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.

The pre-ablation triglyceride-glucose index predicts late recurrence of atrial fibrillation after radiofrequency ablation in non-diabetic adults.

BACKGROUND: Current prognostic risk scoring systems and biomarkers are routinely used as non-invasive methods for assessing late recurrence of atrial fibrillation (AF) in patients who have undergone radiofrequency catheter ablation (RFCA). This study aimed to investigate the predictive value of the triglyceride-glucose (TyG) index for late AF recurrence after RFCA in non-diabetic patients. METHODS: In total, 275 patients with AF who underwent RFCA at the Fuwai hospital (Beijing, China) between January 2016 and December 2018 were enrolled in this study. During follow up, patients were divided into late and non-late AF recurrence groups, based on whether they had experienced late AF recurrence determined by electrocardiography (ECG) examine or 48 h Holter monitoring. The TyG index was calculated using the following equation: ln [fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2]. RESULTS: During a median follow-up of 26.1 months, late AF recurrence event rates significantly increased in the highest TyG index tertile group (tertile 3) compared to the lowest group (tertile 1) (54% versus 12%, respectively; p < 0.001). The mean TyG index was higher in the late AF recurrence group compared to the non- late AF recurrence group (9.42 ± 0.6 versus 8.68 ± 0.70, respectively; p < 0.001). On multivariate Cox regression analysis, the pre-ablation TyG index was an independent risk factor for late recurrence of AF after RFCA (hazard ratio [HR] 2.015 [95% confidence interval (CI): 1.408-4.117]; p = 0.009). Receiver operating characteristic (ROC) curve analysis revealed that TyG index was a significant predictor of late AF recurrence after RFCA, with an area under the ROC curve (AUC) of 0.737 (95% CI: 0.657-0.816; p < 0.001). In addition, the AUC of left atrial diameter (LAD) was 0.780 (95%CI: 0.703-0.857, p < 0.001). Finally, the TyG index positively correlated with LAD (r = 0.133, p = 0.027), high sensitivity C-reactive protein (r = 0.132, p = 0.028) and N-terminal pro B-type natriuretic peptide (r = 0.291, p < 0.001) levels. CONCLUSIONS: An elevated pre-ablation TyG index was associated with an increased risk of late AF recurrence after RFCA in non-diabetic patients. The TyG index may be potentially useful as a novel biomarker for the risk stratification of late AF recurrence in non-diabetic 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.

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.

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.

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.

Clinical, electrocardiographic, and electrophysiological characteristics of left upper septal fascicular ventricular tachycardia.

Aims: We sought to investigate the clinical, electrocardiographic, and electrophysiological characteristics of left upper septal fascicular ventricular tachycardia (LUS-VT). Methods and results: Eleven consecutive patients with LUS-VT were identified among 196 patients with left fascicular ventricular tachycardia (VT). Clinical VTs presented as paroxysmal in 8 patients and incessant in 3 patients. Six patients had previous left posterior fascicular VT ablation history. All VTs had narrow QRS complexes with QRS duration of 101.1 ± 9.2 ms. The frontal QRS axis was normal or right deviation. Precordial morphology was either right bundle branch block type or similar to that of sinus rhythm. A retrograde His with H-V interval of 21.9 ± 7.2 ms was recorded during VT. The earliest Purkinje potential (PP) to QRS interval during VT averaged 35.7 ± 4.5 ms. Clear diastolic potentials (DPs) with high frequency and low amplitude were found in only one patient. Ten patients were managed successfully by 11 ablation sessions, and 1 patient declined ablation. Successful targets at the left upper septum were sites with the earliest PP (9 cases) or with DP (1 case) during VT. After ablation, 2 cases (10%) developed new left anterior hemiblock or incomplete left bundle branch block. No VT recurred during a median follow-up period of 3.2 (range 1.0-12.7) years. Conclusion: LUS-VT presented as narrow QRS complex tachycardia. Some LUS-VTs occurred after ablation targeting left posterior fascicular VT. The VTs can be managed successfully by focal ablation at the left upper septum with a mild risk of fascicular injury.

Electrocardiographic and electrophysiologic differentiation between atriofascicular, long atrioventricular, and short atrioventricular decrementally conducting accessory pathways.

Aims: We aimed to examine the electrocardiographic and electrophysiologic characteristics of anterograde-conducting decremental accessory pathways (DAP) and to identify surrogate criteria to distinguish short atrioventricular (SAV) DAP from atriofascicular (AF) AP and long atrioventricular (LAV) DAP. Methods and results: We identified all patients with DAPs and analysed electrocardiographic and electrophysiologic characteristics. Distal insertion sites were examined using existing criteria, including V-H interval, ventricular activation at the right ventricular apex, and around tricuspid annulus during antidromic atrioventricular re-entrant tachycardia (A-AVRT) or complete pre-excitation and evaluated the AV node-like properties according to the response to adenosine and radiofrequency ablation. Out of 45 patients with DAPs, 28 (62.2%) had SAV-DAP (13 with definite AF-AP, 2 with definite LAV-DAP, 2 indeterminate). In all, 50% of SAV-DAPs and 53.3% of AF-AP/LAV-DAPs had 'rS' pattern in lead III. Longer QRS duration (159.9 ± 17.4 ms vs. 139.2 ± 14.3 ms, P < 0.0001) during full pre-excitation or A-AVRT differentiated SAV-DAP from AF-AP. The QRS-V(His) interval was longer for those with SAV-DAP compared vs. AF-AP/LAV-DAP (45.3 ± 2.4 ms vs. 22.9 ± 2.5 ms, P < 0.0001) and a cut-off value of 33.0 ms differentiated the two (sensitivity 81.3%, specificity 87.5%). Conclusion: The majority of the SAV-DAPs are located at the TA free wall. An 'rS' pattern in lead III is frequently seen in SAV-DAP as well as AF-AP/LAV-DAPs. Measuring the QRS-V(His) interval would be helpful to distinguish SAV-DAP from AF-AP/LAV-DAP.

Pulmonary vein isolation with real-time pulmonary vein potential recording using second-generation cryoballoon: Procedural and biophysical predictors of acute pulmonary vein reconnection.

OBJECTIVE: The study sought to evaluate the procedural and biophysical factors related to acute pulmonary vein isolation (PVI) guided by real-time pulmonary vein (PV) potential recordings. METHODS: A total of 180 consecutive patients with drug-resistant atrial fibrillation (AF) undergoing CB2 (second-generation version of cryoballoon) ablation were enrolled. Real-time monitoring of PV potentials was obtained using an inner lumen spiral mapping catheter. RESULTS: Acute isolation was achieved in all PVs without touch-up ablation. Real-time assessment of PV disconnection was possible in 611 of 711 (85.9%) PVs. A total of 617 (86.8%) PVs were isolated during the initial freeze. Longer time cycle integration (TCI) (TTI * freeze cycle, TCI) (254.6 ± 112.8 seconds vs 74.1 ± 59.7 seconds, P < 0.001), time to isolation (TTI) (94.3 ± 34.0 seconds vs 46.3 ± 26.2 seconds, P < 0.001), higher nadir temperature (-45.5 ± 5.3°C vs -50.4 ± 5.5°C, P < 0.001), longer time to -40°C (77.3 ± 22.7 seconds vs 55.7 ± 23.2 seconds, P < 0.001), faster interval rewarming time at 0°C (9.4 ± 4.3 seconds vs 12.4 ± 4.9 seconds, P = 0.008), and total balloon rewarming time (38.1 ± 11.6 seconds vs 47.7 ± 14.0 seconds, P = 0.003) were observed in PVs with acute reconduction. TTI ≤ 65 seconds predicted absence of acute reconnection with 84.2% sensitivity and 75.7% specificity, whereas TCI ≤ 119 seconds presented 94.7% sensitivity and 80.2% specificity. At a mean follow-up of 4.7 ± 1.4 months, 82.2% of patients were free of AF. None of those with PV reconnections suffered from AF recurrences. CONCLUSIONS: The ablation using CB2 is effective in achieving acute PVI. Real-time assessment of PVI could be achieved during CB application in 86% of PVs. The incidence of spontaneous PV reconnection is very low, observed in just 3% of isolated PVs. TTI ≤ 65 seconds and TCI ≤ 119 seconds predicted absence of acute PV reconnection. Although they may identify effective cryoapplications in the acute phase, their performance still needs to be verified in the long term.

"Crosstalk" technique: A comparison between two generations of cryoballoon catheter.

INTRODUCTION: The "Crosstalk" technique: if pulmonary vein isolation (PVI) of the superior one is not achieved due to a gap in the inferior part, it could be done during inferior vein cryoablation. This maneuver minimizes the total energy delivery time and number of lesions. We aimed to correlate the likelihood of crosstalk phenomenon with certain anatomic characteristics. METHODS: A total of 676 patients undergoing a first ablation procedure for paroxysmal or persistent atrial fibrillation (470 first-generation cryoballoon [CB] and 206 second-generation CB) between June 2014 and December 2016 were included. RESULTS: "Crosstalk" phenomenon occurred in 32 patients (18 first-generation CB, 14 second-generation CB). Compared to 54 control patients without crosstalk, the angle between left superior pulmonary vein (LSPV) and left atrial (LA) roof-plane, left pulmonary common ostia were significant parameters associated with crosstalk (odds ratio [OR] = 1.20, ±95% confidence interval [CI]: 1.11-1.31, P < 0.001; OR = 5.67, ±95% CI: 1.08-28.69, P = 0.04). As for angle between LSPV and LA roof-plane, the cut-off value was 28.68° with a sensitivity of 72.22%, a specificity of 81.25%, and an area under the receiver operating characteristic curve of 0.87 to predict the possibility of crosstalk technique application to get isolated in LSPV. Among the crosstalk group, there was no statistical difference between first-generation CB and second-generation CB in pulmonary anatomic characteristics. CONCLUSION: Crosstalk technique can be effective in patients with AF undergoing CB ablation using with both first and second-generation CBs. Anatomic characteristics predictive of crosstalk include a left common ostia and smaller angle between the LSPV and LA roof-plane.

Mapping and ablation of anteroseptal atrial tachycardia in patients with congenitally corrected transposition of the great arteries: implication of pulmonary sinus cusps.

AIMS: We sought to investigate focal atrial tachycardias (ATs) in patients with congenitally corrected transposition of the great arteries (ccTGA). METHODS AND RESULTS: We identified three cases of focal ATs with ccTGA from 2007 to 2015. The clinical findings, electrocardiography, electrophysiological features, and ablation were reported. All three cases had {S,L,L}-type ccTGA. The AT P waves shared the following features: narrow in width, positive in leads I and aVL, and negative/positive in lead V1. All ATs had focal activation pattern with early activation at the anteroseptal area, and further mapping demonstrated earliest atrial activation (EAA) inside the pulmonary sinus cusps (PSCs), especially the right PSC. In Cases 1 and 2, double potentials were recorded at the EAA sites. Conduction delay between the two potentials during atrial extrastimulus was observed. After successful ablation, the second potential during sinus rhythm was further delayed in Case 1 and was eliminated in Case 2. However, only one potential was recorded in Case 3. All three cases were successfully managed by ablating the sites with EAA, which preceded the P-wave onset by 60, 80, and 42 ms, respectively. During ablation, no junctional rhythm was observed. Incomplete left bundle branch block was induced during mapping in Case 1, but no other complications occurred. All patients were free from tachycardia during follow-up periods of 36, 7, and 5 months, respectively. CONCLUSION: Anteroseptal AT in patients with ccTGA could be eliminated by ablation inside the PSC.

Frequency of fractionated ventricular activation and atrial/ventricular electrogram amplitude ratio at successful ablation target of accessory pathways in patients with Ebstein's anomaly.

INTRODUCTION: Knowledge about local electrogram and atrial/ventricular electrogram amplitude ratio (A/V ratio) at the true atrioventricular ring for successful ablation of accessory pathways (APs) in patients with Ebstein's anomaly is limited. METHODS: Twenty-two adults with Ebstein's anomaly and APs were managed by 24 sessions of radiofrequency catheter ablation (RFCA). A right atrial/ventricular angiogram with or without 3-dimensional electroanatomic mapping was performed to delineate the true atrioventricular ring and atrialized right ventricle (ARV). Electrograms of successful targets were analyzed. For each right-sided AP target, 2 AP targets matched by location and conduction property from normal hearts were selected as controls, and their A/V ratios were compared. RESULTS: In 32 right-sided APs of all 22 patients, local ventricular activation at successful site presented as normal electrogram in 14, fractionated ventricular electrogram (FVE) in 16, and double ventricular potentials in 2. The bipolar voltage of ARV was markedly lower than in normal hearts. The A/V ratio at the successful target was significantly higher in APs with FVE than in control (1.64 ± 1.34 vs. 0.47 ± 0.19, P < 0.01), and was similar in APs with normal ventricular electrogram and in the control (0.38 ± 0.15 vs. 0.46 ± 0.15, P = 0.1726). The A/V ratio at the successful target with double ventricular potentials (after surgical correction) was 0.30 ± 0.20. All APs were successfully ablated without complications. CONCLUSIONS: In patients with Ebstein's anomaly, FVE was found in 50% of the successful targets of APs. High A/V ratio at successful sites with FVE and normal A/V ratio at targets with normal ventricular electrogram can facilitate target recognition and ablation.

Electrophysiological Characteristics and Radiofrequency Catheter Ablation of Accessory Pathway Connecting the Right Atrial Appendage and the Right Ventricle.

BACKGROUND: The accessory pathway (AP) connecting the right atrial appendage (RAA) and the right ventricle (RV) is rare. OBJECTIVE: We sought to investigate the feature of the AP connecting the RAA and the RV and the efficacy of radiofrequency catheter ablation via the endocardial access. METHODS: We retrospectively analyzed 14 consecutive patients with 14 APs connecting the RAA and the RV managed by 15 procedures between January 2003 and December 2014. RESULTS: Ten patients presented as preexcitation during sinus rhythm. All APs had retrograde conduction. None had either antegrade or retrograde decremental conduction property. Ablation targeting the sites at the tricuspid annulus failed in all patients. They were successfully managed by ablating the atrial insertion sites with a median of 10.5 (range 5-28) radiofrequency applications. Electrograms at the successful target showed high amplitude atrial electrogram and low amplitude or no ventricular electrogram. The atrial insertion sites were at the floor of the RAA in 10 patients and inside the lower lobe of the RAA in the remaining 4 patients. The shortest distance between the successful target and the tricuspid annulus in the right anterior oblique projection was 19.7 ± 4.0 mm. There were no complications or recurrences during a median follow-up period of 4.3 (range 0.2-11.8) years. CONCLUSION: The APs connecting the RAA and the RV had typical conduction properties. The atrial insertion site favored the floor and the lower lobe of the RAA. Ablation targeting the atrial insertion sites was effective and safe, albeit multiple radiofrequency applications were needed.

Pulmonary Vein Isolation Using the First-Generation Cryoballoon Technique in Chinese Patients.

BACKGROUND: Cryoballoon ablation is an alternative for the treatment of atrial fibrillation (AF). We assess the relationship among pulmonary vein (PV) electrophysiology, balloon temperature, and persistent PV isolation (PVI), and report procedural properties, safety, and efficacy of this technique in a Chinese center for the first time. METHODS: A total of 70 patients with paroxysmal (n = 57) and persistent (n = 13) AF were consecutively enrolled. PVI was performed with cryoballoon catheter. Real-time recording of dissociation of PV potentials was attempted using a circumferential mapping catheter. RESULTS: Successful PVI was achieved in 274 of 282 (97.2%) PVs. Procedural duration was 115.2 ± 24.8 minutes and fluoroscopy time was 29.6 ± 8.9 minutes. Real-time PV potential recording was achieved in 232 (84.3%) PVs. Regarding time to isolation, a cut-off value of less than 60 seconds was predictive of persistent PVI with a sensitivity of 0.76 and specificity of 0.82 (area under curve = 0.835; P < 0.0001). The nadir balloon temperature was significantly lower in PVs without early reconduction (-46.3 ± 0.5°C vs -40.2 ± 1.3°C, P < 0.0001). However, there was an insignificant trend that the balloon temperature at isolation was higher in PVs without reconduction (-33.9 ± 0.7°C vs -36.4 ± 2.0°C, P = 0.14). The overall complication rate was 5.7%. After a median follow-up of 6.5 (range 3.2-14.9) months, 76% of patients were free of AF recurrence with a blanking period of 3 months. CONCLUSIONS: Real-time PV potentials can be recorded in most PVs. The time to isolation is predictive of the persistency of PVI. The nadir balloon temperature, not the balloon temperature at isolation, is significantly lower in PVs without reconduction.

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.

Focal atrial tachycardias originating from the aorta-mitral continuity: Anatomical and electrophysiological characteristics.

BACKGROUND: The aorta-mitral annulus conjunction (AMC) is an uncommon site of origin of focal atrial tachycardias (ATs). Hence, the electrophysiological and ablation target characteristics are poorly described. OBJECTIVE: The purpose of this study was to describe the characteristics of AMC ATs in detail. METHODS: The study enrolled 650 patients with ATs, 21 (3.2%) of whom had ATs originating from the AMC. A comprehensive evaluation, including electrocardiography, electrophysiology study, computed tomography scan, and intracardiac echocardiography, was performed. RESULTS: The majority (19, 90.5%) of ATs occurred spontaneously. The mean age of this group was 48.9 ± 21.6 years, with 12 being female (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. The local AMC potential differed from the commonly perceived annular potential and was characterized by a prominent A wave and a smaller V wave (atrial-to-ventricular ratio > 1). The angle of encroachment on the left atrial anterior wall, compressed by the left coronary cusp, was significantly smaller in the AMC ATs group than in the control group consisted of 40 patients who underwent coronary artery CT scans because of the chest pain but without atrial arrhythmias were randomly selected, which may have contributed to the arrhythmia substrate (141.7° ± 11.5° vs 155.2° ± 13.9°; P = .026). CONCLUSION: A new strategy for mapping AMC ATs has been introduced. The ablation target should have an atrial-to-ventricular ratio of >1.

A novel alternating second-generation cryoballoon or contact-force guided radiofrequency catheter ablation strategy for redo-ablation in patients with recurrent atrial fibrillation: a single-center experience.

BACKGROUND: Pulmonary vein (PV) reconnection after radiofrequency (RFC) or cryoballoon (CB) pulmonary vein isolation (PVI) is common. METHOD: We report a single-center experience of 156 patients who underwent a redo procedure-ablation strategy for recurrent atrial fibrillation (AF) in a reverse sequence after a failed index RFC or CB PVI. RESULTS: A total of 60 patients after index CB PVI underwent RFC-redo ablation (CB-RFC redo), and 96 patients after index RFC PVI underwent CB-redo ablation (RFC-CB redo). During the redo procedure, the proportion of patients with PV reconnection was lower after index CB PVI procedure compared with the proportion of patients after index RFC PVI (88.3% versus 98.9%, p = 0.01). Additionally, a mean number of 1.50 ± 0.8 PVs/patient were reconnected after index CB PVI, compared with 3.36 ± 0.9 PVs/patient after index RFC PVI (p = 0.001). Patients after index RFC PVI frequently presented with ≥ 3 reconnected PVs, compared with index CB PVI (70.8% vs 10%, p < 0.001). At a 2-year follow-up, 43 patients (27.6%) developed recurrence after redo ablation, with a similar AF-free outcome (CB-RFC redo:73.3% vs RFC-CB redo: 71.9%, p = 0.873). In the multivariate analysis, persistent AF (HR = 2.107, 95% CI: 1.085-4.091, p = 0.028) and early AF recurrence after the initial ablation (HR = 2.431, 95% CI: 1.279-4.618, p = 0.007) were independent predictors of AF recurrence. CONCLUSIONS: The extent and distribution of PV reconnections were different after index RFC and CB PVI procedures. Alternating CB or RFC ablation technique strategy is effective with a similar long-term outcome, and it may be an appropriate option for repeated AF ablation.

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.