESULTS This study included 54 patients with non-paroxysmal AF who underwent CBA for pulmonary vein isolation and of the LA roof line. GH was defined according to the results of esophagogastroscopy performed 2 days after ablation. GH was observed in 10 patients. There were significant differences in LA diameter (LAD), right inferior pulmonary vein (RIPV) diameter, and the height of the LA roof from the point where the LA posterior wall and esophagus make contact between patients with (GH+) and without GH (GH-) (LAD: 41.0 [36.3-41.8] mm vs. 46.5 [42.8-50.0] mm, p

Although cryoballoon ablation of atrial fibrillation (AF) has been traditionally guided by pulmonary vein (PV) occlusion, there is evidence and growing interest in performing segmental, non-occlusive cryoballoon ablation to target not only large/common PVs, but extra-PV structures such as the left atrial (LA) roof and posterior wall in conjunction with PV isolation. To date, a number of studies have demonstrated improved clinical efficacy associated with non-occlusive cryoballoon ablation of the LA roof and posterior wall in addition to PV isolation, particularly in patients with persistent AF. Not only the cryoballoon can be utilized for targeting extra-PV structures through segmental, non-occlusive ablation, but the large size and durability of cryolesions coupled with the enhanced stability afforded through cryoadhesion render the cryoballoon an effective tool for such an approach. This manuscript reviews the rationale and the practical approach to segmental, non-occlusive cryoballoon ablation of large/common PV antra and the LA roof and posterior wall.

Atrial fibrillation (AF) mostly originates from the pulmonary vein (PV). As a result, 70%−90% of AF patients can be successfully treated with extensive PV isolation. However, the precise identification of the site of trigger in the remaining 10%–30% with non-PV foci1, 2, 3 is often difficult. Especially in cases that require multiple electrical cardioversions because of immediate recurrence of AF after cardioversion, the mapping of origins becomes more difficult. In this case, a prominent Eustachian ridge was demonstrated as a source of AF trigger by high-density grid mapping catheter (Advisor™ HD Grid Catheter; Abbott Medical, Minneapolis, MN).

Second-generation cryoballoon (CB) ablation is effective in achieving pulmonary vein (PV) isolation (PVI) in atrial fibrillation (AF) patients. The "crosstalk" (CST) phenomenon has been reported to reduce unnecessary applications during CB ablation. Nevertheless, it is unclear under what conditions the CST phenomenon occurs.To seek the predictors of the CST phenomenon during CB-guided PVI, CST phenomenon in achieving ipsilateral superior PVI during inferior PV ablation was analyzed in AF patients who underwent de novo ablation using CB. CB occlusion status and nadir balloon temperature (NT) were compared in these patients, and all ablated superior PVs were categorized into three groups according to the necessity of the touch up ablation and effectiveness of the phenomenon.Of 1082 superior PVs, 16, 40, and 1026 were classified into the CST success, CST failure, and control groups (unnecessary CST), respectively. The proportion of superior PVs ablated with complete occlusion using the CB was significantly higher in the CST success group than in the other two groups. The proportion of superior PVs ablated with NT ≤ -46°C was higher in the CST success group than in the CST failure group. The CST phenomenon was always observed if CB ablation of the superior PVs was performed with both complete occlusion and NT ≤ -46°C and was almost always ineffective if it did not meet these two criteria (sensitivity, 100%; specificity, 93%).Successful CST ablation was highly predicted if complete PV occlusion and NT ≤ -46°C during CB ablation of the superior PVs were achieved.

Radiofrequency and cryoballoon applications around the pulmonary veins (PVs) could provoke a vagal reflex (VR) by modulating the intrinsic cardiac autonomic nervous system (ICANS).This study aimed to investigate the incidence, timing, and clinical impact of a VR provoked by a laser balloon application for a PV isolation (PVI).A total of 92 consecutive paroxysmal atrial fibrillation (PAF) patients underwent a laser balloon PVI of PAF. Acute changes in the heart rate and blood pressure were recorded. The heart rate variability (HRV) was tested by Holter ECGs before and at three months following the ablation. Three hundred forty-five out of 363 PVs were successfully isolated (97%) with laser balloon applications. A VR such as sinus bradycardia (26.1%), transient sinus arrest (9.8%), transient atrioventricular block (1.1%), or a blood pressure reduction (8.7%) was observed during the laser balloon applications for the PVI. The follow-up ended at 12 months. The HRV attenuation was comparable before and at three months after the ablation procedure between that with and without a VR (P = 0.14). The PAF recurrence rate was also comparable between the two groups (P = 0.882).The laser balloon PVI often provoked a VR, however, the modulation of the ICANS was temporary and for up to three months as measured by the HRV changes after the ablation, and the freedom from any atrial fibrillation recurrence was comparable regardless of the occurrence of a VR.

Introduction: Pulmonary vein (PV) isolation (PVI) with a balloon-based visually guided laser ablation (VGLA) is a useful tool for treating atrial fibrillation (AF), however, phrenic nerve injury (PNI) is an important complication. We investigated the predictors of developing PNI during VGLA. Methods and Results: This study included 130 consecutive patients who underwent an initial VGLA of non-valvular paroxysmal AF. During the ablation of the right-sided pulmonary veins, continuous and stable right phrenic nerve pacing was performed, and the compound motor action potentials (CMAPs) were recorded. Twenty patients developed PNI during the PVI. The patients who suffered from PNI had a significantly larger right superior PV (RSPV) ostium area (284.7 ± 47.0 mm2 vs. 233.1 ± 46.4 mm2, P < 0.01) than that of the other patients. Receiver operating characteristic analyses revealed that the area under the curve of the RSPV ostial area was 0.79 (95% confidence interval: 0.69-0.90) with an optimal cut-off point of 238.0 mm2 (sensitivity: 0.58, specificity: 0.95). In the multivariate analyses, large RSPV ostial area (HR 1.02, 95% confidence interval: 1.01-1.03, P < 0.01) and small balloon size (HR 0.72, 95% confidence interval: 0.53-0.98, P = 0.03) were independent risk factors for PNI. PNI remained in 13 patients after the procedure, but 12 of those patients recovered from PNI during the follow-up period. Conclusion: The incidence of PNI during the VGLA was relatively high, but the PNI improved in the majority of cases. During the VGLA, a large RSPV and small balloon size were predictors of PNI.

Objectives The aim of this multicenter, randomized, single-blind study was to prospectively evaluate the short-and long-term outcomes of pulmonary vein isolation (PVI) versus PVI with concomitant left atrial posterior wall isolation (PWI) using the cryoballoon in patients with symptomatic persistent/long-standing persistent atrial fibrillation (P/LSP-AF). Background Some studies have suggested a clinical benefit associated with PVI+PWI in patients with P/LSP-AF. However, there are limited safety and efficacy data on this approach using cryoballoon ablation. Methods The immediate and long-term outcomes in patients with P/LSP-AF randomized to PVI (n = 55) versus PVI+PWI (n = 55) using the cryoballoon were prospectively examined. Results Baseline characteristics were similar. PVI was achieved in all patients (21 ± 11 min). PWI was attained using 23 ± 8 min of cryoablation. Adjunct radiofrequency ablation was required in 4 of 110 patients (7.3%) to complete PVI (3 ± 2 min) and in 25 of 55 patients (45.5%) to complete PWI (4 ± 6 min). Although left atrial dwell time (113 ± 31 min vs. 75 ± 32 min; p Conclusions In patients with P/LSP-AF, PVI+PWI using the cryoballoon is associated with a significant reduction in atrial fibrillation recurrence, but similar safety, as compared with PVI alone.

A 75-year-old man was admitted for repeat ablation of atrial fibrillation. At 30 min after infusion of 3.5 ml of ethanol into the vein of Marshall, inferior ST-segment elevation with coronary arterial vasospasm was observed. This is the first report of coronary vasospasm after chemical ablation of the vein of Marshall. (Level of Difficulty: Intermediate.), Graphical abstract, A 75-year-old man was admitted for repeat ablation of atrial fibrillation. At 30 min after infusion of 3.5 ml of ethanol into the vein of Marshall, inferior…

Key Clinical Message Ventricular tachycardia (VT) arising from the left ventricular summit is very tough to treat endocardially and epicardially due to the distance from the VT origin and close proximity to the coronary arteries, respectively. Ethanol infusions into coronary veins feeding VT origins were able to safely abolish this type of VT., Ventricular tachycardia (VT) arising from the left ventricular summit is very tough to treat endocardially and epicardially due to the distance from the VT origin and close proximity to the coronary arteries, respectively. Ethanol infusions into coronary veins feeding VT origins were able to safely abolish this type of VT.

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, p0.01). 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.

Cryoenergy has been demonstrated to be a safe alternative to radiofrequency ablation for catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). This study aimed to evaluate the safety and efficacy of cryoablation in patients with AVNRT. A multicenter retrospective study was performed. Two hundred eighty-three consecutive patients with AVNRT underwent cryoablation. Cryomapping at − 30 °C and − 80 °C was performed to predict cryoablation outcome and ascertain antegrade conduction. Cryoenergy was delivered subsequently at the same spot (cryoablation at − 80 °C) for 240 s. Ablation procedure was acutely successful in 281 out of 283 patients (99.3%). Of note, 22 patients (10.1%) had transient AV block during the cryoablation, but no injurious effects on AV conduction were provoked during cryomapping. During a follow-up period of 367 ± 35 days, the recurrence rate was 3.9% (11 out of 281). There were no significant differences among the patients with a complete elimination of slow pathway conduction, AH jump without an echo beat, and AH jump with a single echo beat, in terms of the long-term recurrence of AVNRT. Cryoablation of AVNRT appears to be effective both acutely and during the long-term with a minimal risk of unwanted injuries to the conduction system. It seems to be important to monitor the antegrade conduction during cryoenergy applications, even when cryomapping demonstrates a safe location for cryoablation. The recurrence rate of AVNRT did not differ according to the properties of the residual slow pathway conduction.

Background The left atrial myocardium (LAM) and coronary sinus (CS) musculature (CSM) generate atrial electrograms recorded inside the CS (AECSs). The vein of Marshall (VOM) courses the mitral isthmus (MI), and ethanol infusion into the VOM (EI-VOM) is useful to ablate it. However, its detailed effect on the MI, which contains the LAM, CSM, and those connections, is unknown. Objective The purpose of this study was to investigate the impact of EI-VOM on the MI by assessing the AECS. Methods Eighty-four consecutive patients with atrial fibrillation undergoing MI ablation with successful EI-VOM were included. After EI-VOM, radiofrequency (RF) catheter touchup ablation was performed at MI gap sites or inside the CS (RFCS), as needed, to achieve bidirectional conduction block. Ablation effects on AECSs were evaluated during the MI ablation procedure. Results AECSs demonstrated double potentials consisting of low-amplitude LAM components and high-amplitude CSM components in 31 patients (37%). Of those patients, 21 had a distal-to-proximal activation sequence of the LAM along with a proximal-to-distal activation sequence of the CSM during left atrial appendage pacing, suggesting CSM isolation from the LAM due to electrical LAM–CSM disconnection. Only 2 of the 21 patients required RFCS. The remaining 10 patients with distal-to-proximal activation in both CSM and LAM, suggesting incomplete CSM isolation and persistent LAM–CSM conduction, required RFCS. Overall, combined EI-VOM with RF created bidirectional conduction block at the MI in 78 patients (93%). Conclusion EI-VOM can ablate the LAM and myocardial connections between the LAM and CSM. Careful assessment of AECSs can predict a requirement for RFCS.

1 Current status of non‐pharmacotherapies in Japan Pacemaker treatment for bradyarrhythmia was first approved for national health insurance coverage in Japan in 1974, and its use rapidly became widespread thereafter. Approximately 40 years later, in 2017, the number of patients treated with this technology has increased to 60 137 (41 895 new cases and approximately 18 242 replacements). 5 Capsule‐shaped leadless pacemaker also became available in 2016, and this technology is being established as a new option. Non‐pharmacological treatment of tachy‐arrhythmia began in 1969 from when Will C. Sealy performed surgery in patients with Wolff‐Parkinson‐White (WPW) syndrome (Figure 1). Since then, the application of surgical treatment has expanded to conditions such as ventricular tachycardia (VT) and atrial fibrillation (AF), and surgery has been the pioneer of radical therapy for tachyarrhythmias. At the present time, many surgical methods have been replaced by catheter ablation; however, surgical treatment still remains an indispensable option for patients with a tachycardia resistant to other medical treatments. Open in a separate window FIGURE 1 History of non‐pharmacotherapy of cardiac arrhythmia

Background This study aimed to clarify the clinical outcomes of cryoballoon ablation of the left atrial (LA) posterior wall (LAPW), including the LA roof, in patients with non‐paroxysmal atrial fibrillation (AF). Methods We analyzed the outcomes of 284 patients with non‐paroxysmal AF, of whom 210 underwent the cryoballoon ablation of the LAPW, including the LA roof, in addition to pulmonary vein isolation with a cryoballoon. Results Complete conduction block at the LA roof was obtained in 95.7% (201/210) of patients, and LAPW was isolated in 83.3% (130/156) of patients. Over 372 (range, 208–477) days of follow‐up, atrial arrhythmia recurrence was observed in 84 (29.6%) patients, and atrial tachycardia (AT) recurrence accounted for 27.4% of cases. The prevalence of LA roof cryoballoon ablation was significantly higher in patients without recurrence than in those with recurrence (78.6% vs. 63.1%, respectively; p = .01), especially those with persistent AF recurrence (77.0% vs. 55.0%, p = .01). No significant difference was found in the prevalence of AT recurrence between patients who had undergone additional LAPW ablation and those who had not. Durable LA roof lesions were confirmed in 29 (72.5%) of 40 patients who underwent redo ablation. Conclusions Cryoballoon ablation of the LAPW leads to a sufficient acute success rate of complete conduction block and durable lesions of the LA roof without increasing AT recurrence risk. The prevalence of persistent AF recurrence decreases after additional cryoballoon ablation of the LAPW in patients with non‐paroxysmal AF., Cryoballoon ablation of the left atrial roof or the left atrial posterior wall could be performed safely. It brings sufficient efficacy in terms of reducing the recurrence as a persistent form of atrial fibrillation.

Background: Contrast computed tomography (CT) is a useful tool for the detection of intracardiac thrombi. We aimed to assess the accuracy of the late-phase prone-position contrast CT (late-pCT) for thrombus detection in patients with persistent or long-standing persistent atrial fibrillation (AF). Methods: Early and late-phase pCT were performed in 300 patients with persistent or long-standing AF. If late-pCT did not show an intracardiac contrast defect (CD), catheter ablation (CA) was performed. Immediately prior to CA, intracardiac echocardiography (ICE) from the left atrium was performed to confirm thrombus absence and the estimation of the blood velocity of the left atrial appendage (LAA). For patients with CDs on late-pCT, CA performance was delayed, and late-pCT was performed again after several months following oral anticoagulant alterations or dosage increases. Results: Of the 40 patients who exhibited CDs in the early phase of pCT, six showed persistent CDs on late-pCT. In the remaining 294 patients without CDs on late-pCT, the absence of a thrombus was confirmed by ICE during CA. In all six patients with CD-positivity on late-pCT, the CDs vanished under the same CT conditions after subsequent anticoagulation therapy, and CA was successfully performed. Furthermore, the presence of residual contrast medium in the LAA on late-pCT suggested a decreased blood velocity in the LAA (≤ 15 cm/s) (sensitivity = 0.900 and specificity = 0.621). Conclusions: Late-pCT is a valuable tool for the assessment of intracardiac thrombi and LAA dysfunction in patients with persistent or long-standing persistent AF before CA.

Background Biatrial tachycardia (BiAT) is a rare form of atrial macro-re-entrant tachycardia. Precise identification of interatrial connections and circuits of the BiAT is difficult. And incomplete understanding of the re-entrant circuit may lead to unnecessary ablation, thus increasing the risk of complications. Case summary A 69-year-old man with a history of mitral valve plasty for mitral regurgitation due to mitral valve prolapse was admitted for persistent atrial tachycardia. Electrophysiological examination using the CARTO mapping system was performed. A coherent map revealed an atrial tachycardia with a cycle length of 304 ms and a re-entrant circuit involving the left atrial septum and right atrial septum, while a ripple map suggested an epicardial interatrial connection between the right atrium and left atrium. Radiofrequency ablation on the epicardial connection successfully terminated BiAT without complications. Discussion In BiAT using both atrial septum as a re-entrant circuit, an interatrial connection or an atrial septum can be the target site for ablation. However, septal ablation can be challenging because of the risk of atrioventricular block or interatrial conduction delay, and minimal line or point ablation is needed. Coherent and ripple mapping can accurately determine the re-entrant circuit and interatrial connection of BiAT and reduce complication risks by terminating the atrial tachycardia with minimal ablation.

Background Ablation using radiofrequency energy has to be carefully performed when the arrhythmia substrate is located in close proximity to the atrioventricular (AV) node due to the risk of inadvertent permanent AV block. The aim of this study was to evaluate the efficacy and safety of catheter-based cryo-therapy for septal accessory pathways (APs). Methods A total of eleven patients (median = 56.3 years, range 13–74 years) with septal APs underwent cryoablation. Ice-mapping was performed during sinus rhythm and an AV reciprocating tachycardia utilizing the APs as a requisite limb with cooling of the catheter tip temperature to a maximum of -30℃ for less than 45 s. Cryo-ablation was performed for 4 min at a temperature of -80℃ only if ice-mapping abolished the pre-excitation or retrograde conduction over the AP without injury to the AV nodal conduction. Results Cryo-ablation was acutely successful in all eleven patients. No permanent cryo-related complications or adverse outcomes were reported. During the follow-up (range 14–26 months), no patients experienced any arrhythmia recurrences. Conclusion Ice-mapping was a feasible and reliable method to determine the exact location of the APs owing to the possibility of validating the ablation site. Cryo-ablation of APs located near the AV junction is a safe and efficacious technique with a high success rate over the long term. IRB information Ethical Committee of Japan Red Cross Yokohama City Bay Hospital #2018−19.

Introduction: The “crosstalk” (CST) ablation technique has been reported to reduce unnecessary ablation during cryoballoon (CB) ablation (CBA). Nevertheless, it is unclear which situations will necessitate the adoption of the technique. Methods and Results: The effect of the technique was analyzed in AF patients underwent CBA from July 2017 to February 2020. The balloon occlusion status and nadir temperature (NT) were compared, and all ablated PVs were categorized into three groups according to the necessity and effectiveness of the technique. Of 1082 superior PVs (SPVs), 16, 40, and 1026 were identified in the CST success group, CST failure group, and control group, respectively. The proportion of SPVs ablated with complete occlusion with CB was significantly higher in the CST success group (100%) than in the CST failure group (16.7%) or control group (49.4%) (CST success group vs. CST failure group, p

Cryoballoon ablation is an established catheter-based approach to treat atrial fibrillation (AF). However, thromboembolic events cannot be avoided during cryoablation. There is little data regarding the blood coagulation status during freezing.The thrombin antithrombin complex (TAT) and prothrombin fragment 1+2 (F 1+2) of patient blood were measured during cryoballoon application when the cryoballoon temperature reached the nadir in 63 AF patients. TAT was also measured from porcine blood during cryoballoon freezing in 5 pigs.The TAT and F 1+2 increased from 6.60 ± 5.65 to 9.16 ± 7.28 ng/mL (P = 0.004) and from 279.6 ± 146.4 to 323.6 ± 169.1 pmol/L (P = 0.003) between the control and during freezing, respectively. The TAT increased from 0.46 to 0.87 ng/mL during freezing compared to that of pre-freezing (P < 0.05), and it returned to 0.39 ng/mL in 30 minutes after an intravenous edoxaban administration (N.S.).Dabigatran failed to exert sufficient anticoagulant effects during cryofreezing. In contrast, intravenous edoxaban seemed to provoke anticoagulation effects under extreme low temperature circumstances.

Background Adenosine triphosphate (ATP) can provoke acute reconnections after pulmonary vein isolation (PVI). This study aimed to investigate dormant conduction (DC) after ablation with second-generation cryoballoon (CB). Methods Two hundred sixteen patients (148 male; age 64 ± 9 years) with atrial fibrillation (AF) were included. After a successful PVI with the CB, 20 mg of ATP was administered. All patients were followed up for 425 ± 56 days. Results Seven hundred ninety-five out of 864 (92%) PVs were successfully isolated solely by the CB. DCs were revealed in 8 (3.7%) after ATP injections. AF recurrences occurred in 2 out of 8 patients, while no AF recurrences could be documented in 6 out of 8 patients with DCs after a blanking period of 3 months (25% vs. 75%). In contrast, 29 (13.9%) patients without DCs had AF recurrences, and there was no significant difference between those with and without DCs regarding the recurrence rate of AF ( p = 0.38). There were no reliable predictors of DCs after the PVI with the CB. Conclusion The present study demonstrated a low rate of transient PV reconnection after adenosine infusion following successful PVI with the CB. There was no reliable predictor of DCs. Further studies will be needed in order to appreciate the prognostic value of adenosine testing after successful PVI with the CB.

Background Pulmonary vein isolation (PVI) using a cryoballoon (CB) is utilized for treating atrial fibrillation. This study aimed to assess the effect of the procedural characteristics of CB-based PVI (CB-PVI) on late PV reconnections.Methods and Results:A total of 389 consecutive patients underwent the CB-PVI as their index procedure; 45 consecutive patients underwent re-do procedures (184±87 days after the index CB-PVI). A total of 146 of 178 PVs (82%) remained isolated. The occlusion grade was evaluated in 171 PVs. Complete PV occlusion by the CB (grade 4) was obtained in 122 of 171 PVs (71%) during the index CB-PVI and the PVI status was maintained in 111 PVs (91%). Among the remaining 49 CB-PVIs without complete PV occlusion (grades 1-3), 20 PVs (41%) had late PV reconnections despite successful PVI during the index CB-PVI. A "pull-down maneuver" was performed in 20 PVs because of leakage of blood at the inferior aspect of the PVs, and all those PVs with a successful pull-down maneuver maintained their PVI status. A multivariate analysis demonstrated that the presence of complete PV occlusion was the only independent predictor for persistence of PVI. Conclusions The occlusion grade was a reliable predictor of the long-term durability of PVI.

Introduction Pulmonary vein isolation (PVI) using a cryoballoon (CB) is a useful tool for treating atrial fibrillation (AF); however, the clinical efficacy of the CB has never been fully investigated in patients with a left common pulmonary vein (LCPV). Methods and results Three hundred twenty-four consecutive paroxysmal AF patients underwent PVI with a CB. Three-dimensional computed tomography was performed in all patients before the ablation. The clinical outcomes of the AF ablation between patients with (Group A) and without an LCPV (Group B) were compared. An LCPV was observed in 27 (8%) patients. There were no significant differences in the procedure time (149±45 min vs. 143±40 min, respectively; P = 0.42) and percentage needing touch up ablation between the two groups (26% vs. 20%, respectively; P = 0.45). At a mean follow-up of 454±195days, 282 of 324 (87%) patients were free from any atrial tachyarrhythmias (ATs) after a single procedure. Twenty out of 27 (74%) Group A patients and 262 of 297 (88%) Group B patients were free from ATs (15-month Kaplan-Meier event free rate estimates, 77% and 89%, respectively; P = 0.02). A multivariate analysis identified the presence of an LCPV and the left atrial diameter as reliable predictors of recurrent ATs. Conclusions The long-term clinical outcomes of ablation of AF with the CB was worse in patients with an LCPV than in those without. The presence of an LCPV and the LA size seemed to be reliable predictors of a worse outcome. This article is protected by copyright. All rights reserved

INTRODUCTION: Ethanol infusion (EI) in the vein of Marshall (VOM) has multifactorial effects that could be synergistic to pulmonary vein isolation (PVI) in ablation of atrial fibrillation (AF). The efficacy of radiofrequency (RF) versus cryoablation when combined with a VOM-EI has never been investigated. The aim of this study is to evaluate outcome differences of AF ablation using RF versus cryoablation when combined with a VOM-EI. MATERIALS AND METHODS: Consecutive patients (n=132) underwent catheter ablation of paroxysmal AF with either RF or cryoballoon (CB) for PVI combined with VOM-EI. Bi-directional conduction block at the mitral isthmus was attempted. The end-point was the freedom from any atrial arrhythmias documented after a blanking period of 90 days after the procedure. RESULTS: Kaplan-Meier estimates of the arrhythmia-free survival after 1 year were 63.8 (RF + VOM), and 82.7 % (CB + VOM), respectively. Comparison between CB + VOM versus RF + VOM reached a significance (p=0.0292). The periprocedural complication rate was comparable in both groups (5.0 % RF, 5.8 % CB; p=0.14) with a significant difference in the incidence of phrenic nerve palsy (0 % RF, 2.0 % CB; p

Introduction Pulmonary vein isolation (PVI) and linear ablation with a roof line and bottom line on the left atrial (LA) posterior wall (LAPW) can be achieved with a cryoballoon (CB). This study sought to investigate the long-term durability of these linear lesions. Methods and results Among 290 persistent patients with atrial fibrillation (AF) who had undergone linear ablation with a CB on the roof and bottom line of the LAPW in addition to the PVI, we analyzed those patients who underwent a re-do AF ablation. Arrhythmia recurrence was confirmed in 70 (24%) out of 290 patients, and 47 (16%) patients underwent re-do sessions. At the beginning of the re-do ablation, we examined the reconnection sites of the linear lesions on the LAPW and PVI. Maintenance of the conduction block on the LAPW roof and bottom lines was observed in 35 out of 47 patients (74.5%), and 16 out of 35 patients (45.7%), respectively. The length of the roof line was significantly shorter in patients with preservation of the conduction block on the LAPW roof than in those without (36.2 ± 6.5 mm vs 41.6 ± 4.7 mm, P = .02). Conclusion Durable lesions could be obtained after linear ablation with the CB for the LAPW roof line, especially in those with a relatively short LAPW roof line. However, patients requiring touch-up ablation with radiofrequency were included, and that was associated with a potential financial implication.

Purpose The aim of this study was to test regional pharmacological effects of an antiarrhythmic agents to predict ablative effects. Background The vein of Marshall (VOM) providing vascular access to myocardial tissue has been used for ablative purposes using ethanol. Methods A total of 35 patients (male 21, 63.2 ± 7.8 years old) were included. A balloon-tipped infusion catheter was inserted into the VOM. Endocardial ultrahigh-resolution mapping was performed along the VOM region to record the change in atrial electrograms (AEs) after VOM injection of cibenzoline of 3.5 mg during sustained atrial fibrillation (AF). Subsequently, ethanol was infused into the VOM and ablative region was mapped. Results In 17 patients (49 %), cibenzoline reduced AEs amplitude by >50%, all of which had also complete elimination of AEs following ethanol (Group A). In 18 patients (Group B), cibenzoline failed to eliminate AEs; yet, in 13 of 18 AEs were eliminated by ethanol. In the remaining five patients, ethanol did not eliminate AE. Conclusions Cibenzoline into the VOM could reliably predicts the results of subsequent ethanol infusion into the VOM using ultrahigh-resolution mapping system, which leads to avoid unnecessary permanent lesion creation by ethanol infusion.

We present a paroxysmal atrial fibrillation (AF) patient who had frequent AF events originating from a persistent left superior vena cava (PLSVC) with an unsuccessful catheter ablation using a non-irrigated radiofrequency catheter and was successfully cured by a successful PLSVC isolation using a second-generation cryoballoon catheter (28-mm, second-generation cryoballoon, Arctic Front Advance, Medtronic, Minneapolis, MN, USA).

Aims Anomalous origin of the coronary artery (AOCA) with an inter-arterial course (IAC) between the great vessels poses a risk for a life-threatening cardiovascular event. We assessed, in a registry-based study, the clinical features, treatment strategies, and prognoses of life-threatening cardiovascular events ensuant to AOCA. Methods and results Included were 65 AOCA patients (48 men/17 women, aged 41 ± 23 years) from 40 clinical centres who had experienced sudden cardiac arrest (SCA) (n = 30), acute myocardial infarction (AMI) (n = 5), angina (n = 23), or syncope (n = 7). The anomalous vessel was the right coronary artery in 72% of patients and left coronary artery in 28%; the ostium was slit-like in 42%. Coronary luminal narrowing ≥75% was absent in patients with SCA or syncope (86% and 57%, respectively), but occlusion or narrowing was seen in those with AMI (100%) or angina (52%). Age ≤40 years, male sex, sporting activity, absence of prodromal symptoms, acutely angled (≤30°) take-off from the aorta, and absence of luminal narrowing of the IAC segment were associated with SCA in this patient group. Coronary vasospasm was inducible in 12 of 17 patients without coronary narrowing. Management included surgical revascularization (n = 26) percutaneous coronary intervention (n = 9), and medical treatment (n = 26). Four SCA patients died while hospitalized; no others died during the median 5.0 (range, 1.8–7.0)-year follow-up period. Conclusions In patients with AOCA, age ≤40 years, male sex, sporting activity, and an acute take-off angle appear to be risk factors for SCA. Appropriate management can be beneficial. Confirmation in a large-scale study is warranted.

Anticoagulants are prescribed for prevention of thromboembolic events (TE) of atrial fibrillation (AF), however, their effects have a negative impact on disastrous bleeding outcomes. Idarucizumab was developed to reverse the anticoagulation effects of dabigatran. This study aimed to retrospectively investigate the clinical efficacy and safety of idarucizumab in the setting of progressive emergent bleeding events associated with catheter ablation (CA). Dabigatran is given uninterruptedly as an anticoagulant in patients undergoing CA of AF. The capacity of idarucizumab to reverse the anticoagulant effects of dabigatran in patients with cardiac tamponade associated with CA was examined by measuring the activated partial thromboplastin time (aPTT), active clotting time (ACT), and prothrombin international normalizing ratio (PT-INR). The primary endpoint was effective hemostasis. This analysis included 21 patients receiving idarucizumab, given for restoration of hemostasis. In all 21 patients, hemostasis was restored at a median of 205.6 ± 14.8 min. Normal intraoperative cessation of bleeding was reported in 16 patients, and completion of hemostasis was also ascertained in the remaining four within 5 h. No TEs occurred within 72 h after the idarucizumab administration. Despite a significant reduction in the aPTT and ACT, no significant change was observed in PT-INR after administering idarucizumab. In emergency situations, idarucizumab was able to reverse dabigatran within a relatively short period without any serious adverse events.

Background Atrial fibrillation (AF) often coexists with Wolff-Parkinson-White (WPW) syndrome. We compared the efficacy of Kent bundle ablation alone and additional AF ablation on accompanying AF, and examined which patients would still have a risk of AF after successful Kent bundle ablation. Methods This retrospective multicenter study included 96 patients (56 ± 15 years, 72 male) with WPW syndrome and AF undergoing Kent bundle ablation. Some patients underwent simultaneous pulmonary vein isolation (PVI) for AF. The incidence of post-procedural AF was examined. Results Sixty-four patients underwent only Kent bundle ablation (Kent-only group) and 32 also underwent PVI (+PVI group). There was no significant difference in the basic patient characteristics between the groups. Additional PVI did not improve the freedom from residual AF compared to Kent bundle ablation alone (p = 0.53). In the Kent-only group, AF episodes remained in 25.0% during the follow-up (709 days). A univariate analysis showed that age ≥60 years, left atrial dimension ≥38 mm, B-type natriuretic peptide (BNP) ≥40 pg/ml, and concomitant hypertension were predictive factors for residual AF. However, in the multivariate analysis, only BNP ≥40 pg/ml remained as an independent predictive factor (HR = 17.1 and CI: 2.3–128.2; p = 0.006). Conclusions Among patients with WPW syndrome and AF, Kent bundle ablation alone may have a sufficient clinical impact of preventing recurrence of AF in select patients. Screening the BNP level would help decide the strategy to manage those patients.

Aims Pulmonary vein (PV) isolation (PVI) utilizing a cryoballoon (CB) has become one of the standard therapeutic options for atrial fibrillation (AF). However, it connotes a potential risk of cerebral ischaemic events (CIEs). This study aimed to clarify the prevalence of CIEs after PVI using second-generation CBs assessed by magnetic resonance imaging (MRI) of the brain. Methods This prospective observational study consisted of 160 patients that underwent PVI with second-generation CBs for drug-refractory AF. Irrigated radiofrequency (RF) ablation for ‘touch-up’ procedures was utilized when conduction gaps between the left atrium (LA) and PVs were found after the CB application. Radiofrequency linear ablation was added in select patients. Cerebral MRI and neurological examinations were performed on the day following the ablation procedure. Results The MRI depicted micro-cerebral infarctions in 43 patients (26.9%, 1.49 lesions per case). All patients were free from symptomatic focal neurological deficits. Touch up ablation was required for the PVI establishment in 35 patients (21.9%). Linear ablation was performed in 59 patients (36.9%). Additional RF ablation within the LA was an independent risk of CIEs in the uni- and multivariate analyses. When the analyses were limited to patients who had undergone only CB ablation, CIEs were found in 12 of 66 patients (18.2%). Conclusion Pulmonary vein isolation utilizing second-generation CBs carries a negligible risk of symptomatic CIEs; however, it includes a comparable risk of asymptomatic CIEs as in the previous similar reports using the first-generation CB. Radiofrequency applications in addition to the CB within the LA were the only predictor of this adverse effect.

Background Diaphragmatic electrogram recording during cryoballoon ablation (CB-A) of atrial fibrillation is commonly used to predict phrenic nerve palsy (PNP). Objective The purpose of this study was to investigate a novel method for predicting PNP at an earlier stage to prevent sustained PNP. Methods A total of 197 patients undergoing CB-A were enrolled. We attempted to detect PNP using fluoroscopic images of diaphragmatic contractions and by monitoring diaphragmatic compound motor action potentials (CMAPs) provoked by superior vena cava (SVC) and left subclavian vein (LCV) pacing during CB-A for bilateral pulmonary veins (PVs). Pacing of the SVC and LCV was performed at 2 outputs, 1 exceeding the pacing threshold by 10% (MIN) and the other at maximum output (MAX). The time from freezing to the initiation of PNP, values of the CMAP amplitude, and severity of PNP were compared for the 2 outputs. Results There was a significant difference in the time from freezing to initiation of PNP between MIN and MAX pacing (25.7 ± 5.7 vs 81.3 ± 7.4 seconds, P Conclusion Pacing the SVC and LCV with lower output detect PNP significantly earlier than maximal output pacing and leads to recovery from PNP on the order of hours postprocedure rather than months.

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. 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). 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). 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.

Background The cryoballoon (CB) can be utilized for extra pulmonary vein (PV) ablation such as for a left atrial (LA) posterior wall (LAPW) isolation. However, scrutiny of the esophageal injuries during the LAPW isolation has never been performed. We sought to thoroughly investigate the esophageal lesions (ELs) and gastric hypomotility (GH) caused by an LAPW isolation using a CB. Methods A total of 101 persistent atrial fibrillation patients who underwent an LAPW isolation using a CB were enrolled. The CB was applied on the roof and bottom area of the LAPW after a PV isolation. The luminal esophageal temperature (LET) was monitored by a thermistor probe during the CB applications. When the LET reached 15°C, the freezing application was prematurely interrupted. Esophagogastroscopy was performed on the next day following the ablation. Results All PVs were successfully isolated in all patients. A successful LAPW isolation solely with CB ablation was performed in 72 (71.3%) patients. Cryofreezing applications were prematurely interrupted due to low LETs in 49 (48.5%) patients predominantly during the LA bottom line ablation. ELs and GH were observed in 11 (10.9%) and 16 patients (15.8%), respectively. The nadir LET tended to be lower in patients with ELs and GH than in those without (ELs: 14.8 ± 4.5°C vs 17.4 ± 6.0°C, P = 0.17; GH: 15.5 ± 4.5°C vs 17.5 ± 6.1°C, P = 0.23, respectively). Conclusions Esophageal complications such as ELs and GH occur during the LAPW isolation with a CB. There was no reliable predictor of those adverse events.

Complete occlusion of the pulmonary veins (PVs) with the cryoballoon (CB) is considered to be the crucial factor for a successful PV isolation (PVI). We investigated whether a complete occlusion was indispensable for a successful CB based PVI of every PV.Atrial fibrillation patients (n=123, 97; paroxysmal) undergoing a de novo PVI were enrolled. A total of 477 PVs were analyzed. The occlusion grade (OG) was scored as follows: OG3 (complete occlusion), OG2 (incomplete occlusion with slight leakage), OG1 (poor occlusion with massive leakage). There was no significant difference in the CB temperature (CBT) at all measured time points (from 30 to 120sec after freezing) and nadir CBT between OG2 and OG3 in all PVs except for the right inferior PV (RIPV). The RIPV isolation success rate was significantly lower for the OG2 status than OG3 (97.5 vs. 57.6%; p0.0001). In contrast, there was not significant difference in the isolation success rate of the other three PVs between OG2 and OG3. In particular, the success rate of the right superior PV (RSPV) isolation was95% for both OG2 and OG3. Phrenic nerve paralysis (PNP) was provoked during the RSPV isolation in two patients in whom the RSPVs were frozen during OG3.An OG3 may not always be required for a successful PVI of all PVs except the RIPV. OG2 could have comparable effects as OG3 in terms of a successful RSPV isolation. Not aiming for OG3 for the RSPV may reduce the risk of PNP.

Background Coronary artery spasm usually has a good prognosis, except when it induces lethal ventricular arrhythmias. Implantable cardioverter-defibrillator (ICD) implantation in addition to optimal medical therapy including prescription of coronary vasodilators and smoking cessation is a therapeutic option for coronary artery spasm patients who present with lethal ventricular arrhythmia. Subcutaneous ICDs are now available as an alternative to conventional transvenous ICDs. Case Summary We report the first case of a 50-year-old Japanese male without any structural heart disease who presented with ventricular fibrillation caused by coronary artery spasm, and underwent subcutaneous ICD implantation for secondary prevention of sudden cardiac death (SCD). We attributed his aborted SCD to coronary artery spasm based on findings of cardiac catheterization including acetylcholine provocation test and cardiac electrophysiological study. During the 1 year of follow-up, the patient discharged on calcium channel blockers and nicorandil has been free of angina, ventricular arrhythmias, and appropriate ICD therapy. Discussion Coronary artery spasm patients with aborted SCD may be good candidates for implantation of subcutaneous ICDs, because most of them have no need for concomitant bradycardia therapy, cardiac resynchronization therapy, or anti-tachycardia pacing therapy.

Background: Ventricular fibrillation (VF) in Brugada syndrome (BrS) is known to occur more frequently during nighttime and from spring to early summer. In this study, we investigated whether early repolarization syndrome (ERS) has the same seasonal, weekly, and circadian distribution of VF events as BrS using data from the “J-wave associated with prior cardiac event” (J-PREVENT) registry. Methods: The study included 90 consecutive patients with BrS and 31 patients with ERS during a mean follow-up of 49±37 months. Follow-up data from implantable cardioverter-defibrillators were evaluated in all cases. Results: In patients with ERS, the circadian distribution of VF episodes differed among the four 6-h periods, with a significant peak from midnight to 6:00 am (p

Dormant conduction (DC) induced by intravenous adenosine triphosphate (ATP) after pulmonary vein (PV) isolation (PVI) could predict subsequent PV reconnection (RC) sites. This study aimed to investigate the relationship between the DC and RC sites during the long-term follow-up. Ninety-one consecutive patients (62 males; mean age, 62 ± 11 years) with symptomatic persistent (n = 18) or paroxysmal (n = 73) atrial fibrillation (AF) who underwent PVI were included in this study. After a successful PVI, we administered ATP to reveal the DC sites. In total, DC sites were observed in 46 (51 %) patients, and all were left un-ablated after marking or tagging all of them using fluoroscopic images and a three-dimensional (3D) mapping system. After the follow-up period (14.8 ± 3.6 months), AF recurred in 29 (32 %) patients, all of whom had a DC in the initial ablation session, and underwent redo sessions. We divided the DC sites into three groups; in group A, the RC sites differed from the DC sites, in group B, the RC sites were identical to the DC sites, and in group C, the RC sites involved both DC and other sites. As a result, 20 (69 %), 3 (11.5 %), and 6 (19.5 %) patients belonged to groups A, B, and C, respectively. Statistical analyses comparing the agreement between DC and the RC sites yielded a weak relationship. DC sites implying RC sites had a weak agreement, and other options to predict RC sites will be required to improve the clinical benefit of CA of AF.

Background Serelaxin, a recombinant form of human relaxin-2, is in development for treating acute heart failure (AHF) and a Phase II study in Japanese AHF patients was conducted. Methods and results A randomized, double-blind, placebo-controlled study of serelaxin at 10 and 30 µg·kg(-1)·day(-1)continuous intravenous infusion for up to 48 h, added to standard care for Japanese AHF patients. Primary endpoints were adverse events (AEs) through Day 5, serious AEs (SAEs) through Day 14, and serelaxin pharmacokinetics. Secondary endpoints included changes in systolic blood pressure (SBP) and cardiorenal biomarkers. A total of 46 patients received the study drug and were followed for 60 days. The observed AE profile was comparable between the groups, with no AEs of concern. Dose-dependent increase in the serum concentration of serelaxin was observed across the 2 dose rates of serelaxin. A greater reduction in SBP was observed with serelaxin 30 µg·kg(-1)·day(-1)vs. placebo (-7.7 [-16.4, 1.0] mmHg). A greater reduction in NT-proBNP was noted with serelaxin (-50.8% and -54.9% for 10 and 30 µg·kg(-1)·day(-1), respectively at Day 2). Conclusions Serelaxin was well tolerated in this study with Japanese AHF patients, with no AEs of concern and favorable beneficial trends on efficacy. These findings support further evaluation of serelaxin 30 µg·kg(-1)·day(-1)in this patient population.

Phrenic nerve (PN) injury is a typical complication of cryoballoon ablation (CBA) of pulmonary veins. The PN function is monitored by palpating the abdomen during PN pacing, and freezing is prematurely terminated when a reduction in the diaphragm movement is recognized. This study aimed to investigate the efficacy and safety of a “pull-back” maneuver to prevent PN injury. A total of 284 patients were included, and the PN function was monitored by recording the diaphragmatic compound motor action potentials (CMAP) during the cryoballoon applications for pulmonary vein (PV) isolation. When the CMAP amplitude was reduced by more than 30% compared to the control, the “pull-back” maneuver (PBM) was undertaken to prevent PN injury. The average CMAP amplitude significantly decreased from 0.81 ± 0.04 to 0.31 ± 0.21 (p

A point-by-point application around the antral area of the left atrium using radiofrequency energy (RF) has been widely performed for the electrical isolation of pulmonary veins (PVI) for the cure of atrial fibrillation (AF). The cryoballoon has evolved as a new therapeutic tool for performing a PVI, and it has unique characteristics that differ from the other energy sources for electrical cautery ablation such as RF energy. Just a single delivery of cryofreezing energy has the capability to accomplish the PVI and is called a “one-shot” ablation. A transient electrical effect called “ice-mapping” is also a peculiar characteristic to cryofreezing energy, and this effect can be useful to avoid collateral and unintentional damage to important cardiac tissue such as the compact AV node, normal conduction system, and sinus node. Cryo-adherence provoked at the interface between the cryocatheter and cardiac tissue is also an advantageous effect of the cryofreezing system, and it guarantees the stability of the cryocatheter against the target tissue. The long-term results of the freedom from any atrial arrhythmias after undergoing a PVI using cryofreezing energy to treat AF are almost comparable to those of RF energy. Further, the incidence of complications associated with the ablation procedure is relatively lower than that of RF energy, however, phrenic nerve palsy is the most frequent adverse event associated with the PVI using the cryoballoon. An appropriate prophylactic strategy and carefully performed procedure are required to avoid this undesirable complication.

The vein of Marshall (VOM) is highlighted as a new target tissue for catheter ablation of atrial fibrillation (AF). It anatomically arises from the coronary sinus and courses obliquely toward the ridge between the left inferior pulmonary vein (LIPV) and left atrial appendage. It also includes a parasympathetic nerve bundle, which is associated with the initiation and maintenance of AF. We were able to demonstrate the feasibility and safety of an ethanol infusion (EI) into the VOM (EIVOM) and also showed the clinical implications related to the therapeutic effects on AF. The EIVOM is able to eliminate ectopic atrial beats arising from the VOM, complex fractionated atrial electrograms, parasympathetic innervation fibers, and presumably the epicardial conduit connecting the coronary sinus musculature and left atrium. After performing the EIVOM, bidirectional conduction block at the mitral isthmus and LIPV was easily created due to the injurious effects starting from the epicardium to endocardium resulting in transmural injury to the left atrial wall. In addition, the EIVOM is able to partially isolate, predominantly the LIPV at its lower aspect and left superior PVs in a sporadic cases. No adverse events have been provoked by this procedure.

Background Phrenic nerve (PN) palsy (PNP) is the most frequent complication of cryoballoon ablation (CBA) of atrial fibrillation (AF). The major complication of this technique seems to be right-sided PN injury (PNI) following ablation of the right pulmonary veins (PVs). We sought to assess the incidence and prognosis of left-sided PNI during CBA. Methods CBA was performed in 448 patients with AF. During the ablation of the left-sided PVs, the PN was paced from the left subclavian vein with a pacing output just exceeding the threshold by 10 ∼ 20%. The right and left arm 12-lead electrocardiogram electrodes were positioned 5 cm above the xiphoid process and 16 cm along the left costal margin. The amplitude of the compound motor action potentials was recorded during the CBA. Results Two thousand one hundred seventy-eight CBA applications were delivered in 1,094 left-sided PVs. PNI occurred in 29 patients (6.5%); the PN could be captured by an increasing pacing output in 21 patients (4.7%), and premature termination of the freezing was required to avoid PNP in eight patients (1.8%). The PN function recovered before discharge; however, it took 7 months for one patient to completely recovery from the PNP. Conclusions Left-sided PNP could be provoked during a left-sided CBA procedure. Assessment of the left PN during the CBA was necessary to prevent left-sided PNP.

Background Although electrophysiological study is often performed in Brugada syndrome (BrS) to assess inducibility of ventricular arrhythmias (VA), the utility of electrophysiological study in early repolarization syndrome (ERS) remains unknown. The aim of the present multi-center observational study was to compare inducibility of VA in ERS with BrS, and to investigate any association between inducibility and recurrence of arrhythmic events in these patients. Methods The J-PREVENT registry consists of patients with early repolarization or Brugada type 1 ECGs, a history of prior cardiac events, and no structural heart disease. Patients in the registry with implantable cardioverter-defibrillators (ICDs) and who underwent electrophysiological study were enrolled. VA inducibility was assessed by programmed electrical stimulation performed at two different sites in the right ventricle with up to three extrastimuli. The occurrence of VA during follow-up was determined by interrogation of the patients׳ ICDs. Results Of the 79 patients studied (72 males, mean age 44±13 years), 21 patients (27%) had ERS, and 58 had BrS, 20 of whom also had early repolarization in the inferolateral leads. VA was induced in 9 patients (43%) and 45 (78%) with ERS and BrS, respectively (p=0.006). During a median follow-up of 1453 days, occurrence rate of VA was similar between ERS and BrS (p=0.35). Inducibility was not associated with occurrence of VA in either syndrome. Conclusions In patients with ERS with prior history of cardiac events, VA was induced in 43% of patients during electrophysiological study, approximately half that of BrS. Inducibility was not associated with occurrence of VA during follow-up, although this was true of BrS patients as well. Electrophysiological study may play a limited role in risk stratification in ERS.

Objectives This study sought to determine whether ethanol infusion in the vein of Marshall (VOM) can ablate intrinsic cardiac nerves (ICN). Background ICN cluster around the left atrial epicardium and are implicated in the genesis of atrial fibrillation (AF). Methods Patients undergoing catheter AF ablation underwent adjunctive ethanol injection in the VOM. A multipolar catheter was introduced in the VOM and used for high-frequency stimulation (HFS), either as HFS with P-wave synchronized (SynchHFS), 30 pulses, 100 Hz (n = 8) or as HFS with 3 to 10 s bursts (BurstHFS), 33 Hz (n = 72) at 25 mA for 1-ms duration. Atrioventricular (AV) nodal conduction slowing (asystole >2 s or R-R interval prolongation >50%) and AF inducibility were assessed before and after VOM ethanol infusion. Up to 4 1-ml infusions of 98% ethanol were delivered via an angioplasty balloon in the VOM. Results SynchHFS induced AF in 8 of 8 patients. In 4 of 8 AF initiated spontaneously without VOM capture. No parasympathetic responses were elicited by SynchHFS. BurstHFS was performed in 32 patients undergoing de novo AF ablation (Group 1) and 40 patients undergoing repeat ablation (Group 2). Parasympathetic responses were found in all 32 Group 1 patients and in 75% of Group 2 patients. After VOM ethanol infusion, parasympathetic responses were abolished in all patients (both groups). There were no acute complications related to VOM ethanol infusion. Conclusions The VOM contains ICN that connect with the AV node and can trigger AF. Retrograde ethanol infusion in the VOM reliably eliminates local ICN responses. The VOM is a vascular route for ICN-targeting therapies.

Macro-reentrant ventricular tachycardias (VT) utilizing the bundle branches and Purkinje fibers have been reported as verapamil sensitive VT (idiopathic left VT), bundle branch reentrant VT (BBRT) and inter-fascicular reentrant tachycardia (inter-fascicular VT). However, diagnostic confusion exists with these VTs due to the difficulty in differentiating between them with conventional electrophysiological (EP) studies. The aim of this study was to clarify the EP and anatomical entity of inter-fascicular VT, and provide successful methods for the radio frequency catheter ablation (RFCA) of inter-fascicular VT. A total of nine patients were included in this study. All patients were diagnosed with idiopathic left VT in the first session, and underwent a second session after a failed RFCA. Detailed EP studies guided by a three-dimensional (3D) mapping system were performed to further analyze the VTs. All VTs were finally diagnosed as inter-fascicular VT. They were successfully cured with RFCA targeting the left anterior or posterior fascicle, which was regarded as a requisite part of the reentrant circuit of the inter-fascicular VT, using 3D and fluoroscopic images combined with a detailed EP investigation instead of the conventional RFCA method targeting Purkinje potentials for the RFCA of idiopathic left VT. Inter-fascicular VT could be misdiagnosed as idiopathic left VT due to the limitations of the conventional EP study. Failed RFCA in presumptive idiopathic left VT cases has to be carefully investigated by further analysis, and a tailored RFCA strategy targeting the requisite portions of the left fascicles in the inter-fascicular VT reentrant circuit will be required for the successful elimination of the inter-fascicular VT.

Background The aim of this study was to investigate the use of imaging techniques to predict the response to cardiac resynchronization therapy (CRT) in patients with non-ischemic cardiomyopathy (NICM) by simultaneous assessment of left ventricular (LV) dyssynchrony and myocardial perfusion in a single nuclear scan of the heart. Methods Patients indicated for CRT device implantation underwent a resting myocardial perfusion assessment with single photon emission computed tomography (MP-SPECT) examination using technetium-99 m methoxyisobutylisonitrile prior to device implantation. CardioGRAF and cardioBull software (FUJIFILM RI Pharma, Tokyo, Japan) were used to analyze the LV mechanical dyssynchrony and myocardial viability, respectively. Patient follow-ups were performed at 6 months after device implantation. CRT response was defined as a ≥10% decrease in the LV end systolic volume. Results A total of 43 patients with NICM were analyzed. Using the cutoff points of 6.2 for the dyssynchrony index and 66% for LV myocardial perfusion, the combined indices predicted CRT response with a sensitivity of 77.8% and specificity of 91.2%. Conclusion Combined assessment of MP-SPECT and a measure of LV mechanical dyssynchrony showed good predictive ability in patients with non-ischemic heart failure.

Background When drug-induced coronary spasm provocation tests are performed, a washout period of >48h for calcium channel blockers (CCBs) is uniformly recommended. However, each CCB has a distinct half-life, and little is known about the influence of prior oral administration of CCBs on acetylcholine provocation test to evaluate coronary vasomotor reaction. Methods and results We examined 245 consecutive patients with suspected vasospastic angina who had undergone acetylcholine provocation test. Of those patients, 29 patients had been on amlodipine, an ultra-long term acting CCB (group A), 34 on other CCBs (group O), and 182 patients on no CCB (group N). After CCBs had been withheld > 48h, we performed acetylcholine provocation, which resulted in 152 positive, 36 intermediate, and 57 negative reactions. We evaluated coronary artery tone calculated as follows: (luminal diameter after nitrate−baseline luminal diameter)÷(luminal diameter after nitrate)×100 (%). In group A patients, coronary artery tone was lower (A:9.1±6.9% vs. O:11.7±8.3% vs. N:12.1±8.5%, p=0.0011) and the positive rate of acetylcholine provocation test was lower than group O and group N (A:41% vs. O:68% vs. N:64%, p=0.047). Multivariate logistic analysis showed that taking amlodipine until 2days before acetylcholine provocation test was a significant inverse predictor for acetylcholine-provoked coronary spasm (odds ratio 0.327; 95% confidence interval 0.125–0.858, p=0.023). Conclusions Residual vasodilatory effects of ultra-long acting CCB may decrease coronary artery tone and the vasoconstrictive reaction to acetylcholine suggesting that a 2-day pre-test drug holiday may not be long enough.