Retrograde fast pathway cryoablation inside the coronary sinus for slow-fast atrioventricular nodal reentrant tachycardia in a patient with persistent left superior vena cava.

INTRODUCTION: Persistent left superior vena cava (PLSVC) is accompanied by enlarged coronary sinus (CS) and deformation of the triangle of Koch. This makes anatomical evaluation of the atrioventricular (AV) nodal pathways difficult. METHODS: We attempted cryoablation of retrograde fast pathway located in the enlarged CS roof of PLSVC for slow-fast AV nodal reentrant tachycardia (AVNRT) induced by inadvertent antegrade fast pathway elimination during ablation of left atrial tachycardia. RESULTS: Slow-fast AVNRT was successfully eliminated without AV block progression. CONCLUSIONS: This is the first case of successful retrograde fast pathway ablation of the CS ostial roof for slow-fast AVNRT with PLSVC.

How to perform effective cryoballooon ablation of the left atrial roof: Considerations after experiencing more than 1000 cases.

INTRODUCTION: Cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to a pulmonary vein isolation has been expected to improve the clinical outcomes post-atrial fibrillation (AF) ablation. We demonstrated the characteristics and efficacy of CBA of the LA roof through our experience with a large volume of procedures. METHODS: Among 1036 AF ablation procedures with CBA of the LA roof, 834 patients who underwent a de novo ablation were analyzed. RESULTS: Complete LA roof line conduction block was obtained in 767 patients (92.0%) solely by CBA (Group A). Compared with the other patients (Group B), the mean nadir balloon temperature during CBA of the LA roof (-44.5 ± 5.6°C for Group A vs. -40.5 ± 7.5°C for Group B, p < .01) and number of cryoballoon applications during the LA roof ablation with a circular mapping catheter located in the left superior pulmonary vein (1.3 ± 0.8 for Group A vs. 1.6 ± 1.0 for Group B, p = .02) were significantly lower in Group A. A multivariate analysis revealed that those were predictors of a complete LA roof conduction block after only CBA. The 1-year Kaplan-Meier atrial arrhythmia free rate estimates were 80.6% for Group A and 59.0% for Group B (p < .01). CONCLUSION: Complete LA roof line conduction block could be obtained with a cryoballoon without touch-up ablation in most cases. The LA roof CBA with a circular mapping catheter located in the right superior pulmonary vein was preferable to obtaining complete LA roof conduction block, which was important with regard to the clinical outcomes.

A novel catheter ablation strategy for non-paroxysmal atrial fibrillation combining cryoballoon, radiofrequency, and Marshall-vein ethanol ablations.

BACKGROUNDS: Catheter ablation for non-paroxysmal atrial fibrillation (non-PAF) remains challenging and more effective strategy has been required to reduce postoperative arrhythmia recurrences. This study aims to investigate the efficacy and safety of a novel extensive ablation strategy for non-PAF, that is based on a combination of cryoballoon (CBA), radiofrequency (RFA), and Marshall-vein ethanol ablations (EA-VOM). METHODS: The study was a single-center, retrospective observational study. We enrolled 171 consecutive patients who underwent de-novo catheter ablation for non-PAF under conscious sedation with a novel extensive ablation strategy that included CBA for pulmonary vein isolation (PVI) and left atrial roof ablation (LARA), RFA for mitral isthmus (MI) ablation, superior vena cava isolation, and other linear ablations and EA-VOM. Recurrence of atrial arrhythmias over 1 year, procedure outcomes, and procedure-related complications were investigated. RESULTS: A total of 139 (81.3%) patients remained in sinus rhythm during 1-year follow-up. Of the 139 patients, 51 patients (29.8%) received antiarrhythmic drugs. The mean procedure time was 204 ± 45 min. PVI and LARA ablation by CBA and MI block by RFA and EA-VOM were completed in 171 (100%) and 166 (97.1%) patients, respectively. No serious procedure-related complications were observed except for one case of delayed pericardial effusion. CONCLUSION: Approximately 80% of the study patients were AF-free during 1-year follow-up period after a single procedure based on the novel extensive ablation strategy combining CBA, RFA, and EA-VOM. This strategy for non-PAF may be preferred in terms of maintenance of sinus rhythm, safety even in high-risk patients, and relatively short procedure time.

Prevalence of gastric hypomotility after additional cryoballoon ablation of the left atrial roof.

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 < .01; RIPV diameter: 19.7 [19.0-20.5] mm vs. 23.2 [21.2-24.9] mm, p < .01; height of LA roof: 5.7 [5.1-6.1] mm vs. 8.8 [7.1-11.2] mm for, p < .01, respectively). Multivariate analysis revealed that LA roof height was a predictor of GH. Moreover, Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index (PAGI-SYM) scores increased significantly 1 week after ablation (from 1.0 [0.0-2.8] to 5.0 [3.0-11.0], p = .03) in patients with GH. CONCLUSION: The height of the LA roof may be a predictor of GH after CBA of the LA roof line. Additionally, GH-related symptoms may still appear 1 week after ablation.

Laser Balloon Ablation in Patients with a Left Common Pulmonary Vein.

Pulmonary vein isolation (PVI) with a balloon-based visually guided laser ablation (VGLA) is regarded as a useful therapeutic tool for treating atrial fibrillation (AF). The clinical efficacy of a VGLA has never been fully investigated in patients with left common pulmonary vein (LCPV). We investigated the procedural safety as well as clinical usefulness of VGLA in patients with LCPV.This study consisted of 130 consecutive patients who underwent VGLA of de novo nonvalvular paroxysmal AF.Eleven patients (8.5%) had an LCPV (ostium maximal average diameter: 27.5 ± 4.9 mm, ostium minimal average diameter: 17.7 ± 3.5 mm). Nine out of 11 (81.8%) LCPVs were successfully occluded and isolated at the ostium with a VGLA-guided PVI. The ablation procedure time was significantly shorter in the patients with than without an LCPV (61.5 ± 15.4 versus 86.9 ± 32.9 minutes, P = 0.01). There was no difference regarding the atrial tachyarrhythmia recurrence between those with and without an LCPV (P = 0.18). A total of 15 patients underwent a redo procedure, but reconnections were not observed in any of the LCPV patients.The VGLA-guided PVI was a useful therapeutic tool even in patients with an LCPV. The presence of an LCPV might not be associated with an increased risk of any atrial tachyarrhythmia recurrence.

Prone-position computed tomography in the late phase for detecting intracardiac thrombi in the left atrial appendage before catheter ablation for 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 before 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.

Predictors of Phrenic Nerve Injury During Pulmonary Vein Isolation for Curing Atrial Fibrillation With Balloon-Based Visually Guided Laser Ablation.

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.

Vagal Reactions During Laser Balloon Ablation in Patients with Paroxysmal Atrial Fibrillation.

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.

Predictors of the "Crosstalk" Phenomenon During Cryoballoon Ablation in Patients with Atrial Fibrillation.

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.

Clinical investigation of the durability of the lesions created by left atrial linear ablation with a cryoballoon.

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.

Chemical mapping as a predictor of vein of Marshall ethanol ablative effects.

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.

Experimental Study with Regard to the Effects of Energy Titration of the Laserballoon on the Lesion Creation Using Porcine Myocardium.

Laserballoon-based pulmonary vein isolation has proven to be safe and effective. However, the influence of the laser energy titration on the lesion formation has never been fully investigated. The aim of this study was to determine the relationship between the delivered laser energy and lesion size, as well as the incidence of steam pop.The whole porcine heart was excised, and the left ventricular myocardium was separated into four specimens. Myocardial specimens were embedded in a warm mattress to keep the myocardial temperature around 37°C. The laserballoon was located so that the surface of the laserballoon was attached to the myocardium. The laser energy was irradiated against the surface of myocardium at 5.5, 8.5, 10.0, and 12.0 W for 3, 5, 10, and 20 seconds. The depth, surface area, and lesion volume were measured using a digital vernier caliper.At constant laser energy and time, the lesion size increased significantly with the increasing energy (P < 0.001) and application duration (P < 0.001). The steam pop was provoked when a 12.0 W laser energy was applied for longer than 16 seconds, and it occurred in 2 out of 8 lesions.The laserballoon demonstrated the ability to create a lesion formation in a dose- and time-dependent manner. Steam pop could be provoked with high-energy irradiation.

Blood Coagulation Status during Cryofreezing Ablation and Effects of the Direct Anticoagulants Dabigatran and Edoxaban.

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.

Cryofreezing catheter ablation of adenosine triphosphate sensitive atrial tachycardia.

INTRODUCTION: Adenosine triphosphate (ATP) sensitive atrial tachycardia (AT) has been treated by radiofrequency catheter ablation. Cryofreezing energy has emerged as a novel energy source for catheter ablation. The aim of this study was to investigate the efficacy and safety of cryofreezing ablation for ATP-sensitive AT. METHODS AND RESULTS: A total of six patients with ATP-sensitive ATs were included in this study. A single atrial extrastimulation was able to initiate and terminate these ATs in all six patients. The electrophysiological findings satisfied the diagnostic criteria of ATP-sensitive AT. The ablation catheter was located at the earliest activation site of atrial excitation during the AT, and cryofreezing energy was delivered through a cryoablation catheter to perform cryomapping at temperature of -30 or -80°C. When cryomapping successfully terminated the ATs, cryoablation at a temperature of -80°C was subsequently performed. The earliest atrial activation during AT was recorded at the Koch's triangle area associated with a distinct intra-atrial activation sequence from that recorded during ventricular pacing. Cryoablation was performed at successful cryomapping sites and resulted in the complete elimination of the AT in all six patients without affecting the bidirectional atrioventricular (AV) nodal conduction. CONCLUSION: Cryofreezing energy was safe and effective in treating ATP-sensitive ATs even in patients with its origins located in the vicinity of the AV node.

The clinical impact of the left atrial posterior wall lesion formation by the cryoballoon application for persistent atrial fibrillation: Feasibility and clinical implications.

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.

Clinical investigation of esophageal injury from cryoballoon ablation of persistent atrial fibrillation.

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.

Clinical experience of idarucizumab use in cases of cardiac tamponade under uninterrupted anticoagulation of dabigatran during catheter ablation of atrial fibrillation.

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.

Predictors of a Persistent Status of Pulmonary Vein Electrical Isolation by a Cryoballoon Application for Drug-Refractory Atrial Fibrillation.

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.

Atypical Fast-Slow Atrioventricular Nodal Reentrant Tachycardia Incorporating a "Superior" Slow Pathway: A Distinct Supraventricular Tachyarrhythmia.

BACKGROUND: The existence of an atypical fast-slow (F/S) atrioventricular nodal reentrant tachycardia (AVNRT) including a superior (sup) pathway with slow conductive properties and an atrial exit near the His bundle has not been confirmed. METHODS AND RESULTS: We studied 6 women and 2 men (age, 74 ± 7 years) with sup-F/S-AVNRT who underwent successful radiofrequency ablation near the His bundle. Programmed ventricular stimulation induced retrograde conduction over a superior SP with an earliest atrial activation near the His bundle, a mean shortest spike-atrial interval of 378 ± 119 milliseconds, and decremental properties in all patients. sup-F/S-AVNRT was characterized by a long-RP interval; a retrograde atrial activation sequence during tachycardia identical to that over a sup-SP during ventricular pacing; ventriculoatrial dissociation during ventricular overdrive pacing of the tachycardia in 5 patients or atrioventricular block occurring during tachycardia in 3 patients, excluding atrioventricular reentrant tachycardia; termination of the tachycardia by ATP; and a V-A-V activation sequence immediately after ventricular induction or entrainment of the tachycardia, including dual atrial responses in 2 patients. Elimination or modification of retrograde conduction over the sup-SP by ablation near the right perinodal region or from the noncoronary cusp of Valsalva eliminated and confirmed the diagnosis of AVNRT in 4 patients each. CONCLUSIONS: sup-F/S-AVNRT is a distinct supraventricular tachycardia, incorporating an SP located above the Koch triangle as the retrograde limb, that can be eliminated by radiofrequency ablation.