003). Administering BTPs was an independent factor that protected against ERAAs (odds ratio 0.181, [95% confidence interval 0.059-0.559], 
  =.003).
 
  BTPs may prevent ERAAs after ablation.
 BTPs may prevent ERAAs after ablation.
  Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is associated with left atrial (LA) remodeling; however, its association with right atrial (RA) remodeling remains unclear.
 
  This study aimed to identify whether RA structural remodeling could predict recurrence of AF after PVI.
 
  This study prospectively analyzed 245 patients with AF who had undergone PVI. RA and LA volumes were determined by contrast-enhanced computed tomography. Atrial structural remodeling was defined as an atrial volume of ≥110mL according to previous reports and receiver operating characteristic curve analysis.
 
  After excluding 32 patients, 213 patients were analyzed. During a follow-up period of 12months, 41 patients (19%) demonstrated atrial arrhythmia recurrence after PVI. With the Cox proportional-hazards model, RA structural remodeling was the only predictor of arrhythmia recurrence (hazard ratio, 1.012; 95% confidence interval 1.003-1.021; 
  =.009). Kaplan-Meier analysis showed that arrhythmia recurrence was more frequent in the RA structural remodeling group compared with the group without RA remodeling (log-rank, 
  <.001), and the arrhythmia-free survival rates in these groups at 12months were 68.0% and 91.4%, respectively. Additionally, there was a significant difference in recurrence-free survival after RA structural remodeling in each type of AF (log-rank, 
  <.001).
 
  RA structural remodeling is a useful predictor of clinical outcome after PVI regardless of the type of AF. Our results suggest that patients without RA structural remodeling may be good candidates for successful ablation with PVI.
 RA structural remodeling is a useful predictor of clinical outcome after PVI regardless of the type of AF.  https://www.selleckchem.com/products/MG132.html  Our results suggest that patients without RA structural remodeling may be good candidates for successful ablation with PVI.
  After mitral isthmus (ΜΙ) catheter ablation, perimitral atrial flutter (PMF) circuits can be maintained due to the preservation of residual myocardial connections, even if conventional pacing criteria for complete MI block are apparently met (MI pseudo-block). We aimed to study the incidence, the electrophysiological characteristics, and the long-term outcome of these patients.
 
  Seventy-two consecutive patients (mean age 62.4±10.2, 62.5% male) underwent MI ablation, either as part of an atrial fibrillation (AF) ablation strategy (n=35), or to treat clinical reentrant atrial tachycardia (AT) (n=32), or to treat AT that occurred during ablation for AF (n=5). Ιn all patients, the electrophysiological characteristics of PMF circuits were studied by high-density mapping.
 
  Mitral isthmus block was successfully achieved in 69/72 patients (95.6%). Five patients developed PMF after confirming MI block. In these patients, high-density mapping during the PMF showed a breakthrough in MI with extremely low impulse coneded to exclude residual conduction.
  Although usefulness of VISITAG SURPOINT (VS) on pulmonary vein isolation (PVI) in catheter ablation of atrial fibrillation has been reported, optimal VS thresholds can depend on the inter-tag distance (ITD) and vice versa. We validated the efficacy of PVI with lower target ITDs and VS values than in previous studies.
 
  Retrospective review of consecutive patients (N=100) with paroxysmal (n=32) or persistent AF (n=68) undergoing VS-guided ablation between 09/2018 and 08/2019 was conducted. All procedures were performed by two operators. Target VS values were 425 (anterior), 375 (posterior), and 325 (near the esophagus). Target ITD was 4mm.
 
  Acute PVI was achieved in all cases, however, 13 residual gaps in 12 patients were observed after initial encirclement (first pass isolation 88%). Ten gaps due to spontaneous PV reconnections (PVR) were found in nine patients (9%). These 23 gaps had similar median VS (gap-related vs non-gap 429 vs 410, 
  =.4545) and power (36 vs 36W, 
  =.4843), higher contact force (13.8 vs 11.0g, 
  =.0061), and larger ITD (5.3 vs 3.7mm, 
  <.001) when compared to the remaining tags. Only ITDs were independently associated with gap formation in multivariate analysis. One-year Kaplan-Meier freedom from any atrial arrhythmia was 87.2%. Eight patients received repeat ablation (8.1%) and of these, 6 (75%) were free from PVR.
 
  Favorable rates of first pass isolation, acute PVR, and long-term procedure success were achieved using lower VS values than in previous reports. With a target VS value of 375-425, ITDs of 4mm was sufficient for durable PVI.
 Favorable rates of first pass isolation, acute PVR, and long-term procedure success were achieved using lower VS values than in previous reports. With a target VS value of 375-425, ITDs of 4 mm was sufficient for durable PVI.
  A novel measurement of the local impedance (LI) and electrograms recorded from micro-electrodes on catheter tip has been developed. However, the data during pulmonary vein (PV) ablation is not sufficient. We aimed to investigate the utility of this measurement during initial atrial fibrillation (AF) ablation.
 
  We investigated 111 representative radiofrequency applications in 7 AF patients without a history of prior ablation (6 males, age 68 [65-72] years, 2 persistent AF). The ablation strategy was PV isolation for paroxysmal AF and single ring box isolation for persistent AF, using MiFi catheter. The correlation of the generator impedance (GI) drop and LI drop after radiofrequency applications and the predictive value of the initial LI elevation before radiofrequency applications for LI drop were analyzed. Also, the LI and GI drop were investigated according to the location of RF applications.
 
  The LI drop was higher than GI drop (23.7 [16.4-35.7] and 9.0 [6.0-12.0]; 
  <.01). There were correlations between the initial LI elevation and LI drop (
  
  =0.466, 
  <.01) and between the LI and GI drop (
  
  =0.263, 
  <.01). The LI drops significantly differed according to the different anatomical localizations by the Kruskal-Wallis test, although the GI drops did not differ (
  <.01 and 
  =.49, respectively).
 
  LI drop was associated with initial LI elevation and was larger than GI drop. LI drop was different according to locations, although GI drop was not. These findings might indicate that LI drop would be a more sensitive marker for lesion formation than GI drop.
 LI drop was associated with initial LI elevation and was larger than GI drop. LI drop was different according to locations, although GI drop was not. These findings might indicate that LI drop would be a more sensitive marker for lesion formation than GI drop.