Focal atrial tachycardias originating from the aorta-mitral continuty: Anatomic and electrophysiological characteristics.

BACKGROUND: The aorta-mitral annulus conjunction (AMC) is uncommon site of origin of focal atrial tachycardias (AT). Hence, the electrophysiological and ablation target characteristics are poorly described. OBJECTIVE: To describe the characteristics of AMC AT in detail. METHODS: The study enrolled 650 patients with AT, 21 (3.2%) of whom had AT originating from AMC. A comprehensive evaluation, including electrocardiography, electrophysiologic study, CT scan, and intracardiac echocardiography (ICE) was performed. RESULTS: The majority (90.5%) of ATs occurred spontaneously. The average age of this group was 48.9±21.6 years, with 12 females (57.1%). Seventeen patients had a typical biphasic P wave with a prominent positive component. The earliest activation site in the right atrium was near the His bundle with average activation -10.3±6.0 ms preceding the P wave. The successful ablation targets were distributed as follows: 1 case at 9 o'clock, 6 cases at 10 o'clock, 7 cases at 11 o'clock, 6 cases at 12 o'clock, and 1 case in the left coronary cusp (LCC). The local AMC potential differed from the commonly perceived annular potential, and was characterized by a large A and a small V (A/V ratio >1). The angle of encroachment on the LA anterior wall, compressed by the LCC, was significantly smaller in the AMC-AT group compared to the control group, which may have contributed to the arrhythmia substrate (141.7°±11.5° vs. 155.2°±13.9°, p = 0.026). CONCLUSION: A new strategy for mapping AMC ATs has been introduced. The ablation target should have an A/V ratio greater than 1.

Safety and efficacy of catheter ablation of para-Hisian accessory pathway via a direct superior vena cava approach: A multicenter study.

BACKGROUND: Radiofrequency (RF) catheter ablation of para-Hisian accessory pathways (APs) can be challenging due to proximity to the conduction system. METHODS: A total of 30 consecutive patients with para-Hisian AP were enrolled for ablation in three centers, 12 (40%) of whom had previously failed attempted ablation from the inferior vena cava (IVC) approach. Ablation was preferentially performed using a superior approach from the superior vena cava (SVC) in all patients. RESULTS: The para-Hisian AP was eliminated from the SVC approach in 28 of 30 (93.3%) patients. In the remaining two patients, additional ablation from IVC was required to successfully eliminate the AP. There were two patients experienced reversible complete atrial-ventricular block and PR prolongation during the first RF application. Long-term freedom from recurrent arrhythmia was achieved in 29 (96.7%) patients over a mean follow-up duration of 15.6 ± 4.6 months. CONCLUSION: Catheter ablation of para-Hisian AP from above using a direct SVC approach is both safe and effective, and should be considered especially in patients who have failed conventional ablation attempts from IVC approach.

Comparison of strategies for catheter ablation of left posterior fascicular ventricular tachycardia.

AIMS: Traditional ablation strategies including targeting the earliest Purkinje potential (PP) during left posterior fascicular (LPF) ventricular tachycardia (VT) or linear ablation at the middle segment of LPF during sinus rhythm are commonly used for the treatment of LPF-VT. Catheter ablation for LPF-VT targeting fragmented antegrade Purkinje (FAP) potential during sinus rhythm is a novel approach. We aimed to compare safety and efficacy of different ablation strategies (FAP ablation vs. traditional ablation) for the treatment of LPF-VT. METHODS AND RESULTS: Consecutive patients with electrocardiographically documented LPF-VT referred for catheter ablation received either FAP ablation approach or traditional ablation approach. Electrophysiological characteristics, procedural complications, and long-term clinical outcome were assessed. A total of 189 consecutive patients who underwent catheter ablation for LPF-VT were included. Fragmented antegrade Purkinje ablation was attempted in 95 patients, and traditional ablation was attempted in 94 patients. Acute ablation success with elimination of LPF-VT was achieved in all patients. Left posterior fascicular block occurred in 11 of 95 (11.6%) patients in the FAP group compared with 75 of 94 (79.8%) patients in the traditional group (P < 0.001). Fragmented antegrade Purkinje ablation was associated with significant shorter procedure time (94 ± 26 vs. 117 ± 23 min, P = 0.03) and fewer radiofrequency energy applications (4.1 ± 2.4 vs. 6.3 ± 3.5, P = 0.003) compared with the traditional group. One complete atrioventricular block and one left bundle branch block were seen in the traditional group. Over mean follow-up of 65 months, 89 (93.7%) patients in the FAP group and 81 (86.2%) patients in the traditional group remained free of recurrent VT off antiarrhythmic drugs (P = 0.157). CONCLUSION: Left posterior fascicular-ventricular tachycardia ablation utilizing FAP and traditional ablation approaches resulted in similar acute and long-term procedural outcomes. Serious His-Purkinje injury did occur infrequently during traditional ablation. The use of FAP ablation approach was associated with shorter procedure time and fewer radiofrequency energy applications, especially for non-inducible patients.

Cryoballoon ablation of persistent atrial fibrillation for de novo pulmonary vein isolation: a single-center follow-up study.

BACKGROUND: Pulmonary vein isolation (PVI) alone for persistent atrial fibrillation (PersAF) remains controversial. The characteristics of cryoballoon ablation (CBA) to treat PersAF and the blanking period recurrence are underreported. METHODS: This study retrospectively analyzed patients with PersAF undergoing second-generation CBA for de novo PVI. The post-procedural efficacy and survival analysis were compared between patients with different PersAF durations. The multivariate Cox regression analysis was used to detect the risk factors for recurrence. Early and long-term recurrence were analyzed relative to each other. RESULTS: A total of 329 patients were enrolled, with a median PersAF duration of 4.0 months (interquartile range: 2.0-12.0 months); 257 patients (78.1%) were male. Kaplan-Meier analysis of freedom from atrial fibrillation recurrence at 12, 24, and 30 months showed 71.0%, 58.5%, and 54.9%, respectively. Early PersAF had a relatively favorable survival rate and a narrow P-wave duration of restoring sinus rhythm compared with that of PersAF lasting more than three months (P < 0.05). The multivariate Cox regression analysis revealed that PersAF duration and left atrial anteroposterior diameter ≥ 42 mm were the risk factors for atrial fibrillation recurrence after CBA [hazard ratio (HR) = 1.89, 95% CI: 1.01-1.4, P = 0.042; HR = 3.6, 95% CI: 2.4-5.4, P < 0.001, respectively]. The blanking period recurrence predicted the long-term recurrence (P < 0.0001). CONCLUSIONS: CBA of PersAF had safety and efficacy to reach de novo PVI. The PersAF duration and left atrial size were risk factors for atrial fibrillation recurrence after CBA. Blanking period recurrence was associated with long-term recurrence.

Sequential versus optimized pulmonary vein isolation for paroxysmal atrial fibrillation: a pilot study.

PURPOSE: We aimed to investigate whether the sequence of wide circumferential pulmonary vein isolation (PVI) ablation had an effect on the acute reconnection or long-term effectiveness in patients with paroxysmal atrial fibrillation (AF). METHODS: One hundred consecutive paroxysmal AF patients, who were scheduled to accept PVI, were enrolled and randomized into two groups: (1) optimized group. Lesions were first applied to the anterior/posterior carina and the ridge between the left atrial (LA) appendage and the left pulmonary vein (PV). Then both circles were closed with continuous lesions. (2) Sequential group-continuous circular lesions were created counter-clockwise and started from the site of 6 o'clock. The primary endpoint was the freedom from non-blanking period recurrence of any atrial tachyarrhythmias lasting for 30 s or longer during the 1-year follow-up period after a single procedure. The secondary endpoint included safety endpoints, LA dwelling time, and fluoroscopy time/dose. RESULTS: Forty-nine patients in the optimized group and 48 patients in the sequential group were available for analysis. There was no difference between the AF-free rate of the optimized group and the sequential group (75.5% vs. 72.9%, p = 0.7715). Cox regression analysis found that acute reconnection had the potential to predict long-term recurrence at 1 year (Risk ratio 2.175, p = 0.0818). Both groups had similar safety endpoints, LA dwelling time, and fluoroscopy time/dose. CONCLUSIONS: Adjusting the ablation sequence of PVI by ablating the anterior/posterior carina and the ridge between the left PV and the LA appendage first did not improve 1-year AF-free rate for paroxysmal AF.

Predictors and Long-Term Outcome of Ablation of Discrete Pre-potentials in Patients With Idiopathic Ventricular Arrhythmias Originating From the Aortic Sinuses of Valsalva.

Background: The predictability and long-term outcome of the discrete pre-potential (DPP) of idiopathic ventricular arrhythmias (VAs) arising from the aortic sinuses of Valsalva (ASV) have not been fully identified. Methods: Of 687 consecutive patients undergoing ablation of outflow tract VAs, there were 105 (15.3%) patients with VAs originating from the ASV region who were included. Detailed mapping was performed within the ASV in all patients. Electrocardiographic, electrophysiological parameters, and long-term success rate were compared between patients with and without the DPPs. Results: A DPP was recorded in 67 of 105 (63.8%) patients, including 38 left sinus of Valsalva (LSV)-VAs (38/105, 36.2%) and 29 right sinus of Valsalva (RSV)-VAs (29/105, 27.6%). The patients with DPPs had wider QRS duration (152 ± 17 vs. 145 ± 14 ms, p < 0.001). The average of earliest activation time was significantly earlier in patients with DPPs (-38.6 ± 8.5 vs. -27.7 ± 5.7 ms, p < 0.001). Mean time from the first lesion to elimination of VAs was shorter in patients with DPPs (2.3 ± 2.1 s vs. 4.9 ± 1.0 s, p < 0.001). A stepwise logistic multivariable analysis identified only younger age as a significant predictor of DPP (age ≤ 35.5 years predicted DPP with 92.9% positive predictive value). During a follow-up duration of 42.5 ± 22.3 months, 63 (94.0%) patients with DPPs and 30 (78.9%) patients without DPPs remained free of recurrent VAs (p = 0.027). Conclusion: Discrete pre-potentials were observed in 63.8% of patients with VAs arising from the ASV. Ablation in patients with DPPs was associated with higher long-term success. DPPs were seen more commonly in younger (age ≤ 35.5 years) patients.

Safety and Efficacy Using the Second-Generation Cryoballoon in Patients With Atrial Fibrillation and a Common Ostium of Inferior Pulmonary Veins.

Background: Common ostium of inferior pulmonary veins (COIPV) is a kind of pulmonary vein variation. The safety and efficacy of COIPV isolation using the second-generation cryoballoon (CB) ablation remain unknown. Methods: A total of 10 patients with COIPV from a consecutive series of 1,751 patients with atrial fibrillation (AF) were included. Pulmonary vein isolation (PVI) was performed using the second-generation CB. Results: The prevalence of a COIPV was 0.57% in this study. PVI was achieved in all pulmonary veins (PVs) without the need for a touch-up. A segmental freeze strategy was applied for each inferior PV, respectively. The mean number of freeze cycles of inferior PVs was 1.4 ± 0.5 for the left inferior pulmonary vein (LIPV), and 2.0 ± 0.9 for the right inferior pulmonary vein (RIPV). Pulmonary vein potential (PVP) of RIPV could not be monitored in real-time in three cases. Eight of 10 patients (80%) were free from atrial arrhythmias without the use of antiarrhythmic drugs during a follow-up period of 23.6 ± 12.9 months. No procedure-related complications occurred in any of the 10 patients. Conclusions: Common ostium of inferior pulmonary veins is a rare but challenging PV variant. PVI with this unusual anatomic variation using the second-generation 28-mm CB is effective and safe.

Novel Clue to Locate Conduction Gaps in the Pulmonary Vein Isolation Ablation Line.

Background: Several methods have been reported for locating the conduction gap (CG) in the pulmonary vein isolation (PVI) ablation line. However, the value of the interval between far-field atrial potential (FFP) and pulmonary vein potential (PVP) remains unknown. Methods: Consecutive patients with a CG during observation on the table after PVI were included. The PVP, FFP, and the CG location were evaluated to develop a novel algorithm to identify the CG location in the left superior pulmonary vein. The performance of this novel algorithm was prospectively tested in a validation cohort of consecutive patients undergoing repeat PVI ablation. Results: A total of 116 patients with atrial fibrillation (AF) were recruited, 56 of whom formed the validation cohort. The interval between FFP and PVP of the left superior pulmonary vein was associated with the CG location, and an interval <5 ms predicted the presence of CG in the upper portion of the ostium with a sensitivity of 92.9% and a specificity of 96.9%. In the prospective evaluation, the interval was able to correctly predict the site of CG in 89.6% of cases. Conclusions: The interval between FFP and PVP is a novel and accurate index that can be used to predict the CG location in the left superior pulmonary vein. An far-field atrial potential and pulmonary vein potential (FFP-PVP) interval value of ≥5 ms could be used to exclude a CG in the upper portion of the ostium in the majority of patients undergoing AF ablation.

Outcomes of Different Ablation Approaches for Para-Hisian Accessory Pathway and Ablation Safety at Each Site.

BACKGROUND: This study describes the electrophysiologic characteristics of the para-hisian accessory pathway (AP), the outcome of different ablation approaches, and ablation safety at different sites. METHOD: A total of 120 patients diagnosed as para-hisian AP were included in this study. The electrophysiologic characteristics and outcomes at different ablation sites were analyzed. RESULTS: In total, 107 APs and 13 APs were diagnosed as right anteroseptal (RAS) and right midseptal (RMS), respectively. The significant ECG difference between RAS and RMS was lead III, which mainly manifested as positive and negative delta waves, respectively. Catheter trauma to AP was recorded in 21 of 120 (17.5%) patients. The recurrence rate of direct ablation at the "bumped" sites was higher than the conventional ablation method (37.5 vs. 14.1 %, p = 0.036). For RAS APs, there was no significant difference in the success rate between the inferior vena cava (IVC) and superior vena cava (SVC) approaches (76.6 vs. 73.3%, p = 0.63). The RAS was separated into three regions: (1) Site 1: superior part above the real "His" recorded site with far-field "His" potential; (2) Site 2 (true para-hisian): the site with near-field "His" potential; and (3) Site 3: inferior part below the biggest real "His" with far-field "His" potential. Mid-septal was defined as an area that is bounded anteriorly by His recording location and posteriorly by the roof of coronary sinus (CS) ostium. The incidence of atrioventricular (AV) conduction injury at different sites was as follows: 3 of 6 (50%) at Site 2, 4 of 13 (30.8%) at RMS, 7 of 34 (20.6%) at Site 3, and 3 of 46 (6.5%) at Site 1. Even if ablation was performed at the atrial side of the para-hisian region, the right bundle branch block (RBBB) was caused in 6 patients (5%). CONCLUSION: Ablation via IVC or SVC was comparative for para-hisian APs, but not for the noncoronary cusp (NCC) approach. The AV conduction injury risk ranks as follows: Site 2 > RMS > Site 3 > Site 1. RBBB could be caused while ablating at the atrial side, which could further demonstrate the His bundle longitudinal dissociation theory.

Pulmonary vein isolation implemented by second-generation cryoballoon for treating hypertrophic cardiomyopathy patients with symptomatic atrial fibrillation: a case-control study.

BACKGROUND: Atrial fibrillation (AF) is a generally acknowledged turning-point of the natural history of hypertrophic cardiomyopathy (HCM); however, data from the cryoballoon ablation (CBA) for AF in HCM patients are relatively scarce. The study aimed to evaluate the efficacy and safety of CBA in HCM patients with AF. METHODS: We retrospectively analyzed HCM patients among 1253 patients with symptomatic AF who underwent CBA for pulmonary vein isolation in a single center. The study analyzed the AF recurrence and assessed the CBA indexes, including nadir temperature, time-to-isolation, CBA failure, pulmonary vein potentials (PVPs), and redo procedure. RESULTS: A total of 108 patients were included (mean age: 59.0 ± 6.9 years), 27 patients (25%) had HCM, with the median follow-up duration of 25.5 months. The one-year AF-free rates were 79.0% vs. 63.0% (non-HCM vs. HCM), while the two-year AF-free rates were 77.8% vs. 55.1% [hazard ratio (HR) = 2.758, log-rank P = 0.024]. Patients with persistent AF had poor AF-free rates compared to those with paroxysmal AF (P < 0.001). The CBA failure was the most common in the right inferior pulmonary veins, which had the lowest PVPs. Multivariate Cox regression analysis indicated that HCM and persistent AF were risk factors for AF recurrence (HR = 2.74, 95% CI: 1.29-5.79, P = 0.008; and HR = 3.97, 95% CI: 1.85-8.54, P < 0.001, respectively). CONCLUSIONS: The CBA can be effectively and safely used to treat HCM patients with symptomatic AF. The freedom from AF for HCM patients after CBA is relatively low compared to that for non-HCM patients.

Electrical isolation of the superior vena cava using second-generation cryoballoon in patients with atrial fibrillation.

BACKGROUND: The safety and efficacy of superior vena cava (SVC) isolation using second-generation cryoballoon (CB) ablation remain unknown. METHODS: A total of 26 (3.2%) patients with SVC-related paroxysmal atrial fibrillation (AF) from a consecutive series of 806 patients who underwent second-generation CB were included. Pulmonary vein isolation was initially achieved by CB ablation. If the SVC trigger was determined, the electrical isolation of SVC isolation was performed using the second-generation CB. RESULTS: Real-time SVC potential was observed in all patients. Isolation of the SVC was successfully accomplished in 21 (80.8%) patients. The mean number of freeze cycles in each patient was 2.1 ± 1.1. The mean time to isolation and ablation duration were 22.5 ± 14.2 seconds and 94.5 ± 22.3 seconds, respectively. A transient phrenic nerve (PN) injury was observed in five patients (19.2%). There were two patients (7.7%) experienced reversible sinus node injury during the first application. During a mean follow-up period of 13.2 ± 5.8 months, four patients (15.4%) had atrial arrhythmia recurrences. CONCLUSION: Isolation of SVC using the second-generation 28-mm CB is feasible when SVC driver during AF is identified. Vigilant monitoring of PN function during CB ablation of SVC is needed to avoid PN injury.

Safety and efficacy of superior vena cava isolation using the second-generation cryoballoon ablation in a canine model.

BACKGROUND: The safety and efficacy of superior vena cava (SVC) isolation (SVCI) using second-generation cryoballoon (CB) ablation remains unknown. METHODS: Electrical isolation of SVC was attempted using the second-generation CB ablation catheter in 14 canines. Ablation duration was randomized to either 90 s (7 canines) or 120 s (7 canines). SVC venography was performed to identify the SVC-right atrium (RA) junction. The 28-mm CB was positioned above SVC-RA junction. Repeat electrophysiological assessment in the live animals was conducted 40-60 days post-ablation, after which animals were euthanized for histological examination. RESULTS: Acute SVCI was successfully performed in all canines. No significant differences in numbers of freezes (1.7 ±â€¯0.8 vs. 1.5 ±â€¯0.5, p = 0.658), time to isolation (TTI) (24.3 ±â€¯8.1s vs. 22.7 ±â€¯9.0s, p = 0.297), temperature at isolation (-23.4 ±â€¯12.5 °C vs. -21.5 ±â€¯11.1 °C, p = 0.370), and nadir temperature (-51.2 ±â€¯6.2 °C vs. -53.3 ±â€¯7.0 °C, p = 0.195) were observed between the 90-s and 120-s groups. There were no procedural complications except one transient sinus bradycardia in the 120-s group. After ablation, animals survived for 51 ±â€¯5 days. Chronic SVCI was achieved in 6 of 7 (85.7%) SVCs in the 90-s group and 7 of 7 SVCs (100%) in the 120-s group (p = 0.299). Histological analysis revealed that a circumferential transmural lesion was achieved in all isolated SVCs. No sinus node (SN) and phrenic nerve injuries were observed. The minimum distance between ablation lesion and SN was 5.1 ±â€¯3.0 mm. CONCLUSIONS: The second-generation CB ablation catheter is both safe and effective in achieving SVC isolation in a canine model. Effective SVCI was found in the 90-s dosing strategy.

Long-term outcome of cryoballoon ablation versus radiofrequency ablation for focal atrial tachycardias originating from the pulmonary veins.

PURPOSE: We aimed to investigate the characteristics of focal atrial tachycardias (ATs) arising from the pulmonary veins (PVs), as well as the safety and long-term efficacy of cryoballoon (CB) versus radiofrequency (RF) ablation in this population. METHODS: Eighty-three patients with ATs arising from PVs from a consecutive series of 487 patients who underwent CB and RF ablation were retrospectively reviewed. Patients who had a prior history of atrial fibrillation (AF) were excluded. The AT origin was confirmed during the conventional electrophysiological study and activation mapping. The ablation approach was at the discretion of the operators. RESULTS: Thirty-five patients were managed with focal ablation, 25 were ablated with unilateral PV isolation (PVI), and the remaining 23 were performed with CB ablation. All procedures were successfully ablated. There was no significant difference in procedure time between CB group and RF focal group (43.7 ± 11.8 min vs. 45.8 ± 11.2 min, P = 0.121), whereas the fluoroscopy time in CB group was longer than in RF PVI group (10.1 ± 2.5 min vs. 8.4 ± 2.8 min, P < 0.001). There was 1 recurrence in CB group, 4 recurrences of AT in RF focal group, and 2 recurrence in RF PVI group (P = 0.643). Repeat ablation was performed in 6 of 7 patients. Seventy-eight patients were available for long-term follow-up. At a mean of 5.4 ± 4.6-year follow-up, 77 of 78 patients were free from AT without antiarrhythmic medication after 1.1 ± 0.3 procedures. No patient had procedural complications and developed AF during the follow-up period. CONCLUSIONS: CB ablation is an effective and safe tool to treat ATs originating from the PVs. The ATs originating from the PVs represent an isolated clinical process and are not likely to be the forerunner of a more diffuse process leading to the development of PV AF.

Ablation of ventricular arrhythmias with predominant monophasic "R" waves in precordial leads from the left sinus of Valsalva: Electrocardiographic and electrophysiologic characteristics.

BACKGROUND: While the left sinus of Valsalva (LSV) is a frequent origin of ventricular arrhythmias (VAs). Uncommonly, VAs with right bundle branch block (RBBB) morphology may be successfully terminated from the LSV. OBJECTIVE: We aimed to investigate the electrocardiographic and electrophysiologic characteristics of VAs with RBBB which were successfully eliminated from the LSV. METHODS: We identified patients with VAs successfully ablated from the LSV from January 2014 to December 2017 and compared electrophysiologic characteristics and ablation sites of those VAs with RBBB versus a control group of patients with left bundle branch block morphology. RESULTS: We identified 18 patients with RBBB and predominant "R" waves in the precordial leads. In 12 (66.7%) patients, a small "s" wave in lead V2 and positive "R" in the remaining pericardial leads could be seen. Overall, a single "V" potential was seen in 72.2% of patients in the study group, while discrete potentials were recorded in 80% of the patients in the control group. The majority (88.9%) of the VAs could only be terminated at the nadir of the LSV in the study group. After mean follow-up of 33 ± 14 months, 93.8% and 92% were free of VAs after initial ablation in study and control group, respectively (P = 0.99). CONCLUSION: Some VAs with predominant monophasic "R" wave in precordial leads could be terminated from LSV, especially a small "s" wave in lead V2 was recorded. The nadir of LSV is highly successful for RBBB VAs and single electrogram was recorded at the target for most of the cases.

Catheter ablation of supraventricular tachycardia in patients with dextrocardia and situs inversus.

BACKGROUND: Dextrocardia with situs inversus is a rare cardiac positional anomaly. Catheter ablation procedures performed in this set of patients have not been sufficiently reported. METHODS: A total of 10 patients with dextrocardia and situs inversus who received catheter ablation for supraventricular tachycardia (SVT) were included from a cohort of over 20 000 cases of catheter ablation for SVT in three centers from 2005 to 2016. All patients underwent electrophysiologic study and catheter ablation of SVT. Ablation targets were selected based on different tachycardia mechanisms with the primary endpoint of noninduction of tachycardia. RESULTS: The average age was 32.4 ± 5.6 years. Congenitally corrected transposition of great arteries (TGA) with situs inversus and D-looping of the ventricles and aorta (congenitally corrected TGA {I,D,D}) was found in four patients, while the other six patients exhibited mirror-image dextrocardia {I,L,L}. The mechanisms of SVT were atrioventricular nodal reentrant tachycardia in four patients, atrioventricular reentrant tachycardia in three, typical atrial flutter in one, intra-atrial reentrant tachycardia in one, and focal atrial tachycardia in one. Immediate procedural success was achieved in 9 out of 10 patients with no procedural complications. During a follow-up period of 6.3 ± 3.5 years on average, all patients remained free from recurrent tachycardia. CONCLUSIONS: For patients with dextrocardia and situs inversus, catheter ablation of SVT is safe and feasible. Differences in catheter maneuver and fluroscopy projection, along with difficulties in distorted anatomy are major obstacles for successful ablation.

Procedural findings and clinical outcome of second-generation cryoballoon ablation in patients with variant pulmonary vein anatomy.

INTRODUCTION: The procedural findings and clinical outcome of second-generation cryoballoon (CB2) ablation in patients with variant pulmonary vein (PV) anatomy have not been fully investigated. METHODS: A total of 424 consecutive patients who underwent PV isolation with CB2 were included. Computed tomographic (CT) scan was performed in all patients before the procedure. The study population was divided into common PV, accessory PV, and nonvariant PV groups according to the CT scan. Procedural findings and clinical outcome between the three groups were compared. RESULTS: Variant PV anatomy was observed in 118 of 424 (27.8%) patients. PV isolation was successfully achieved in all patients in three groups with low rates of need for touch-up ablation (P = 0.974). Total procedure time was longer in the accessory PV group compared with nonvariant PV group (53.7 ± 12.9 vs 49.5 ± 8.8 minutes; P < 0.001). More number of applications per patient were required in accessory PV group compared with the nonvariant PV and common PV groups (7.5 ± 2.1 vs 6.5 ± 1.6, P < 0.001; 7.5 ± 2.1 vs 6.8 ± 1.4, P = 0.027, respectively). No significant difference in phrenic nerve (PN) injury was observed between the three groups (P = 0.693). During mean follow-up duration of 16.1 ± 3.3 months, there was no significant difference in rates of atrial fibrillation (AF) recurrences in the three groups (13 of 43 common PV group, 21 of 75 accessory PV group, and 80 of 306 nonvariant PV group, P = 0.178). CONCLUSION: Variant PV patterns are common in patients undergoing ablation for drug-resistant AF. CB2 ablation appears to be a reasonable strategy in the setting of the variant PV anatomy with a small increase in procedure time and the number of cryoapplications.

Predictors of hemoptysis in the setting of pulmonary vein isolation using the second-generation cryoballoon.

INTRODUCTION: To assess the predictors of hemoptysis using second-generation cryoballoon (CB). METHODS: Thirty patients with hemoptysis after second-generation CB ablation and 60 age-, gender-, and body mass index-matched controls were recruited. Anatomic parameters were obtained from preprocedural cardiac computed tomography (CT). Pulmonary vein isolation was performed with 28-mm balloon using single 3-minute freeze technique. RESULTS: Clinical and procedural characteristics were similar between the groups. A shorter distance between left superior PV (LSPV) and left main bronchus (LMB) was associated with hemoptysis (7.8 ± 4.3 mm vs. 12.5 ± 3.5 mm, P < 0.001), whereas no significant difference in the distance between right superior PV (RSPV) and right main bronchus (RMB) was found between groups (11.9 ± 3.5 mm vs. 12.9 ± 4.6 mm, P = 0.089). Additionally, the mean thickness of the connective tissue interposed between RSPV and RMB was significantly thicker than that between LSPV and LMB in both groups (both P < 0.001). A stepwise logistic multivariate analysis identified only the LMB-LSPV distance as an independent predictor of hemoptysis (odd ratio [OR] 2.676; 95% CI 1.121-4.843, P < 0.001). A cutoff value ≤ 9.5 mm predicted hemoptysis after CB ablation with 93.8% sensitivity and 75.0% specificity. CONCLUSION: Hemoptysis is a relatively rare event following second-generation CB ablation. The bronchi location obtained from CT aids in identifying high-risk population for the complication.

Safety and efficacy of catheter ablation of ventricular arrhythmias with para-Hisian origin via a systematic direct approach from the aortic sinus cusp.

BACKGROUND: Catheter ablation of ventricular arrhythmias (VAs) originating from the para-Hisian region could be challenging because of a potential damage to atrioventricular conduction system. OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of catheter ablation of VAs originating from the para-Hisian region via a systematic direct approach from aortic sinus cusps (ASCs). METHODS: Twenty-one consecutive patients with VAs with para-Hisian origin were included. Electrophysiological mapping of the entire right ventricle was initially performed, and then retrograde ASC mapping was performed when the earliest ventricular activation was recorded in the His bundle region. Ablation was preferentially performed within ASCs in all patients. RESULTS: Radiofrequency energy delivery resulted in the elimination of VAs in 17 of 21 patients (81%). In the remaining 4 patients, radiofrequency application was initiated at the target site of the right ventricular septum around the His bundle region and clinical VAs were finally successfully eliminated without junctional rhythm in 2 of 4 patients. During a mean follow-up of 34.8 ± 11.3 months, 1 of the 19 acute successful patients had VA recurrence. No procedure-related complications occurred during ablation or follow-up. CONCLUSION: Catheter ablation of VAs originating from the para-Hisian region via a direct approach from ASCs may be safe and effective in most unselected patients.

Right atrial dual-loop reentrant tachycardia after cardiac surgery: Prevalence, electrophysiological characteristics, and ablation outcomes.

BACKGROUND: Right atrial (RA) dual-loop reentrant tachycardia has been described in patients who have undergone open heart surgery. However, the prevalence, electrophysiological (EP) substrate, and ablation outcomes have been poorly characterized. OBJECTIVE: The purpose of this study was to investigate the prevalence, EP substrate, and ablation outcomes for RA dual-loop reentrant tachycardia after cardiac surgery. METHODS: We identified all patients with atrial tachycardia (AT) after cardiac surgery. We compared EP findings and outcomes of those with RA dual-loop reentrant tachycardia to a control group of patients with RA macroreentrant arrhythmias in the setting of linear RA free-wall (FW) scar. RESULTS: Of the 127 patients with 152 postsurgical ATs, 28 of the ATs (18.4%) had RA dual-loop reentry and 24 of 28 (85.7%) had tricuspid annular reentry combined with FW incisional reentry. An incision length >51.5 mm along the FW predicted the substrate for a second loop. In 22 of 23 patients (95.7%) with initial ablation in the cavotricuspid isthmus, a change in the interval between Halod to CSp could be recorded, and 15 of 23 patients (65.2%) had coronary sinus activation pattern change. Complete success was achieved in 25 of 28 patients (89.3%) in the dual-loop reentry group and in 64 of 69 patients (92.8%) in the control group. After mean follow-up of 33.9 ± 24.2 months, 24 of 28 patients (85.7%) and 60 of 69 patients (86.95%) were free of arrhythmias after the initial procedure in the 2 groups, respectively. CONCLUSION: The prevalence of RA dual-loop reentry is 18.4% of ATs with prior atriotomy scar. A long incision should alert physicians to the possibility of a second loop at the FW. Halo and coronary sinus activation patterns provide important clues to circuit transformation.