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BACKGROUND The impact of contact force (CF) monitoring in pulmonary vein (PV) isolation after a circumferential anatomic ablation (CAA) is unknown. We analyze the usefulness of CF monitoring in acute PV isolation and procedure parameters using a CAA. METHODS Fifty patients with paroxysmal atrial fibrillation were randomized into CF-on (CF >10 grams; n = 25) or CF-off (CF blinded; n = 25) groups. We performed a first round of CAA with a ThermoCool(®) SmartTouch(®) catheter blinded to the LASSO(®) catheter (Biosense Webster, Diamond Bar, CA, USA), with radiofrequency (RF) lesions tagged with the VisiTag(™) Module. After the CAA, each PV was reviewed with the LASSO(®) catheter recording the segments with gaps. RESULTS All the PVs were isolated with a CAA in 20 patients of the CF-on versus eight of the CF-off (P = 0.001). Of the 45 segments with gaps in the left PVs, 38 were from the CF-off (P = 0.0001). Of the eight segments with gaps in the right PVs, seven were from the CF-off (P = 0.06). The CF in the left PVs was higher in the CF-on (16.3 ± 3.2 grams vs 10.5 ± 4.3 grams; P = 0.0001) and similar in the right PVs (17.6 ± 3.6 grams vs 15.2 ± 5.3 grams; P = 0.08). All of the gaps were closed with additional RF LASSO(®) -guided touch-up. Procedure and fluoroscopy times were shorter in the CF-on (139 ± 24 minutes vs 157 ± 32 minutes and 20 ± 6 minutes vs 24 ± 7 minutes; both P = 0.039). At 12 months the patients free of AF recurrence was 84% CF-on versus 75% CF-off (log-rank P = 0.4) [corrected]. CONCLUSIONS In paroxysmal atrial fibrillation, a CAA guided by CF reduces PV gaps and shortens the procedure parameters at the expense of the left PVs.

Background Pulmonary vein isolation (PVI) causes a reduction in left atrium size that is attributable to reverse atrial remodeling (RAR). The objective of this study was to identify predictors of RAR and determine its association with other parameters of improvement in cardiac function. Methods It is a prospective study with 74 patients (52 ± 9 years old, 81% male), and 51% of patients had paroxysmal atrial fibrillation. Patients were serially assessed with transthoracic echocardiography; plasma N-terminal B-type natriuretic peptide (NT-proBNP); and high-sensitivity C-reactive protein levels at baseline and 3, 6, and 12 months following the PVI. RAR was defined as a reduction in the left atrial volume index (LAV-index) >10% from baseline at the end of follow-up. A multivariate analysis was conducted to identify predictors of RAR. Results The LAV-index decreased significantly during follow-up in the entire population (P = 0.0005). RAR (experienced by 63.5% of the patients) was more frequent (76% vs. 42%; P = 0.004) and pronounced (reduction 16.65 ± 14% vs. 8 ± 14%; P = 0.015) in patients with a successful ablation (46 of 74 patients, 62.2%). Only patients with RAR showed significant improvement in NT-proBNP levels (P = 0.0001), systolic function (P = 0.035), and diastolic function (P = 0.005). Multivariable analysis revealed that a successful ablation (odds ratio [OR] = 4.6; 95% confidence interval [CI] 1.46–14.68; P = 0.009), LAV-index (OR = 1.15; 95% CI 1.03–1.2; P = 0.021), and patient's body mass index (OR = 0.84; 95% CI 0.74–0.96; P = 0.012) were independent predictors of RAR. Conclusions Successful PVI ablation is the main predictor of RAR that is associated with other parameters of improvement in cardiac function. The patient's body mass index may have a negative effect on RAR.

Preablation Atrial Fibrillation Burden Aims Data on the success rate of ablation in atrial fibrillation (AF) are controversial. Our hypothesis is that the efficacy must be evaluated considering the AF burden (AFB) before the procedure. Moreover, the clinical significance of early recurrence (ERAT) of AF or atrial tachyarrhythmias (AT) is debatable. The aim is to describe the outcome of pulmonary vein isolation in paroxysmal AF through a subcutaneous cardiac monitor (ICM) implanted before the procedure. Methods Using CARTO 3, circumferential lesions around the pulmonary veins were placed. The study endpoint was the first documented recurrence of AF/AT by ICM after the blanking period (3 months). AFB (percentage of time in AF/AT) was collected every month before and after the procedure during the 12-month follow-up. Results The ICM was implanted 94 ± 23 days before the procedure in 35 patients with paroxysmal AF (54 ± 11 years, refractory to 1.8 ± 0.6 antiarrhythmic drugs). Cumulative AFB before the procedure and after the blanking period was 2.5% (1–5%) versus 0% (0–0.25%), P < 0.001. Twenty patients (57.1%) were free of documented AF/AT recurrence, 5 patients (14.2%) reduced the AFB 90%, 6 patients (17.1%) continued the same, and 4 patients (11.4%) increased the AFB 90% for AT. The success rate with second procedure was 71.4%. All 13 patients with ERAT had recurrence after the blanking period. Conclusions The outcome of pulmonary vein isolation in patients with paroxysmal AF is well documented by an ICM. The success rate is dependent of the previous AFB that can be randomly variable and lower than expected. ERATs predict late recurrence.

We describe a case of ablation of atrioventricular nodal reentrant tachycardia in a patient with tricuspid atresia and L-malposition of great vessels using an electroanatomical mapping system integrated with cardiac magnetic resonance imaging. Atrial activation mapping during tachycardia identified the retrograde fast pathway proximal to the His bundle, observed in the left interatrial septum. Ablation was successfully completed below this area. Map integration with the patient's anatomy allowed a safe, individualized procedure. (PACE 2012; 35:e293–e295)