Stepwise endo-/epicardial catheter ablation for atrial fibrillation: The Mediterranea approach.

BACKGROUND: Outcomes of catheter ablation (CA) among patients with nonparoxysmal atrial fibrillation (AF) are largely disappointing. OBJECTIVE: We sought to evaluate the feasibility, effectiveness, and safety of a single-stage stepwise endo-/epicardial approach in patients with persistent/longstanding-persistent AF. METHODS: We enrolled 25 consecutive patients with symptomatic persistent (n = 4) or longstanding-persistent (n = 21) AF and at least one prior endocardial procedure, who underwent CA using an endo-/epicardial approach. Our anatomical stepwise protocol included multiple endocardial as well as epicardial (Bachmann's bundle [BB] and ligament of Marshall ablations) components, and entailed ablation of atrial tachycardias emerging during the procedure. The primary outcome was freedom from any AF/atrial tachycardia episode after a 3-month blanking period. The secondary outcome was patients' symptom status during follow-up. RESULTS: The stepwise endo-/epicardial approach allowed sinus rhythm restoration in 72% of patients, either directly (n = 6, 24%) or after AF organization into atrial tachycardia (n = 12, 48%). BB's ablation was commonly implicated in arrhythmia termination. After a median follow-up of 266 days (interquartile range, 96 days), survival free from AF/atrial tachycardia was 88%. Antiarrhythmic drugs could be discontinued in 22 patients (88%). As compared to baseline, more patients were asymptomatic at 9-month follow-up (0% vs. 56%, p = .02). Five patients (20%) developed mild medical complications, whereas one subject (4%) had severe kidney injury requiring dialysis. CONCLUSION: A single-stage endo-/epicardial CA resulted in favorable rhythm and symptom outcomes in a cohort of patients with symptomatic persistent/longstanding-persistent AF and one or more prior endocardial procedures. Epicardial ablation of BB was commonly implicated in procedural success.

A modified surgical ablation line for atrial fibrillation. The Bachmann line.

Surgical treatment of atrial fibrillation generally consists in the isolation of the pulmonary veins ("box-lesion"). Bachmann's bundle is a cardiac structure that may play an important role in the genesis of the atrial fibrillation. Surgical isolation of such bundle has not been reported before. We aim to describe how to perform minimally invasive epicardial pulmonary vein isolation along with the isolation of the Bachmann's bundle. Adding the surgical ablation line of Bachmann's bundle is a feasible, fast, and easy procedure that may be contribute to the reduction of atrial fibrillation relapses.

Continuous spikes and waves during slow sleep in a child with karyotype 47, XYY.

The XYY syndrome is a sex chromosome aneuploidy occurring in one of 1,000 live male births. Only few data exist regarding the correlation between this syndrome and epilepsy. An EEG pattern suggestive of benign focal epilepsy with centro-temporal spikes has recently been described in four XYY patients. We report the first patient with XYY trisomy, rolandic spikes, and atypical evolution with continuous spikes and waves during slow sleep (CSWSS). The present report suggests that the association between an EEG pattern similar to that of BECTS and 47, XYY karyotype may not be coincidental. Moreover, we show that an atypical evolution with CSWSS may occur in this chromosomal disorder.

Incidence and significance of early recurrences associated with different ablation strategies for AF: a STAR-AF substudy.

BACKGROUND: Early recurrences of atrial tachyarrhythmias (ERAT) are common after atrial fibrillation (AF) ablation, and predict late recurrences (LR). We sought to determine the impact of different ablation strategies on ERAT and LR. METHODS AND RESULTS: The STAR-AF trial randomized 100 patients with paroxysmal or persistent AF to ablation of complex fractionated electrograms (CFAE) alone, pulmonary vein isolation (PVI) alone, or combined PVI + CFAE. Patients were followed for 12 months. ERAT was defined as any recurrence of AF, atrial tachycardia, or flutter (AT/AFL) >30 seconds during the first 3 months of follow-up. LR was defined as any recurrence of AF/AT/AFL >30 seconds 3-12 months post. Forty-nine patients experienced ERAT. The index ablation strategy was the only independent predictor of ERAT on multivariate analysis (HR 2.24 PVI vs PVI + CFAE; and HR 2.65 CFAE vs PVI + CFAE). Fifty-two patients experienced LR. The presence of ERAT (HR 3.23), the use of antiarrhythmic drug (AAD) in the first 3 months postablation (HR 2.85), and the index ablation strategy were independently associated with LR (HR 3.42 PVI vs PVI + CFAE; HR 4.72 CFAE vs PVI + CFAE). Thirty-five of 49 (71%) patients with ERAT and 17 (33%) of 51 patients without ERAT had LR (P < 0.0001). Among patients with ERAT, increased left atrium size (HR 1.08), the use of AAD in the first 3 months postablation (HR 2.86) and the index ablation strategy were independently associated with LR (HR 4.77 PVI vs PVI + CFAE; HR 4.45 CFAE vs PVI + CFAE). CONCLUSION: ERAT is common following AF ablation and is strongly associated with LR. Although CFAE ablation alone results in higher rates of early and LR, the addition of CFAE to PVI results in increased long-term success without an increase in ERAT.

The awareness and acceptance of anti-COVID 19 vaccination in adolescence.

BACKGROUND: COVID-19 had devastating effects on children's and adolescents' life, including neuropsychological impairment, discontinuation of social life and education. Since June 2021, antiCOVID19 vaccination has become available to adolescents in Italy up to 12 years and since December 2021 to children aged more than 5 years. The pediatric population represents a challenging target for vaccination. Aim of the study is to perform a survey among adolescents to explore factors associated with COVID 19 immunization and their perceptions about COVID-19 vaccines. METHODS: Italian students aged 10-17 years were invited to participate in an anonymous online survey regarding their immunization against COVID-19 and their opinion on the immunization practice through a web link to the questionnaire. The study period was March-June 2022. Statistical analysis was performed with SPSS v 21. RESULTS: In the study period, 895 students entered the survey. A total of 87.3% of respondents were immunized against SARS-CoV2. The most important predictors of being immunized against SARS-CoV2 were having both parents immunized (p < 0, 001) and being aged over 12 years. In the unvaccinated group, the decision was mostly influenced by the family (65.8%). Regardless the immunization status, respondents were willing to receive information about COVID 19 vaccination mostly by their family doctor (51.8%) and at school (28.9%). CONCLUSIONS: Parents' decisions and attitudes strongly affected the immunization status of adolescents. Students' willing to receive COVID 19 vaccine information by family doctors and at school, underline the potential role of paediatricians and school educators in contributing to an increased vaccine coverage among the paediatric age.

Targeting Bachmann's bundle in hybrid ablation for long-standing persistent atrial fibrillation: a proof of concept study.

BACKGROUND: Catheter-based or surgical procedures in patients with long-standing persistent atrial fibrillation (LSPAF) remain a challenge. As a result, different approaches including hybrid (surgical and endocardial) ablation have been developed. Bachmann's bundle (BB) is a mainly epicardial structure capable of sustaining arrhythmic reentry that could be involved in the development and perpetuation of atrial fibrillation. We investigated the efficacy and safety of an adjunctive BB ablation in LSPAF patients undergoing hybrid ablation. METHODS: In a two-arm non-randomized study, consecutive LSPAF patients undergoing epicardial isolation of pulmonary veins with left atrial posterior wall (box lesion) with (n = 30, BB group) and without additional BB ablation (n = 30, CONV group) were enrolled in the study. All patients underwent an endocardial procedure within 6 weeks post-surgery to assess for potential lesion gaps and additional atrial substrate modification. The primary endpoint was freedom from AF through 12 months of follow-up. RESULTS: The two-staged hybrid ablation was successfully completed in all patients. One-year freedom from atrial arrhythmias recurrence rates was 96.6% in the BB group vs 76.6% in the CONV group (p = 0.025). At procedure completion, 30 (100%) and 17 (56%) patients had a spontaneous cardioversion in BB and CONV group, respectively (p < 0.001). No significant differences in quality of life or complication rates were observed. CONCLUSIONS: This initial experience shows, for the first time, that adjunctive BB ablation in the setting of hybrid ablation for LSPAF is a feasible and effective approach in increasing maintenance of sinus rhythm without increasing complication rates.

Two-Dimensional Transesophageal Echocardiography Assessment of the Major Aortic Annulus Diameter in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Multidetector computed tomography (MDCT) is the gold standard in annulus sizing before transcatheter aortic valve replacement (TAVR). However, MDCT has limited applicability in specific subgroups of patients, such as those with atrial fibrillation and chronic kidney disease. Two-dimensional transesophageal echocardiography (2DTEE) has traditionally been limited to the long-axis measurement of the anteroposterior diameter of the aortic annulus. We describe a new 2DTEE approach for the measurement of the major diameter of the aortic annulus. METHODS: Seventy-six patients with symptomatic severe aortic valve stenosis and high surgical risk underwent MDCT and 2DTEE before TAVR. A modified five-chamber view was used to measure the major aortic annulus diameter. This was obtained starting from a mid-esophageal four chamber and retracting the TEE probe up until the left ventricular outflow tract and the left and noncoronary aortic cusps were visualized: major aortic annulus diameter was measured as the distance between their insertion points in systole. RESULTS: Major aortic annulus diameters measured at 2DTEE showed good correlation with MDCT diameter (r = 0.79; P < 0.001) and perimeter (r = 0.87; P < 0.0001). Using factsheet-derived sizing criteria, 2DTEE alone would have allowed accurate sizing in 75% of patients, with 21% of oversizing predominantly with smaller annuli. CONCLUSIONS: We describe a new method for 2DTEE measurement of the major aortic annulus diameter; this approach is simple, correlates with MDCT, and allows adequate TAVR sizing in most patients. These findings may help in the assessment of patients with contraindications to or inadequate MDCT images.

Catheter, surgical, or hybrid procedure: what future for atrial fibrillation ablation?

BACKGROUND: The debate on the best treatment strategy for atrial fibrillation (AF) has expanded following the introduction of the so-called "hybrid procedure" that combines minimally invasive epicardial ablation with endocardial catheter ablation. However, the advantage of the hybrid approach over conventional epicardial ablation remains to be established. METHODS: From June 2008 to December 2020, 609 surgical AF ablation procedures through a right minithoracotomy were performed at our institution. From 2008 to 2011, a unipolar radiofrequency (RF) device was used, whereas from 2011 to 2020 a bipolar RF device was used. In addition, between September 2016 and April 2017, 60 patients underwent endocardial completion of epicardial linear ablation. In 30 of these latter patients, surgical isolation of the Bachmann's bundle (BB) was also performed. Starting from 2021, surviving patients at follow-up were asked to undergo electrocardiographic evaluation and left ventricular function assessment and to complete a questionnaire addressing quality of life and predisposing factors for recurrent AF. RESULTS: The ablation procedure was completed in all patients. Upon discharge, 30 (4.9%) patients showed recurrence of AF, whereas the remaining patients (95.1%) were in sinus rhythm. All patients in whom a hybrid approach was used either with or without BB ablation were discharged in sinus rhythm. After a mean follow-up of 74 months, 122 (20%) patients developed recurrent AF, including 19.9% in whom a unipolar RF device was used, 21% in whom a bipolar RF device was used, 23% who had undergone a hybrid procedure without BB ablation and 3.3% who had undergone a hybrid procedure with BB ablation. On multivariate analysis, reduced left ventricular ejection fraction, worsening of European Heart Rhythm Association symptom class, and cognitive impairment or depression during follow-up were found to be significantly associated with AF recurrence. CONCLUSIONS: Surgical AF ablation through a right minithoracotomy is safe and may allow the creation of additional linear lesions, particularly in the BB. The placement of adjunctive linear lesions in the setting of a hybrid procedure can be more effective in reducing the risk for AF recurrence than isolated surgical ablation or hybrid ablation without the addition of further linear lesions, with no incremental risk to the patient.

Stand-Alone Thoracoscopic Left Atrial Appendage Closure in Nonvalvular Atrial Fibrillation Patients at High Bleeding Risk.

OBJECTIVE: In nonvalvular atrial fibrillation (AF) patients at high bleeding risk, oral anticoagulants (OAC) may be contraindicated, and percutaneous left atrial appendage (LAA) closure has been advocated. However, following percutaneous procedure, either OAC or dual antiplatelet treatment is required. In this study, we present our experience in treating nonvalvular AF patients at high bleeding risk with thoracoscopic LAA closure with no subsequent antithrombotic therapy. METHODS: From April 2019 to January 2020, 20 consecutive AF patients, mean age 75.1 years, 16 (80%) males, underwent thoracoscopic LAA closure as a stand-alone procedure, using an epicardial clip device. OAC and antiplatelet therapy were contraindicated. Mean CHA2DS2-VASc score was 3.61, and the mean HAS-BLED score was 4.42. Successful LAA closure was assessed by transesophageal echocardiography. Primary endpoints were complete LAA closure (no residual LAA flow), operative complications, and all-cause mortality; secondary endpoints were 30-day and 6-month complications (death, ischemic stroke, hemorrhagic stroke, transient ischemic attack, any bleeding). Mean follow-up was 6 ± 4 months. RESULTS: Complete LAA closure was achieved in all patients. No operative clip-related complications or deaths occurred. At follow-up, freedom from postoperative complications was 95% and from any cerebrovascular events was 100%. Overall survival rate was 100%. CONCLUSIONS: In nonvalvular AF patients at high bleeding risk (HAS-BLED score >3), thoracoscopic LAA closure appears to be a valid alternative to percutaneous techniques not requiring dual antiplatelet or OAC treatment. Apparently, external LAA clipping minimizes the risk of thromboembolic events as compared with percutaneous procedures.

Analysis of catheter contact force during atrial fibrillation ablation using the robotic navigation system: results from a randomized study.

PURPOSE: Contact with cardiac tissue is an important determinant of lesion efficacy during atrial fibrillation (AF) ablation. The Sensei X™ robotic navigation system (RNS) (Hansen Medical, Mountain View, CA, USA) has been validated for contact force (CF) sensing expressed in grams (g). The Thermocool® SmartTouch™ catheter enables the measurement of catheter tip CF and direction inside the heart. We aimed to investigate the catheter CF with and without RNS during pulmonary vein isolation (PVI) procedures. METHODS: Eighty patients with symptomatic AF (56 males, age 63 ± 18) were enrolled in this study. Fifty-seven patients had paroxysmal AF and 23 early persistent AF. All procedures were performed with the Thermocool® SmartTouch™ ablation catheter. Forty patients were randomized to perform PVI with the Sensei X™ RNS (group 1), while in the other 40 patients (group 2), PVI was performed without the RNS. RESULTS: AF ablation was performed successfully in all patients without complications, while contact force was kept in the established 10-40 g range. A significantly higher CF was documented on the PVs in group 1 compared to group 2. The 1-year freedom from AF recurrence was higher in group 1 compared to group 2 (90 vs. 65 %, p = 0.04). Moreover, a significant reduction of fluoroscopy time was noted in the RNS group (13 ± 10 vs. 20 ± 10 min, respectively, p = 0.05). CONCLUSIONS: The Sensei X™ RNS permits a significantly higher CF during transcatheter AF ablation with a low rate of AF recurrence at clinical follow-up.

Safety and feasibility of coronary sinus left ventricular leads extraction: a preliminary report.

BACKGROUND: transvenous positioning of the left ventricular (LV) lead in a branch of the coronary sinus (CS) is generally the preferred implantation technique in biventricular pacing. Very few data are reported about removal of LV pacing leads positioned in a CS branch. Aim of the study was to describe our experience with percutaneous extraction of LV pacing leads in order to evaluate feasibility and safety of this procedure. METHODS: we enrolled 392 patients who underwent a biventricular pacing implant. The indication for catheter removal was considered in case of definite diagnosis of infection and in some cases of lead dislodgement or diaphragmatic stimulation. LV lead extraction was first attempted by manual traction; in case of failure a locking stylet or locking stylet plus radiofrequency could be used. RESULTS: twelve of 392 patients implanted needed LV lead removal. The leads had been in place for 13.9 +/- 11.7 months. Extraction was indicated in 5 of them for LV lead dislodgement or diaphragmatic stimulation, and in 7 patients for lead infection. In all cases manual traction succeeded to remove the LV lead. In 7 cases of infection, the right atrial and ventricular leads were removed. The mean total procedure time was 69 +/- 22 min. No complications were observed. CONCLUSIONS: our study suggests that CS leads could be easily and safely removed without any complication, also when placed in a CS branch, at least for relatively young catheters.

Usefulness of intracardiac echocardiography during pulmonary vein isolation with the novel multipolar irrigated ablation catheter (nMARQ™).

BACKGROUND: Previous studies reported the usefulness of an irrigated circular radiofrequency ablation catheter (nMARQ(TM), Biosense Webster) for pulmonary vein isolation (PVI). We evaluated the role of intracardiac echocardiography (ICE) to optimize the manipulation of nMARQ(TM) catheter. METHODS: Thirty-seven patients (pts), (mean age 55 ± 12 years; 28 males) were enrolled to perform PVI. All pts underwent PVI with the nMARQ(TM) catheter. In 20 pts (group 1), we utilized ICE to guide nMARQ(TM) catheter positioning at the PV ostia; in the other 17 pts (group 2), nMARQ(TM) catheter was positioned at the PV ostia guided by fluoroscopy and TissueConnect(TM) technology. RESULTS: Radiofrequency (RF) applications were significantly lower in group 1 compared to group 2 [left PVs: 6 (range 3 to 12) in group 1 and 12 (range 5 to 16) in group 2 (p < 0.001); right PVs: 7 (range 4 to 14) in group 1 and 10 (range 5 to 16) in group 2 (p = 0.04)]; similarly regarding the time of RF delivery [left PVs: 318 ± 194 s in group 1 vs. 542 ± 104 s in group 2 (p < 0.001); right PVs: 410 ± 270 s in group 1 vs. 550 ± 156 s in group 2 (p = 0.05)]. Fluoroscopy time (23 ± 9 min vs. 28 ± 5 min; p = 0.05), procedural time (83 ± 23 min vs. 160 ± 42 min; p < 0.001), and radiation dose (109 ± 20 Gy/cm(2) vs. 127 ± 29 Gy/cm(2); p = 0.04) were significantly lower in group 1 compared to group 2. CONCLUSION: ICE might be a useful tool to guide nMARQ(TM) catheter position in the left atrium during atrial fibrillation (AF) ablation procedures.

A randomized comparison of alternative techniques to achieve coronary sinus cannulation during biventricular implantation procedures.

INTRODUCTION: Biventricular pacing system implantation is a time-consuming and challenging procedure. A critical step in biventricular pacemaker implantation is coronary sinus (CS) cannulation. CS cannulation can be achieved either using dedicated guiding catheters (guiding catheter alone positioning strategy, GCA) or with the aid of an electrophysiology catheter advanced inside the guiding catheter (electrophysiology catheter aided positioning strategy, EPA). AIM OF THE STUDY: To evaluate whether the EPA technique is useful for reducing CS cannulation time compared to a conventional GCA technique. METHODS: Thirty-four consecutive patients were randomly assigned to the GCA (18 patients) or EPA (16 patients) CS cannulation strategy. RESULTS: Time to successful catheterization of CS was 5.0 +/- 2.4 min in the EPA group versus 10.1 +/- 5.4 min in the GCA group p = 0.004. Fluoroscopy time was 4.6 +/- 2.3 min in the EPA group versus 9.2 +/- 4.9 min in the GCA group p = 0.004. Total contrast dye volume to search and engage the CS ostium was 0.0 ml in the EPA group versus 14.3 +/- 3.4 ml in the GCA group p < 0.001. CONCLUSIONS: Cannulation of CS with the adjunct of an electrophysiology catheter to dedicated delivery systems significantly reduces procedural time, fluoroscopy time and contrast dye volume compared to a conventional strategy.

Ablation of paroxysmal and persistent atrial fibrillation with multielectrode phased radiofrequency duty-cycled catheters: long-term results from a large cohort of patients.

BACKGROUND: Catheter ablation is a widely used approach to treat patients with drug refractory paroxysmal atrial fibrillation (PAF) and persistent atrial fibrillation (CAF). The aim of this analysis was to evaluate the long-term safety and efficacy of the multielectrode/phased radiofrequency (RF)/duty-cycled ablation catheters in the treatment of both PAF and CAF in a large cohort of patients. METHODS AND RESULTS: From July 2008 to February 2010, 429 consecutive drug refractory symptomatic patients (mean age 60 ± 12 years old, 58% men, 68% PAF, 32% CAF) were treated. Seventy-five patients had two procedures resulting in a total of 504 procedures (procedure mean time: 62 ± 15 min). Following ablation, 4-day continuous Holter monitoring was done every 3 months. Recurrence was defined as any atrial tachyarrhythmia of more than 30 s. At 3 months 97.4% of patients were off antiarrhythmic drugs. During a mean follow-up of 22 ± 5 months, freedom from AF recurrence was 68.5% (95% CI: 63.8-72.6) and higher for PAF than CAF patients. The risk of AF recurrence in PAF patients increased in the presence of hypertension, dyslipidemia, large left atrial diameter (LAD) and low ejection fraction. For CAF patients, the risk of AF recurrence increased with larger LAD and lower ejection fraction. Complications that resolved prior to discharge were observed in nine patients (2.1%) with no strokes/transient ischemic attacks (TIAs). CONCLUSION: The ablation of symptomatic PAF and CAF with multielectrode phased radiofrequency/duty-cycled ablation catheters shows long-term safety and effectiveness with relatively short procedure times.

Clinical impact of catheter ablation in patients with asymptomatic atrial fibrillation: the IRON-AF (Italian registry on NavX atrial fibrillation ablation procedures) study.

Whether and to what extent patients with asymptomatic atrial fibrillation (AF) would benefit from catheter ablation has not been investigated. This is the first multicenter prospective study reporting on the outcome of catheter ablation in patients with asymptomatic AF. Consecutive patients (n = 545) referred for AF ablation were prospectively enrolled in a multicenter Italian registry. Of these patients, 54 have asymptomatic AF and composed our patient population. At 24 month follow-up, catheter ablation in asymptomatic AF patients resulted to be as safe and effective as in patients with drug refractory symptomatic AF. Our study provides significant insights on the role of AF ablation in asymptomatic patients. Further studies in much larger cohorts are needed to validate our conclusions.

Relationship of quality of life with procedural success of atrial fibrillation (AF) ablation and postablation AF burden: substudy of the STAR AF randomized trial.

BACKGROUND: The Substrate and Trigger Ablation for Reduction of Atrial Fibrillation (STAR AF) trial compared 3 strategies for ablation of high-burden paroxysmal/persistent atrial fibrillation (AF): complex fractionated electrogram ablation (CFE), pulmonary vein isolation (PVI), or a combined approach (PVI with CFE). This subanalysis aimed to identify the effect on quality of life (QOL) conferred by ablation strategy, AF recurrence, and type of AF. METHODS: The STAR AF study (n = 100) found 88%, 68%, and 38% freedom from AF > 30 seconds at 12 months for PVI with CFE, PVI, and CFE approaches, respectively (P = 0.001). QOL was measured before ablation and at 12 months after ablation using the Short-Form Health Survey (SF-36) scale. Transformed scores were calculated for each of the 8 subscales of the SF-36, and also converted to physical health and mental health component scores. RESULTS: There was a significant improvement in physical health (24%) and mental health (19%) component scores from baseline to 12 months after ablation (P < 0.05 for both). Significant QOL improvements were seen for all 3 ablation strategies despite differences in outcome. QOL measurements also improved regardless of AF recurrence, except in patients with an AF burden in the highest quartile (median 27.2 hours per month). AF recurrence independently predicted aggregate QOL score. CONCLUSIONS: QOL after AF ablation improves regardless of procedural outcome. QOL scores were only negatively affected in patients with a high symptomatic burden of arrhythmia recurrence suggesting that significant reduction in AF burden can improve QOL without total elimination of AF.

Catheter ablation of atrial fibrillation guided by a 3D electroanatomical mapping system: a 2-year follow-up study from the Italian Registry On NavX Atrial Fibrillation ablation procedures (IRON-AF).

AIMS: Clinical trials have established that atrial fibrillation (AF) catheter ablation improves symptoms in appropriately selected patients. Confirmation of these results by long-term prospective observational studies is needed. This registry was created to describe the experience of 16 Italian centers with a large cohort of AF patients treated with catheter ablation guided by the NavX 3D mapping system. METHODS: From November 2006 to May 2008, 545 consecutive patients (age 60.4 ± 9.8, 67 % male) with paroxysmal (44 %), persistent (43 %), and long-standing persistent (13 %) AF referred for catheter ablation guided by the NavX system, were included in this registry. For this paper, follow-up was censored at 24 months; however, patients are being followed in the ongoing registry. RESULTS: Before the ablation, 80 % of patients failed to respond to at least one antiarrhythmic drug aimed at rhythm control. Pulmonary vein (PV) isolation guided by a circular mapping catheter was performed in 70 % of patients whereas non potential-guided PV encircling was performed in 30 % of patients. In 67 % of patients, additional left atrial (LA) substrate modification was performed. Image integration was performed in 9.2 % of patients. Considering a 3-month blanking period, after a single-ablation procedure, the patients had 1- and 2-year freedom from AF recurrence of 67.4 and 57.0 % (36.1 % off antiarrhythmic drugs), respectively. Cox regression analysis showed that AF recurrences during blanking (HR 2.1), and previous AF ablation (HR 3.3) were independent predictors of AF recurrences. Major procedure-related complications occurred in 53 patients (9.7 %). In 35 patients (6.7 %), a repeat procedure was performed at a median of 5 months after the initial procedure. CONCLUSIONS: This prospective, multicenter clinical experience provides significant insights into current ablation care of patients with AF. Despite favorable outcomes, real-world complication rates appear higher than previously recognized.

Experimental assessment of level pool routing in preliminary design of floodplain storage.

Among control structures in flood management, floodplain storage represents one of the most effective measures, since it holds part of flood volume in a delimited area thus reducing the peak discharge. Sizing of floodplain storage, both on-stream and off-stream, is complex and several methodologies for preliminary design are available in literature, almost all assuming level pool reservoir routing, i.e. the water level in the floodplain is horizontal during the storage filling. Few studies examine the accuracy of that assumption. The present paper work reports an extensive experimental investigation to assess the reliability of level pool routing in the design of on-stream floodplain storages. The good agreement between numerical and experimental values during the filling phase confirmed the reliability of the hypothesis in the preliminary sizing of on-stream floodplain storage. In contrast, even significant differences can be shown during the floodplain draining, due to vegetation and bottom irregularities.