Circumferential Pulmonary Vein Research Articles

The efficacy of ablation based on the combined use of the dominant frequency and complex fractionated atrial electrograms for non-paroxysmal atrial fibrillation

BackgroundThis study aimed to evaluate an approach for an endpoint of non-inducibility using a combined high-dominant frequency (DF) and continuous complex fractionated atrial electrogram (CFAE) ablation following circumferential pulmonary vein isolation (PVI) in a sequential fashion, including linear ablation as compared to PVI alone. Methods and resultsA total of 84 non-paroxysmal patients with atrial fibrillation (AF) were investigated retrospectively. The AF patients were divided into two groups: patients with PVI following a combined high-DF and continuous CFAE ablation with linear ablation (substrate modification group, n=59) and those with PVI alone (n=25). DF sites of ≥8Hz and then continuous CFAE sites defined by fractionation intervals of ≤50ms were modified after PVI. The ablation endpoint was non-inducibility. Atrial tachyarrhythmias (ATs) could not be induced in 54 of 59 (92%) patients after a sequential ablation, and in 18 of 25 (64%) with PVI alone. The ATs freedom without antiarrhythmic drugs in the substrate modification group was significantly greater than that in those with PVI alone after 1 procedure during 12 months of follow-up (78.6% vs. 53.8%, log-rank test p=0.039). ConclusionThis sequential approach using a substrate based ablation was associated with a better clinical long-term outcome as compared to PVI alone.

Comparison of circumferential pulmonary vein anatomy mapping guided by 3D mapping versus a mesh mapping catheter

ObjectiveCatheter-based pulmonary vein isolation (PVI) is an established therapy for paroxysmal atrial fibrillation. The high-density mesh mapper (HDMM) guides circumferential PV-atrium isolation without the 3D electroanatomic mapping. This study aims to compare circumferential pulmonary vein (CPV) anatomy mapping between guiding by a 3D mapping system and the HDMM. MethodsForty-four consecutive patients with paroxysmal atrial fibrillation were scheduled for a first procedure for PVI. A CPV ostial anatomy map guided by HDMM was set up in the CARTO system while the operator was blinded to the CARTO screen. Then CARTO-guided ipsilateral PV maps were obtained and PVI was performed. This established another set of CPV ostial anatomy maps. The differences between the two mapping images were compared and analyzed. ResultsAll 176 PVs in 44 patients could be mapped by both HDMM and CARTO. About 44.9% of the PV ostial anatomies were generally similar between the two different map images. The average point-to-point straight distance between the HDMM-guided map and the CARTO-guided map was 6.2 ± 1.4 mm. The area of the circumferential right PV (CRPV) in the HDMM map was larger than that in the CARTO map (P = 0.013). After a mean follow-up of 18.3 ± 4.3 months (6–24 months), 72.7% of patients (32/44) were free of atrial arrhythmia without anti-arrhythmic drugs (AADs). ConclusionCompared to the CARTO-guided CPV anatomy image, a highly similar figure could be achieved by mapping guided by the HDMM. (Clinical trial.gov number, ChiCTR-TNRC-11001390.)

Long-term outcomes of catheter ablation of atrial fibrillation in dilated cardiomyopathy

ObjectiveThe long-term outcomes, efficacy and safety of catheter ablation in atrial fibrillation (AF) patients with dilated cardiomyopathy (DCM) have not been reported previously. Methods and resultsForty nine patients with AF (59% longstanding persistent AF, LSP-AF) and DCM were enrolled. Circumferential pulmonary vein ablation (CPVA, paroxysmal AF), bidirectional block of lines and disappearance of complex fractionated atrial electrograms (CFAEs, persistent and LSP-AF) were the endpoints of the index and repeat procedures. Cumulative success rate reached 49% (mean, 1.4 procedures) during the first year, and dropped to 38% at median follow-up of 45months (range, 36–64months) for multiple procedures (mean, 1.9±0.8 [1–4]). Incidence of procedural complications was similar to that of conventional procedures. In multivariate analysis, LSP-AF (OR, 7.40 [95% CI, 1.42–38.34]; P=0.017) and larger left ventricular end-diastolic diameter (OR, 1.24 [95% CI, 1.01–1.52]; P=0.034) were significant independent predictors of recurrent atrial tachyarrhythmia (ATa). Compared with patients with ATa recurrence, those free from ATa had better New York Heart Association functional class, 6-minute walk distance and left ventricular ejection fraction during long-term follow-up compared with pre-ablation, but this improvement was not sustained beyond 3years. ConclusionIn patients with DCM, current commonly used ablation strategies including CPVA, linear ablation and CFAE ablation are not associated with long-term AF treatment success up to five years. Freedom from ATa is associated with improved heart failure during but not beyond 3years post ablation.

A case of paroxysmal atrial fibrillation with a non-pulmonary vein trigger identified by intravenous adenosine triphosphate infusion

A 54-year-old woman was referred to our institution with frequent chest discomfort and was diagnosed with drug-refractory paroxysmal atrial fibrillation. Radiofrequency catheter ablation (RFCA) was performed using a three-dimensional electroanatomic mapping system. After completion of left and right circumferential pulmonary vein isolation (CPVI), an intravenous bolus of adenosine triphosphate (ATP, 20mg) was administered to evaluate the electric reconduction between the pulmonary vein (PV) and left atrium (LA). Although no PV–LA reconduction was observed, atrial fibrillation (AF) was reproducibly induced. As the duration of AF was very short (<20s), no further RFCA to the LA was performed. One month later, the patient presented with frequent atrial tachyarrhythmias (ATs), and RFCA was repeated. Although no electric reconduction was observed in the left- or right-sided PVs, incessant ATs and AF were induced after an intravenous bolus administration of ATP. The earliest atrial activation site initiating ATs was consistently identified from electrodes positioned in the superior vena cava (SVC), and both ATs and AF were no longer inducible after electric isolation of the SVC. ATP-induced PV/non-PV ectopy may be a marker of increased susceptibility to autonomic triggers of AF and could potentially predict recurrent AF after CPVI.

Is the Atrial Neural Plexis a Therapeutic Target in Atrial Fibrillation?

Circumferential pulmonary vein isolation is the mainstay of atrial fibrillation (AF) ablation, but alternative approaches and techniques have been developed to improve the outcomes. One of these additional ablation targets are ganglionated plexi of the intrinsic cardiac autonomic system that contain a variety of sympathetic and parasympathetic neurons that communicate with the extrinsic cardiac autonomic nervous system. The ganglionated plexi of the heart do not serve as a simple relay station but could modulate the autonomic interaction between the extrinsic and intrinsic cardiac autonomic system. Intrinsic cardiac autonomic nerve activity is an invariable trigger of paroxysmal atrial tachyarrhythmia, including atrial fibrillation. Although multiple studies have shown that ganglionated plexi play an important role in initiating atrial fibrillation, there is no consensus on a standardized protocol for selecting target sites and determining how ganglionated plexi ablation can best be accomplished. Recent clinical trials have demonstrated the feasibility and efficacy of ganglionated plexi ablation in addition to pulmonary vein isolation, but novel technologies and strategies are necessary to improve the current ablation techniques in managing patients with atrial fibrillation. This review focuses on the relationship between atrial ganglionated plexi and atrial fibrillation and the potential benefits and limitations of ganglionated plexi ablation in the management of atrial fibrillation.

Feasibility and clinical efficacy of left atrial ablation for the treatment of atrial tachyarrhythmias in patients with left atrial appendage closure devices.

Left atrial appendage (LAA) closure devices have been introduced recently as an alternative for oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF). Because of potential overlap of ablation target areas and the previously implanted LAA closure device, as well as potential complications such as mechanical damage to the device, left atrial (LA) ablation remains a subject of debate in these patients. We report on the feasibility and clinical efficacy of LA ablation after implantation of LAA closure devices. Eight patients (6 men; age 69 ± 8 years) with symptomatic paroxysmal AF (n = 5) or persistent AF (mean CHA2DS2-VASc score 3.6 ± 0.7, mean HAS-BLED score 3.6 ± 1.5) and previously implanted WATCHMAN (7 patients) or AMPLATZER Cardiac Plug (1 patient) LAA closure devices received radiofrequency-based LA ablation (4 via circumferential pulmonary vein isolation [CPVI], 4 via CPVI and additional LA linear lesions or complex fractionated atrial electrograms) after a mean of 201 days (range 41-756 days) after LAA closure. Successful LA ablation was achieved without device interference or periprocedural complications. After a mean of 503 days (range 113-1006 days), transesophageal echocardiography (TEE) was performed in all patients to assess for device-related complications. No device dislocation or leakage was observed. In 1 patient (12.5%), a device-related thrombus was found despite therapeutic OAC with dabigatran. Five patients (63%) remained in stable sinus rhythm, and no bleeding events or stroke occurred during a follow-up of 554 days (range 218-1006 days). LA ablation after LAA closure appears to be feasible. Device-related thrombus formation in 1 patient suggests the need for further TEE examinations after LA ablation after LAA closure device implantation.

Interatrial septal thickness is associated with the extent of left atrial complex fractionated atrial electrograms and acute procedural outcome in patients with persistent atrial fibrillation.

The interatrial septal thickness (IAST) reflects the changes of the atrial wall in patients with atrial fibrillation (AF). Complex fractionated atrial electrograms (CFAEs) were consistently positioned on the interatrial septum, especially in the remodelled left atrium (LA). We sought to characterize the relationship between IAST and LA CFAE area, as well as the acute procedural and clinical outcomes of catheter ablation in persistent AF patients. This study included 71 patients who underwent catheter ablation for drug-refractory persistent AF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by LA and right atrial CFAE-guided ablation. Interatrial septal thickness was measured 1 cm inferior to the fossa ovalis on cardiac computed tomography (CT). The extent of LA CFAEs was assessed by CFAE area and index (CFAE area/LA surface area × 100). Patients were grouped into tertiles according to the value of IAST. The mean IAST of the first, second, and third tertile was 4.69 ± 0.79, 6.44 ± 0.45, and 9.12 ± 1.42 mm, respectively (P < 0.001). The mean CFAE areas (5.6 ± 6.9, 18.5 ± 20.3, and 24.3 ± 26.6 mm(2), P = 0.005) and CFAE indexes (3.1 ± 4.2, 9.2 ± 10.7, and 11.8 ± 15.3, P = 0.025) in LA were significantly different among the three groups. More patients in the highest IAST tertile did not terminate AF during catheter ablation (12.5% vs. 26.1% vs. 37.5%, P = 0.048). Interatrial septal thickness measured by cardiac CT is associated with the extent of CFAE area within the LA and is related to acute procedural success of catheter ablation. These findings suggest that IAST reflects the degree of atrial substrate and remodelling in patients with persistent AF.

FIBRILLATION NUMBER BASED ON WAVELENGTH AND CRITICAL MASS IN PATIENTS WHO UNDERWENT RADIOFREQUENCY CATHETER ABLATION FOR ATRIAL FIBRILLATION

Introduction: It is known that characteristic length, the inverse of conduction velocity, and the inverse of refractory period determine vulnerability to fibrillation (fibrillation number) in in-silico or ex-vivo models. The purposes of this study were to validate the accuracy of the fibrillation number (FibNAF) by in silico atrial modeling and its clinical application in patients with atrial fibrillation (AF) who underwent radiofrequency catheter ablation (RFCA). Methods: We compared the maintenance duration of AF at various FibNAF values using in-silico 2-dimensional bidomain atrial modeling. Fibrillation wave dynamics simulation was performed for 16 different values of FibNAF determined by randomly generated characteristic length, action potential duration, and conduction velocity. For clinical validation of FibNAF, we compared post-procedural AF inducibility and induction pacing cycle length (iPCL) depending on FibNAF among 60 patients (male 72%, 54±13 years old, paroxysmal AF 82%) who underwent circumferential pulmonary vein isolation (CPVI) for AF rhythm control. Clinical FibNAF was calculated by echocardiographically measured LA dimension, the inverse of conduction velocity and the inverse of atrial refractory period. Results: Computational simulation results showed a positive correlation between AF maintenance duration and FibNAF (R=0.90, p Conclusions: FibNAF based on critical mass and wavelength correlates well with AF maintenance in computational modeling and clinical AF inducibility after CPVI. Additional clinical and computational research is needed to ensure that FibNAF is applicable to individual patients.

0170: Long-term success with magnetic navigation catheter ablation in patients with persistent and longstanding persistent atrial fibrillation

Different techniques in catheter ablation (CA) of persistent (Pers) and longstanding (LS) Pers AF have been described with variable outcomes. We report long-term results in a series of Pers AF patients who underwent CA with magnetic navigation (MN). We prospectively included 50 patients (pts; 43 males; 61±10 y) referred for CA of Pers AF. Pers and LS Pers AF were defined according to published guidelines. Freedom from AF is defined as the absence of symptomatic or ECG/Holter documented AF after ablation. All pts underwent stepwise CA using MN: circumferential pulmonary veins isolation, bi-atrial complex fragmented electrograms ablation, roof ± left isthmus ± cavo-tricuspid isthmus lines. Atrial tachycardia (AT) occurring during CA were also targeted. Total duration of AF history was 56±42m (range 4 m-12 y, median 48m). Mean duration of continuous AF was 8±12m (range 1-84m, median 5.5m; 18% LS and 82% Pers AF). AF was lone in 50%. LA size was 30±5cm 2 , CT-scan volume 139±51ml. Procedures’ duration was 256±56 minutes with a fluoroscopy time of 13±5 min. RF time was 47±27 min. AF stopped without electrical cardioversion in 17 pts (34%; sinus rhythm in 8 and AT in 9). A redo CA for recurring AF was performed in 6 pts (12%). Complications (4 pts) resolved w/o sequellae: acute coronary syndrome (1), pericardial effusion (1), AV fistula (1) and intraalveolar haemorrhage (1). After 19.9±9.5m (range 6-40, median 17.5m), with 1.1 procedures/pt, 40 pts (80%) had no AF recurrence, of which 28 were off AAD and 12 remained on AAD. Incidence of postablation AT was 12% (6/50). Magnetic navigation for Pers AF ablation yields excellent (80%) long-term (20m) prevention of AF recurrence (figure next page). Abstract 0170 – Figure: AF-free survival

Clinical implications of and factors influencing dissociated pulmonary vein potentials

BackgroundFactors influencing dissociated pulmonary vein (PV) potentials (DPVPs) in atrial fibrillation (AF) patients undergoing circumferential PV isolation have not been investigated. Furthermore, the clinical implications of such DPVPs remain controversial. MethodsCircumferential PV isolation as a first ablation procedure was performed in 688 consecutive patients with AF (460 men; mean age, 58.9±10.5 years). The clinical implications of and factors influencing DPVPs were evaluated. ResultsAcute PV isolation was achieved in 679 (98.7%) patients. A total of 578 (42.6%) ipsilateral PVs with DPVPs were documented in 378 (55.7%) patients (DPVPs group). Multivariate analysis revealed that male gender [odds ratio (OR): 1.894; 95% confidence interval (CI): 1.344–2.667; p<0.001] and paroxysmal AF (OR: 1.715; 95% CI: 1.182–2.488; p=0.005) were independent factors for DPVPs. The incidence of acute and intraoperative PV reconnection (PVR) was higher in the DPVPs group than in the non-DPVPs group (33.1% vs. 17.9%; p<0.001 and 44.4% vs. 28.2%; p<0.001). After the first procedure, 244 (65.6%) DPVPs-group patients and 168 (56.4%; p=0.015) non-DPVPs group patients were free from AF recurrence. During repeat procedures, PVR incidence was similar in the DPVPs group (81.8%) and non-DPVPs groups (83.3%; p=0.863). ConclusionMale gender and paroxysmal AF were independent risk factors for DPVPs in patients undergoing circumferential PV isolation. DPVPs had a significant impact on acute and intraoperative PVR. The outcomes of the first ablation procedure were better in patients with DPVPs.

Does isolation of the left atrial posterior wall improve clinical outcomes after radiofrequency catheter ablation for persistent atrial fibrillation?: A prospective randomized clinical trial

IntroductionAlthough posterior wall of left atrium (LA) is known to be arrhythmogenic focus, little is known about the effect of posterior wall isolation (PWI) in patients who undergo radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (PeAF). MethodsWe randomly assigned 120 consecutive PeAF patients to additional PWI [PWI (+), n=60] or control [PWI (−), n=60] groups. In all patients, linear ablation was performed after circumferential pulmonary vein isolation (PVI). Linear lesions included roof, anterior perimitral, and cavotricuspid isthmus lines with conduction block. In PWI (+) group, posterior inferior linear lesion was also conducted. Creatine kinase-MB (CK-MB) and troponin-T levels were measured 1day after RFCA. LA emptying fraction (LAEF) was assessed before and 12months after RFCA. ResultsA total of 120 subjects were followed for 12months after RFCA. There were no significant differences between two groups in baseline demographics and LA volume (LAV). The levels of CK-MB and troponin-T and procedure time were not significantly different between the groups. AF termination during RFCA was more frequently observed in PWI (+) than control (P=0.035). During follow-up period, recurrence occurred in 10 (16.7%) patients in PWI (+) and 22 (36.7%) in control (P=0.02). The change in LAEF was not significantly different between the groups. On multivariate analysis, smaller LAV and additional PWI were independently associated with procedure outcome. ConclusionsPWI in addition to PVI plus linear lesions was an efficient strategy without deterioration of LA pump function in patients who underwent RFCA for PeAF.

Comparison of Radiofrequency Catheter Ablation of Drivers and Circumferential Pulmonary Vein Isolation in Atrial Fibrillation: A Noninferiority Randomized Multicenter RADAR-AF Trial

BackgroundEmpiric circumferential pulmonary vein isolation (CPVI) has become the therapy of choice for drug-refractory atrial fibrillation (AF). Although results are suboptimal, it is unknown whether mechanistically-based strategies targeting AF drivers are superior. ObjectivesThis study sought to determine the efficacy and safety of localized high-frequency source ablation (HFSA) compared with CPVI in patients with drug-refractory AF. MethodsThis prospective, multicenter, single-blinded study of 232 patients (age 53 ± 10 years, 186 males) randomized those with paroxysmal AF (n = 115) to CPVI or HFSA-only (noninferiority design) and those with persistent AF (n = 117) to CPVI or a combined ablation approach (CPVI + HFSA, superiority design). The primary endpoint was freedom from AF at 6 months post-first ablation procedure. Secondary endpoints included freedom from atrial tachyarrhythmias (AT) at 6 and 12 months, periprocedural complications, overall adverse events, and quality of life. ResultsIn paroxysmal AF, HFSA failed to achieve noninferiority at 6 months after a single procedure but, after redo procedures, was noninferior to CPVI at 12 months for freedom from AF and AF/AT. Serious adverse events were significantly reduced in the HFSA group versus CPVI patients (p = 0.02). In persistent AF, there were no significant differences between treatment groups for primary and secondary endpoints, but CPVI + HFSA trended toward more serious adverse events. ConclusionsIn paroxysmal AF, HFSA failed to achieve noninferiority at 6 months but was noninferior to CPVI at 1 year in achieving freedom of AF/AT and a lower incidence of severe adverse events. In persistent AF, CPVI + HFSA offered no incremental value. (Radiofrequency Ablation of Drivers of Atrial Fibrillation [RADAR-AF]; NCT00674401)

Variability of P-wave morphology predicts the outcome of circumferential pulmonary vein isolation in patients with recurrent atrial fibrillation

IntroductionSevere atrial structural remodeling may reflect irreversible damage of the atrial tissue in patients with atrial fibrillation (AF) and is associated with changes of P-wave duration and morphology. Our aim was to study whether variability of P-wave morphology (PMV) is associated with outcome in patients with AF after circumferential PV isolation (CPVI). Methods and results70 consecutive patients (aged 60±9years, 46 men) undergoing CPVI due to symptomatic AF were studied. After cessation of antiarrhythmic therapy, standard 12-lead ECG during sinus rhythm was recorded for 10min at baseline and transformed to orthogonal leads. Beat-to-beat P-wave morphology was subsequently defined using a pre-defined classification algorithm. The most commonly observed P-wave morphology in a patient was defined as the dominant morphology. PMV was defined as the percentage of P waves with non-dominant morphology in the 10-min sample. At the end of follow-up, 53 of 70 patients had no arrhythmia recurrence. PMV was greater in patients without recurrence (19.5±17.1% vs. 8.2±6.7%, p<0.001). In the multivariate logistic regression model, PMV≥20% (upper tertile) was the only independent predictor of ablation success (OR=11.4, 95% CI 1.4–92.1, p=0.023). A PMV≥20% demonstrated a sensitivity of 41.5%, a specificity of 94.1%, a PPV of 96.7%, and an NPV of 34.0% for free of AF after CPVI. ConclusionsWe report a significant association between increased PMV and 6-month CPVI success. PMV may help to identify patients with very high likelihood of freedom of AF 6-months after CPVI.

Abstract 11670: Presence of Dissociated Pulmonary Vein Activity After Isolation Depends on Fibrillatory Excitation in Pulmonary Vein

Background: Circumferential pulmonary vein (PV) isolation has been widely accepted as catheter ablation for atrial fibrillation (AF). Dissociated PV activity (DPVA) may appear after PV isolation, however, the electrophysiological property and clinical implication of DPVA have not been revealed. Methods and Results: The study subjects were consecutive 37 patients (62±8 years, 28 men) with drug-refractory AF who underwent successful PV isolation. Electrophysiological property of left atrium (LA) and PV during and after PV isolation were investigated. Excluded 21 PVs without LA-PV connection before procedure, all of 112 PVs with successful isolation were analyzed. DPVA appeared in 14 PVs (13%) after PV isolation, from left superior PV in 7 (50%), right superior PV in 5 (36%) and left inferior PV in 2 (14%). Mean cycle length (CL) of DPVA was 5180±3080 ms. DPVA appeared in 9 of 37 PVs (24%) without existence of AF, but in 5 of 75 PVs (7%) with existence of AF during procedure (P=0.008). There was the tendency that the CL of DPVA was shorter with existence of AF compared to that without existence of AF (3792±1815 vs. 6682±3041 ms, P=0.08), and the suppression of DPVA was observed by over drive pacing inside of PV with PV capture in several cases. There was not significant relationship between the presence of DPVA and AF recurrence with 2-month blanking period after PV isolation. Conclusions: The presence of DPVA after PV isolation depended on the existence of AF during procedure, but was not significantly related to the AF recurrence after PV isolation. The long CL and suppressive maneuver with PV over drive pacing suggested the vulnerability of DPVA. Thus, these findings suggest that passive and/or spontaneous fibrillatory excitation in PV might suppress the automatic activity of myocardial sleeves in PV.

Abstract 18667: Impact of Direct Contact Force Measurement on Electrical Reconnections after Circumferential Pulmonary Vein Isolation for Atrial Fibrillation Using a Contact Force-Sensing Catheter

Purpose: To prospectively evaluate the incidence of pulmonary vein (PV) reconnections (PVRs) and identify predictors of PVRs after circumferential PV isolation (CPVI) using a contact force (CF)-sensing ablation catheter. Methods: Sixty-five patients (51-males; 61±10 years) undergoing an initial CPVI were studied. Both the right and left CPVI lines were divided into 12 segments and multiple regression models were used to predict PVRs in the four regions (each including 6 segments), the anterior and posterior RPVs and LPVs (A-RPVs, P-RPVs, A-LPVs, and P-LPVs). Each radiofrequency application was delivered with 15-30W for &lt;30s along the P-LPVs and 30-40W for 40-60s along the others. Results: In 63 reconnected gaps, the right-PVs had more gaps in the anterior and posterior carina, while the left-PVs had more in the posterior carina than elsewhere, respectively (P&lt;0.05). The P-RPVs and P-LPVs had significantly more gaps than the A-LPVs (17 A-RPVs, 21 P-RPVs, 6 A-LPVs, and 19 P-LPVs; P&lt;0.05). The mean CF in the A-RPVs and P-RPVs (odds ratios (ORs), 0.916 and 0.854; P=0.014 and &lt;0.001, respectively) and Force-Power-Time Index (FPTI) in the A-LPVs (OR, 0.99; P=0.012) were significant negative predictors of PVRs. According to the receiver operating characteristics analysis, at optimal cutoffs of mean CFs of 18g (A-RPVs) and 12g (P-RPVs), and FPTI of 36,737g.W.s (A-LPVs), the sensitivity and specificity for predicting PVRs were 81.3% and 61.9%, 71.3% and 52.9%, and 58.6% and 100%, respectively. Conclusions: The carina regions can be common sites for PVRs despite a higher CF and FPTI. An optimal CF and FPTI may be needed to prevent PVRs during an initial CPVI, especially in the RPVs and A-LPVs.

Incidence and clinical characteristics of transient ST-T elevation during transseptal catheterization for atrial fibrillation ablation.

Transient ST-T elevation (STE) is a rare complication that occurs during transseptal catheterization. This study aims to delineate the incidence and characteristics of transient STE during transseptal catheterization for atrial fibrillation (AF) ablation. Consecutive patients who underwent fluoroscopy-guided transseptal catheterization for circumferential pulmonary vein radiofrequency ablation in Beijing An Zhen Hospital from January 2006 to January 2013 were enrolled in this study. Out of 2965 patients with a total of 3452 transseptal catheterization procedures, 13 patients (0.38%, mean age 57 ± 8, 6 female, 12 paroxysmal AF, mean left atrial diameter 35.4 ± 3.8 mm) had STE. ST-T elevation occurred after transseptal puncture in 10 patients and after pulmonary vein venography in three patients. Systolic blood pressure (129 ± 10 vs. 104 ± 20 mmHg, P < 0.001), diastolic blood pressure (78 ± 6 vs. 64 ± 11 mmHg, P < 0.001), and heart rate (83 ± 19 bpm vs. 64 ± 23 b.p.m., P = 0.022) significantly decreased when STE occurred. Eleven patients complained of chest pain, one patient complained of dizziness, and one patient had no symptoms. Patients recovered in about 4.6 min (2-10 min) with dopamine or fast saline drip. Catheter ablation of AF was completed in all the 13 patients without sequelae or other complications. Four of the 13 patients (30.8%) had recurrence of AF after a mean follow-up of 21.7 months. ST-T elevation is a rare complication associated with transseptal catheterization without sequelae. Catheter ablation of AF could be safely completed in these patients.

HbA1c levels as predictors of ablation outcome in type 2 diabetes mellitus and paroxysmal atrial fibrillation.

The aim of this study was to evaluate whether the levels of HbA1c could predict the outcome of ablation in patients with type 2 diabetes mellitus (T2DM) and paroxysmal atrial fibrillation (PAF). The study comprised 149 consecutive patients with T2DM and PAF who underwent their first circumferential pulmonary vein isolation. HbA1c levels were measured before ablation. Cox proportional hazards models were constructed to assess the relationship between HbA1c levels and the recurrence of atrial fibrillation (AF). Of the 149 patients, 60 (40.3 %) developed AF recurrence after a median 12-month follow-up. Multivariate Cox regression analysis revealed that left atrium size and HbA1c were independent predictors of recurrent atrial tachyarrhythmia. Receiver operating characteristic analysis demonstrated that an HbA1c cut-off value of ≥ 6.9 % predicted recurrence with 55.0 % sensitivity and 67.4 % specificity (AUC = 0.634). The success rate of ablation was 69.0 % in patients with an HbA1c value of < 6.9 % compared with 46.8 % in those with an HbA1c value of ≥ 6.9 % (log-rank test, p = 0.004). High levels of HbA1c were associated with an increased risk of recurrence of atrial tachyarrhythmia in patients with T2DM and PAF undergoing catheter ablation.

Additional linear ablation from the superior vena cava to right atrial septum after pulmonary vein isolation improves the clinical outcome in patients with paroxysmal atrial fibrillation: prospective randomized study.

Although circumferential pulmonary vein isolation (CPVI) has been considered as the cornerstone for paroxysmal atrial fibrillation (PAF) ablation, there has been a substantial recurrence rate. We conducted a prospectively randomized study to evaluate whether additional linear ablation from the superior vena cava (SVC) to the right atrial (RA) septum (SVC-L) improves the clinical outcome. This study enroled 200 patients with PAF (male 74.5%, 56.8 ± 11.7 years old) randomly assigned to either the CPVI (n = 100) or CPVI + SVC-L (n = 100) groups. An RA isthmus ablation was performed in all patients. The CPVI + SVC-L group required a longer ablation procedure time (82.7 ± 17.9 min) than the CPVI group (63.6 ± 16.8 min, P < 0.001). The complication rates were 5% in CPVI + SVC-L group and 2% in CPVI group, respectively (P = 0.445). Two CPVI + SVC-L group patients had post-procedural sinus node dysfunction, which recovered within 24 h. During 12.2 ± 5.3 months of follow-up, the recurrence rate was significantly lower in the CPVI + SVC-L group (6%) than the CPVI group (27%, P < 0.001). The post-procedural 3-month follow-up heart rate variability in the CPVI + SVC-L group showed a significantly greater reduction in the rMSSD (25.2 ± 13.7 vs. 13.7 ± 8.5 ms, P < 0.001), HF (10.2 ± 7.1 vs. 5.5 ± 5.8 ms(2), P < 0.001), and LF/HF (1.6 ± 0.5 vs. 0.9 ± 0.3, P < 0.001) than in the CPVI group. In spite of a longer procedure time and risk of transient sinus node dysfunction, an SVC-L in addition to CPVI improved the clinical outcome of catheter ablation, and was associated with post-procedural autonomic neural remodelling in patients with PAF.

Linear ablation in addition to circumferential pulmonary vein isolation (Dallas lesion set) does not improve clinical outcome in patients with paroxysmal atrial fibrillation: a prospective randomized study.

Although the concept of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) was derived from maze surgery, it is unclear if linear ablation in addition to circumferential pulmonary vein isolation (CPVI) reduces the recurrence rate in patients with paroxysmal AF. Therefore, we compared clinical outcomes of CPVI with additional linear ablations (Dallas lesion set) and CPVI in a prospective randomized controlled study among patients with paroxysmal AF. This study enrolled 100 paroxysmal AF patients (male 75.0%, 56.4 ± 11.6 years old) who underwent RFCA and were randomly assigned to the CPVI group (n = 50) or the catheter Dallas lesion group (CPVI, posterior box lesion, and anterior linear ablation, n = 50). The catheter Dallas lesion group required longer procedure (190.3 ± 46.3 vs. 161.1 ± 30.3 min, P < 0.001) and ablation times (5345.4 ± 1676.4 vs. 4027.2 ± 878.0 s, P < 0.001) than the CPVI group. Complete bidirectional conduction block rate was 68.0% in the catheter Dallas lesion group and 100% in the CPVI group. Procedure-related complication rates were not significantly different between the catheter Dallas lesion (0%) and CPVI groups (4%, P = 0.157). During the 16.3 ± 4.0 months of follow-up, the clinical recurrence rates were not significantly different between the two groups (16.0% in the catheter Dallas lesion group vs. 12.0% in the CPVI group, P = 0.564), regardless of complete bidirectional conduction block achievement after linear ablation. Linear ablation in addition to CPVI (catheter Dallas lesion) did not improve clinical outcomes of RFCA in paroxysmal AF patients and required longer procedure times.

Prevalence and clinical outcome of phrenic nerve injury during superior vena cava isolation and circumferential pulmonary vein antrum isolation using radiofrequency energy

Phrenic nerve injury (PNI) is recognized as an important complication during atrial fibrillation ablation. This study aimed to investigate the incidence and outcome of PNI during superior vena cava isolation (SVCI) and circumferential pulmonary vein isolation (CPVI) using radiofrequency (RF) energy and the factors associated with its occurrence. Five hundred sixty-seven consecutive patients who underwent SVCI after CPVI without substrate modification who completed a 12-month follow-up were retrospectively analyzed. Point-by-point RF applications were applied with maximum energy settings of 35 W and 30 seconds for the SVCI. In the former 210 patients, sites where pacing captured the PN were avoided whenever possible; however, the maximum power was 35 W. In the latter 357 patients, RF energy was delivered regardless of PN capture; however, the power at PN capture sites was limited to 10 W during continuous diaphragmatic movement monitoring on fluoroscopy. Circumferential pulmonary vein isolation and SVCI were successfully achieved in all. Twelve patients (2.1%) had PNI during SVCI but not during CPVI. Phrenic nerve injury completely recovered in all patients a median of 8.0 months after the procedure. The prevalence was higher in the former period (3.8% vs 1.1%; P = .03). A multivariate logistic regression analysis revealed that the study period (odds ratio 3.546; 95% CI 1.051-11.965; P = .041) was the sole independent predictor for identifying patients with PNI during SVCI. Phrenic nerve injury occurred in 2.1% of the patients. All occurred during SVCI but not during contemporary CPVI. Energy titration and continuous diaphragmatic movement monitoring significantly decreased the incidence during SVCI.