XaMINA: A Real-World, Prospective, Observational Study of Treatment-Naïve Patients Treated with Rivaroxaban for Stroke Prevention in Atrial Fibrillation in Asia.

INTRODUCTION: The efficacy and safety of rivaroxaban for the prevention of stroke and systemic embolism have been demonstrated in Asian and non-Asian patients with non-valvular atrial fibrillation (NVAF) in multiple studies. However, limited published data exist on its use specifically in treatment-naïve patients from the Asia region. Patients in South Korea and Taiwan can now receive rivaroxaban as first-line therapy, allowing for data generation in this patient group. METHODS: XaMINA was a prospective, real-world, multicenter, single-arm, observational cohort study of patients with NVAF in South Korea and Taiwan naïve to anticoagulation and initiating rivaroxaban. The primary outcome was major bleeding; secondary outcomes included all-cause mortality, symptomatic thromboembolic events, and treatment persistence. RESULTS: In total, 1094 patients were included and the follow-up was 1 year. The baseline mean CHADS2 score was 1.63 ± 0.98, mean CHA2DS2-VASc score was 2.92 ± 1.42, and mean HAS-BLED score was 1.00 ± 0.75. The primary outcome occurred in 20 (1.8%) patients [incidence rate 2.1 events per 100 patient-years (95% CI 1.35-3.25)]. Thromboembolic events occurred in 9 (0.8%) patients, of whom 5 (0.5%) had stroke, 3 (0.3%) myocardial infarction, and 1 (0.1%) a transient ischemic attack. There were no cases of non-central nervous system systemic embolism, and 735 (67.2%) patients persisted with rivaroxaban treatment for 1 year. CONCLUSION: XaMINA demonstrated low incidence rates of major bleeding events and thromboembolic events in patients with NVAF newly initiating rivaroxaban in South Korea and Taiwan, consistent with previous real-world studies reconfirming the results of the ROCKET AF study. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov (identifier NCT03284762) on 15 September 2017.

Long-term evaluation of sensing variability of a floating atrial dipole in a single­lead defibrillator: The mechanistic basis of long-term stability of amplified atrial electrogram.

BACKGROUND: A single­lead implantable cardioverter-defibrillator (ICD) with a floating atrial dipole has been developed to enhance the diagnostic capability of atrial arrhythmias and to facilitate adjudication of arrhythmic events without the additional effort required for atrial lead insertion. However, there have been concerns about the long-term reliability of atrial sensing. METHODS: We enrolled patients with the single-chamber ICD with atrial-sensing electrodes from 4 tertiary university hospitals in Korea. Minimal, maximal, and mean P wave amplitudes were collected at 3-6 months, 6-12 months, and 12-24 months after implantation. The difference between the minimal and maximal sensing amplitudes was calculated as an indicator of the variability of atrial sensing, while the atrial sensing stability was assessed using the mean amplitude. RESULTS: A total of 86 patients were included for analysis. The variability of atrial sensing amplitudes significantly decreased at 12-24 months compared to 3-6 months (p = 0.01), while mean atrial amplitudes were stable throughout the mean follow-up duration of 17.4 months. Nine patients (10.5%) experienced inappropriate ICD therapy mostly due to misclassification of supraventricular tachycardia. CONCLUSIONS: Under the hypothesis that sensing stability can be guaranteed as the variability decreases with time, we suggest that the concern about long-term sensing stability of a floating dipole can be abated with an ICD that has been implanted for over 2 years.

Impact of persistent left superior vena cava on radiofrequency catheter ablation in patients with atrial fibrillation.

AIMS: The impact of persistent left superior vena cava (PLSVC) in atrial fibrillation (AF) patients undergoing radiofrequency catheter ablation (RFCA) is not well known. We performed this analysis to evaluate the electrophysiological characteristics of PLSVC and its role in triggering and maintaining AF. METHODS AND RESULTS: Patients with AF referred to two tertiary hospitals were screened and patients with PLSVC in pre-RFCA imaging studies were enrolled. Among 3967 patients, PLSVC was present in 36 patients (0.9%). There were four morphological types of PLSVC: type 1, atresia of the right superior vena cava (SVC) (n = 2); type 2A, dual SVCs with an anastomosis between right and left SVCs (n = 15); type 2B, dual SVCs without an anastomosis (n = 16); type 3, PLSVC draining into the left atrium (LA; n = 2); and unclassified in one patient. Thirty-two patients underwent RFCA and electrophysiology study focusing on PLSVC: PLSVC was the trigger of AF in 48.4% of patients and the driver of AF in 46.9% of patients. Cumulatively, PLSVC was a trigger or driver of AF in 22 patients (68.8%). Whether to ablate PLSVC was determined by the results of electrophysiology study, and no significant difference in the late recurrence rate was observed between patients who did and did not have either trigger or driver from PLSVC. CONCLUSION: Pre-RFCA cardiac imaging revealed PLSVC in 0.9% of AF patients. This study demonstrated that PLSVC has an important role in initiating and maintaining AF in substantial proportion of patients. Electrophysiology study focusing on PLSVC can help to decide whether to ablate PLSVC.

Comparison between linear and focal ablation of complex fractionated atrial electrograms in patients with non-paroxysmal atrial fibrillation: a prospective randomized trial.

AIMS: Findings regarding efficacy of substrate modification for non-paroxysmal atrial fibrillation (AF) are inconsistent. We prospectively compared clinical outcomes of complex fractionated atrial electrogram (CFAE)-guided focal ablation (CFA) and CFAE-guided linear ablation (CLA) in patients with non-paroxysmal AF. METHODS AND RESULTS: We randomized 150 patients with non-paroxysmal AF into CFA and CLA groups in a 1:1 ratio. Complex fractionated atrial electrogram distribution was evaluated using an automated algorithm of a three-dimensional mapping system. After pulmonary vein isolation (PVI), CFAE-guided ablation was performed in the left atrium and then in the right atrium (RA). When compared with conventional CFA, CLA was performed based on conventional lines, with additional lines. Atrial fibrillation was not induced after PVI alone or with cavotricuspid isthmus ablation in 20.7% of patients. To achieve the endpoint, additional CFAE-guided RA ablation was required in 42.7% and 36.0% of patients undergoing CFA and CLA, respectively (P = 0.403). Atrial fibrillation was terminated during CFAE-guided ablation in 72.9% and 75.0% of patients undergoing CFA and CLA, respectively (P = 0.792). Termination of atrial tachycardia (AT) or non-inducibility of AF/AT was achieved in 61.3% and 68.0% of patients undergoing CFA and CLA, respectively (P = 0.393). The CLA group showed decreased 1-year freedom from AF/AT recurrence (60.0%, CFA vs. 47.3%, CLA; log rank P = 0.085), but no significant difference throughout the follow-up (22.2 ± 21.0 months) (67.1%, CFA vs. 68.9%, CLA; log rank P = 0.298). CONCLUSION: Long-term efficacy of CFAE-guided ablation was unaffected by the ablation technique in patients with non-paroxysmal AF.

Long-Term Clinical Comparison of Procedural End Points After Pulmonary Vein Isolation in Paroxysmal Atrial Fibrillation: Elimination of Nonpulmonary Vein Triggers Versus Noninducibility.

BACKGROUND: Pulmonary vein isolation (PVI) is effective for maintenance of sinus rhythm in 50% to 75% of patients with paroxysmal atrial fibrillation, and it is not uncommon for patients to require additional ablation after PVI. We prospectively evaluated the relative effectiveness of 2 post-PVI ablation strategies in paroxysmal atrial fibrillation. METHODS AND RESULTS: A total of 500 patients (mean age, 55.7±11.0 years; 74.6% male) were randomly assigned to undergo ablation by 2 different strategies after PVI: (1) elimination of non-PV triggers (group A, n=250) or (2) stepwise substrate modification including complex fractionated atrial electrogram or linear ablation until noninducibility of atrial tachyarrhythmia was achieved (group B, n=250). During a median follow-up of 26.0 months, 75 (32.2%) patients experienced at least 1 episode of recurrent atrial tachyarrhythmia after the single procedure in group A compared with 105 (43.8%) patients in group B (P value in log-rank test of Kaplan-Meier analysis: 0.012). Competing risk analysis showed that the cumulative incidence of atrial tachycardia was significantly higher in group B compared with group A (P=0.007). With the exception of total ablation time, there were no significant differences in fluoroscopic time or procedure-related complications between the 2 groups. CONCLUSIONS: Elimination of triggers as an end point of ablation in patients with paroxysmal atrial fibrillation decreased long-term recurrence of atrial tachyarrhythmia compared with a noninducibility approach achieved by additional empirical ablation. The post-PVI trigger test is thus a better end point of ablation for paroxysmal atrial fibrillation.

Relation between left atrial wall composition by late gadolinium enhancement and complex fractionated atrial electrograms in patients with persistent atrial fibrillation: influence of non-fibrotic substrate in the left atrium.

The complex fractioned atrial electrogram (CFAE) has been considered as the catheter ablation target of left atrium (LA) under persistent atrial fibrillation (PeAF). We evaluated the relation between the LA wall composition by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) and the CFAE in patients with PeAF. Forty-three patients underwent LGE-CMR and CFAE mapping before catheter ablation for PeAF. The LA wall substrates were classified into three: the fibrotic, intermediate, and normal substrates by using two thresholds of 2 standard deviation (2-SD) and 6-SD above the mean signal from the normal myocardium. For each of 12 preselected LA wall regions, the composition ratios (CRs) of fibrotic, indeterminate, and normal substrates were calculated as a percentage to the volume of LA wall region, and compared depending on the CFAE, respectively. The CR of normal substrate was significantly greater at the LA wall region with CFAE (52 ± 38% vs. 20 ± 28%, P < 0.01) than without CFAE. In contrast, the LA wall region with CFAE showed significantly lower CRs of intermediate substrate (39 ± 34% vs. 57 ± 31%, P < 0.01) and fibrotic substrate (7 ± 17% vs. 21 ± 24%, P < 0.01) than did the LA wall region without CFAE, respectively. Thus, the high CR (>18%) of normal substrate predicted the CFAE at the corresponding LA wall region with 71% sensitivity and 62% specificity. In conclusion, the evaluation of LA wall normal substrate by LGE-CMR might be useful to predict the CFAE occurrence before catheter ablation of PeAF.

Atrial fibrillation cycle length as a predictor for the extent of substrate ablation.

AIMS: Atrial fibrillation (AF) cycle length (CL) has been demonstrated to be one of the predictors for termination during ablation for AF. We evaluated the AF CL gradient between right atrium (RA) and left atrium (LA) and their mean AF CL in predicting the extent of substrate ablation. METHODS AND RESULTS: One-hundred and thirty-six patients undergoing first ablation for persistent AF were studied. Stepwise ablation, sequentially in the following order: pulmonary veins (PV), LA, and RA, was performed to achieve AF termination. Stepwise ablation terminated AF in 110 patients (81%). In the AF termination group, AF was terminated by PV isolation (PVI) (Group P), PVI plus LA ablation (Group L), and PVI plus LA plus RA ablation (Group R) in 14 patients (13%), 49 patients (44%), and 47 patients (43%), respectively. Group R had much shorter mean AF CL than Group L (156 ± 18 vs. 174 ± 24 ms, P < 0.001) and mean AF CL in Group L was much shorter than Group P (174 ± 24 vs. 209 ± 36 ms, P = 0.004). The RA to LA AF CL gradient was not significantly different between left-side ablation (Group P + Group L) and additional RA ablation (Group R) (P = 0.177). Mean AF CL >180.50 ms predicted AF termination by PVI (Group P) with 79% sensitivity and 84% specificity while mean AF CL >165.25 ms predicted AF termination by left-side ablation (Group P + Group L) with 67% sensitivity and 75% specificity. After a mean follow-up of 15 ± 7 months, freedom from arrhythmia recurrence was significantly higher in left-side ablation (Group P + Group L) than additional RA ablation (Group R) (P = 0.024). CONCLUSION: Baseline mean AF CL may identify the subset of patients in whom persistent AF can be terminated by different extent of substrate ablation, which may in turn predict the chance of recurrence. However, baseline RA to LA AF CL gradient cannot predict the need for additional RA ablation.

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.

AIMS: 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. METHODS AND RESULTS: 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). CONCLUSIONS: 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.

Evaluation of quantification methods for left arial late gadolinium enhancement based on different references in patients with atrial fibrillation.

By using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging, we compared left atrial late gadolinium enhancement (LA-LGE) quantification methods based on different references to characterize the left atrial wall in patients with atrial fibrillation (AF). Thirty-eight patients who underwent three-dimensional LGE-CMR imaging before catheter ablation for AF were classified into three groups depending on their clinical AF type: (1) paroxysmal AF (PAF; n = 12); (2) persistent AF (PeAF; n = 16); and (3) recurrent AF after catheter ablation (RAF; n = 10). To quantify LA-LGE on LGE-CMR imaging, we used the thresholds of 2 standard deviations (2-SD), 3-SD, 4-SD, 5-SD, or 6-SD above the mean signal from the unenhanced left ventricular myocardium, and we used the full width at half maximum (FWHM) technique, which was based on the maximum signal from the mitral valve with high signal intensity. The 6-SD threshold and FWHM techniques were statistically reproducible with an intraclass correlation coefficient >0.7. On applying the FWHM technique, the normalized LA-LGE volume by LA wall area showed a significant difference between the RAF, PeAF, and PAF groups (0.22 ± 0.04, 0.16 ± 0.06, and 0.09 ± 0.03 mL/cm(2), respectively) (P < 0.05). Furthermore, most of the fibrotic scarring and low-voltage tissue on the electroanatomic map corresponded well with the extent of LA-LGE. The FWHM technique based on the mitral valve can provide a reproducible quantification of LA-LGE related to AF in the thin LA wall.

Paced QRS axis as a predictor of pacing-induced left ventricular dysfunction.

PURPOSE: The selection of the optimal right ventricular (RV) pacing site remains unclear. We hypothesized that a normal paced QRS axis would provide a physiological ventricular activation and lead to a better long-term outcome. METHODS: We evaluated 187 patients who underwent a permanent pacemaker implantation and were dependent on RV pacing. The pacing sites were classified as the apex and non-apex according to the chest radiography. A paced QRS axis was defined as that between -30° and 90°. Preservation of the left ventricular (LV) systolic function was defined as that with a <10 % decrease in the ejection fraction after the pacemaker implantation. RESULTS: The median follow-up period was 5.8 years (interquartile 3.9-9.0). Radiographically, the RV leads were located in the apex (n = 148, 79 %) or non-apex (n = 39, 21 %). In the electrocardiogram, normal paced and abnormal paced QRS axes were observed in 28 patients (15 %) and 159 patients (85 %), respectively. The LV ejection fraction was decreased in the patients with an abnormal paced QRS axis (-10 ± 10 %, P < 0.001), but not in those with a normal axis (0 ± 6 %, P = 0.80). The electrocardiographic determinant differentiated a preserved LV function (95 % vs. 35 %, log-rank P = 0.04). Among the patients with radiographically non-apical pacing, a normal paced QRS axis was an additional meaningful predictor of a preserved LV function after the pacemaker implantation (95 % vs. 24 %, log-rank P = 0.002). CONCLUSION: Compared with the radiographic method, a normal paced QRS axis was associated with a preserved LV function.

Relationship between complex fractionated atrial electrograms during atrial fibrillation and the critical site of atrial tachycardia that develops after catheter ablation for atrial fibrillation.

INTRODUCTION: Complex fractionated atrial electrograms (CFAEs) are a substrate modification target in patients with atrial fibrillation (AF). However, whether CFAEs can be also arrhythmogenic grounds of atrial tachycardia (AT) presenting after AF ablation remains to be determined. We investigated the relationship between CFAEs and the critical site of AT after CFAE-guided AF ablation. METHODS AND RESULTS: Seventy-two patients showing AT after pulmonary vein isolation and further CFAE-guided ablation were included. The termination sites of the 95 distinct ATs were annotated on color-coded CFAE cycle maps. Of the 95 ATs, 61 (64.2%) had a termination site at the border zone of CFAE or in a highly dense CFAE area. The cycle length (CL) of the ATs terminated in the CFAE area was significantly shorter than the CL of those terminated in the non-CFAE area. The cut-off CL for ATs terminated at the CFAE area was 270 milliseconds, with sensitivity/specificity of 70%/75%. In 67.2% of the ATs terminating at the CFAE-related area, the major termination sites were the anterior wall near the LA appendage, septum and roof, whereas the peri-mitral isthmus was the most common termination site of ATs in the non-CFAE area. CONCLUSIONS: The areas showing CFAE and their border zones were frequently associated with termination of ATs presenting after AF ablation. The mean CL of ATs originating near CFAEs was significantly shorter than that of those terminated in non-CFAE areas. The targeted CFAE areas also provided the arrhythmogenic milieu for AT developing after AF ablation.

The spatial distribution of atrial fibrillation termination sites in the right atrium during complex fractionated atrial electrograms-guided ablation in patients with persistent atrial fibrillation.

BACKGROUND: The role of right atrial (RA) ablation guided by complex fractionated atrial electrograms (CFAE) in atrial fibrillation (AF) has been debated. This study evaluated the spatial distribution of RA CFAE, the critical sites, and the predictors of successful termination of longstanding persistent AF during RA ablation. METHODS: A total of 97 patients with persistent AF who received automated detection of CFAE mapping and ablation at the RA for sustained AF after pulmonary vein isolation and left atrial (LA) CFAE-guided ablation were analyzed. The AF termination patterns and CFAE areas were analyzed. RESULTS: Forty-eight (49%) patients successfully converted to atrial tachycardia (AT) or sinus rhythm (SR) during CFAE-guided ablation at the RA. Of these, 7 (15%) patients converted directly to SR, and 41 (85%) converted via AT. The crista terminalis (CT) was the most common site for AT conversion during RA CFAE ablation, followed by the RA appendage and RA septum. Patients with larger RA volumes (> 145 mm3) had lower rates of SR or AT conversion during RA CFAE ablation. Patients with AF termination during RA CFAE ablation had less late recurrence than those without AF termination (P = 0.003). CONCLUSION: A half of patients with persistent AF refractory to LA ablation successfully converted to AT or SR during automated CFAE-guided ablation at the RA. The most common critical sites for AF termination were the CT and RA appendage and septum. Patients with AF termination during procedure whether LA CFAE only or after RA CFAE ablation had better outcome with less late recurrence of atrial tachyarrhythmia compared to those without AF termination.

Clinical significance of induced atrial tachycardia after termination of longstanding persistent atrial fibrillation using a stepwise approach.

INTRODUCTION: The utility of inducibility test of atrial tachycardia (AT) in patients with longstanding persistent atrial fibrillation (AF; LPAF) is unclear. This study aimed to evaluate the significance of induced AT and the impact of their ablation on the clinical outcome. METHODS: In 194 patients with LPAF (>1 year) who underwent catheter ablation (pulmonary vein isolation with substrate ablation), an inducibility test was performed after AF termination. RESULTS: AT was induced in 108 (56%) patients (induced AT group); neither AT nor AF was inducible in 37 (19%, noninduction group). During 39 ± 21 months, AT recurred in 30 patients (28%), AF in 19 (17%), and no arrhythmia in 56 (52%) among induced AT group, although there was a recurrence of AT in 9 (24%, P = 0.68), AF in 6 (16%, P = 0.85), and no arrhythmia in 22 (60%, P = 0.42) among noninduction group (P = NS). Note that 10 patients with repeated ablation in induced AT group revealed 8 different and 2 similar recurrent ATs compared to the induced ATs at first session. The mean cycle length of induced AT that terminated by ablation (271 ± 64 ms) was longer than that without (249 ± 58 ms, P < 0.05). In induced AT group, AT recurrence rate in patients who achieved AT termination by ablation was lower than those without termination (5% vs 36%, P < 0.05). CONCLUSIONS: ATs that are inducible after LPAF termination do not necessarily become clinical AT. However, patients who achieved noninducibility of AT by ablating slower cycle length of AT had better outcomes.

Circadian and seasonal variations of ventricular tachyarrhythmias in patients with early repolarization syndrome and Brugada syndrome: analysis of patients with implantable cardioverter defibrillator.

INTRODUCTION: The circadian and seasonal patterns of ventricular tachyarrhythmia (VTA) in patients with early repolarization syndrome (ERS) have not been determined. We compared the timing of VTAs in patients with ERS and Brugada syndrome (BS). METHODS AND RESULTS: We enrolled patients with ERS (n = 14) and BS (n = 53) who underwent implantable cardioverter defibrillator (ICD) implantation. The timing of VTAs, including cardiac arrest and appropriate shocks, was determined. During follow up of 6.4 ± 3.6 years in the ERS group and 5.0 ± 3.3 years in the BS group, 5 of 14 (36%) ERS and 10 of 53 (19%) BS patients experienced appropriate shocks (P = 0.37). Cardiac arrest showed a trend of nocturnal distribution peaking from midnight to early morning (P = 0.14 in ERS, P = 0.16 in BS). Circadian distribution of appropriate shocks showed a significant nocturnal peak in patients with ERS (P < 0.0001) but a trend toward a nocturnal peak in patients with BS (P = 0.08). There were no seasonal differences in cardiac arrest in patients with ERS and BS. However, patients with ERS showed a seasonal peak in appropriate shocks from spring to summer (P < 0.0001). There was no significant seasonal peak in patients with BS. The timing of VTAs (cardiac arrest plus appropriate shock) showed significant nocturnal distributions in patients with ERS and BS (P < 0.01, respectively). A significant clustering of VTAs was noted from spring to summer (P < 0.01) in patients with ERS, but not in patients with BS (P = 0.42). CONCLUSIONS: Incidence of VTAs showed marked circadian variations with night-time peaks in patients with ERS and BS.

Characteristics of complex fractionated atrial electrogram in the electroanatomically remodeled left atrium of patients with atrial fibrillation.

BACKGROUND: Complex fractionated atrial electrogram (CFAE) guided ablation is effective in some patients with persistent atrial fibrillation (PeAF), but the pattern of CFAE may be different in the remodeled left atrium (LA). METHODS AND RESULTS: In 100 AF patients (83 males, 55.0+/-10.6 years old) with AF (51 paroxysmal AF (PAF), 49 PeAF) who underwent catheter ablation, CFAE cycle length (CL) and distribution (NavX 3D map) were compared according to the LA volume (3D-CT) and endocardial voltage (during high right atrial pacing 500-ms (Vol(PACE)) and AF (Vol(AF); NavX). The mean CFAE-CL was longer (P=0.003) and the % area CFAE was smaller (P=0.006) in patients with LA >or=125 ml than those with <125 ml. The mean CFAE-CL was longer in patients with Vol(PACE) <1.7 mV than those with >or=1.7 mV (P=0.002) and in Vol(AF) <0.7 mV than >or=0.7 mV (P<0.001). The % area CFAE was smaller in patients with Vol(PACE) <1.7 mV than those with >or=1.7 mV (P=0.006). The incidence of septal CFAE was consistently high, regardless of the degree of LA remodeling. CONCLUSIONS: In the AF patients with an electroanatomically remodeled LA, the % area of CFAE was smaller and mean CFAE-CL was longer than in those with a less remodeled LA. However, the majority of CFAE are consistently positioned on the septum in the remodeled LA.

Role of residual potentials inside circumferential pulmonary veins ablation lines in the recurrence of paroxysmal atrial fibrillation.

BACKGROUND: Residual gaps due to incomplete ablation lines are known to be the most common cause of recurrent atrial fibrillation (AF) after catheter ablation. We hypothesized that any residual potentials at the junction of the left atrium and pulmonary vein (PV), inside the circumferential PV ablation (CPVA) lines, would contribute to the recurrence of AF or post-AF ablation atrial flutter (AFL); therefore, the elimination of these potentials increases AF-/AFL-free survival rates. METHODS AND RESULTS: One hundred and two patients with paroxysmal AF (PAF) were enrolled and prospectively randomized to a group with ablation of residual potentials as add-on therapy to CPVA + PV electrical isolation (PVI) (group 1, n = 49), or a group without ablation of the residual potentials (group 2, n = 53). Post-CPVA residual potentials, inside the ablation lines, were identified by contact bipolar electrode mapping catheter and a detailed 3-dimensional voltage map. Twenty-three patients in group 1 and 18 patients in group 2 had post-CPVA residual potentials (46.9% vs 34.0%, P = 0.182). The AF-/AFL-free survival rate during follow-up of 23.3 ± 7.9 months was not different in comparisons between the 2 groups (P = 0.818), and 79.6% and 81.1% of the patients in groups 1 and 2 maintained a sinus rhythm (P = 0.845), respectively. CONCLUSIONS: Residual potentials inside CPVA were commonly found in the patients with PAF after CPVA + PVI. Further ablation of residual potentials did not increase the efficacy of catheter ablation in patients with PAF.