Posterior wall isolation via a multi-electrode radiofrequency balloon catheter: feasibility, technical considerations, endoscopic findings and comparison with cryoballoon technologies.

BACKGROUND: Posterior wall (PW) isolation is an important adjunctive ablation target in patients with non-paroxysmal atrial fibrillation (AF). Traditionally performed with point-by-point radiofrequency (RF) ablation, PW isolation has also been performed with different cryoballoon technologies. We aimed at assessing the feasibility of PW isolation with the novel RF balloon catheter Heliostar™ (Biosense Webster, CA, USA). METHODS: We prospectively enrolled 32 consecutive patients with persistent AF scheduled for first-time ablation with the Heliostar™ device. Procedural data were compared with those from 96 consecutive persistent AF patients undergoing pulmonary vein (PV) plus PW isolation with a cryoballoon device. The ratio RF balloon/cryoballoon was 1:3 for each operator involved in the study, aiming at avoiding any imbalance related to different experience. RESULTS: Single-shot PV isolation was documented in a significantly higher number of cases with the RF balloon technology compared to cryoballoon ablation (89.8% vs. 81.0%; p = 0.02, respectively). PW isolation was achieved with a similar number of balloon applications between the two groups (11 ± 4 with the RF balloon versus 11 ± 2 with the cryoballoon; p = 0.16), but in a significantly shorter time among RF balloon patients (228 ± 72 s versus 1274 ± 277 s with cryoballoon; p < 0.001). Primary safety endpoint occurred in none of the RF balloon patients versus 5 (5.2%) patients in the cryoballoon group (p = 0.33). Primary efficacy endpoint was achieved in all (100%) RF balloon patients versus 93 (96.9%) cryoballoon ones (p = 0.57). Oesophageal endoscopy did not show any signs of thermal lesions in RF balloon patients with luminal temperature rise. CONCLUSIONS: RF balloon-based PW isolation was safe and promoted shorter procedure times compared to similar cryoballoon-based ablation procedures.

3D mapping challenges in hybrid video-assisted thoracoscopic surgical ablation of Brugada syndrome.

OBJECTIVES: Brugada syndrome is a life-threatening disease with an arrhythmogenic substrate located in the epicardium of right ventricle outflow tract. Therefore, the correct region identification is crucial for a successful ablation procedure. Various mapping techniques can be adopted to elaborate this issue, but they were all initially developed for endovascular use. METHODS: In this study, we analysed 21 consecutive hybrid video-assisted thoracoscopic ablation of Brugada syndrome, performed using different mapping systems to identify the ablation target and confirm the elimination of arrhythmogenic substrate; 35 maps have been analysed. RESULTS: Acute success of epicardial right ventricle outflow tract ablation has been achieved in 100% of procedures, no periprocedural complications have been observed; HD Grid catheter showed higher area identification speed and faster fractionated potentials visualization; Rhythmia system has demonstrated the best map density; Carto 3 system showed a significant advantage in patient preparation time, but mapping speed was reduced due to focal catheter use only. CONCLUSIONS: All tested electro anatomical mapping systems can be used for hybrid video-assisted thoracoscopic ablation with same clinical success; however, accuracy and efficacy of mapping systems are heterogenous and highly dependent on proper patient preparation, mapping system and physician skills.

Predictors of late pulmonary vein reconnection in patients with arrhythmia recurrence after cryoballoon ablation-per vein analysis including cardiac computed tomography-based anatomic factors.

AIMS: To identify predictors of individual late pulmonary vein (PV) reconnection after second-generation cryoballoon (CB2) ablation. Anatomic indicators of late pulmonary vein reconnection (LPVR) post-CB2 ablation have not yet been studied on an individual PV level, nor weighed against clinical and procedural factors. METHODS AND RESULTS: Clinical, procedural, and PV anatomic data from 125 patients with a repeat procedure for arrhythmia recurrence after index CB2 ablation were analyzed. Preprocedural computed tomography (CT) evaluated 486 PVs for measurement of size; shape (ovality index); carina width; and orientation angle in frontal (superior/inferior) and transversal (anterior/posterior) plane (with horizontal line 0° as reference and upper/lower half circle as positive/negative value, respectively). Durable isolation in all PVs was demonstrated in 50/125 (40%) patients. Late reconnection rates at the different PVs were as follows: 16% left superior (LS), 12% left inferior (LI), 17% right superior (RS), and 31% right inferior (RI) PV. Multivariable analysis performed per vein showed following independent determinants predicting LPVR: ovality index [odds ratio (OR) 1.61, 95% confidence interval (CI) 1.07-2.41, P = 0.022] and carina width (OR 0.75, CI 0.59-0.96, P = 0.024) for LSPV; carina width (OR 0.71, CI 0.53-0.95, P = 0.020) for LIPV; frontal angle (OR 0.91, CI 0.87-0.95, P < 0.001) for RIPV; and transversal angle (OR 1.15, CI 1.03-1.31, P = 0.032) for RSPV. CONCLUSION: Cardiac CT-based evaluation of anatomic PV characteristics presented higher predictive value compared to clinical and procedural variables for individual LPVR after CB2 ablation. Pre-procedural identification of unfavourable PV anatomy might be important to tailor the ablation approach.

Síndrome de Brugada: 30 Anos de Aventura Científica / Brugada Syndrome: 30 Years of Scientific Ventures

Resumo Trinta anos atrás, uma nova síndrome clínico-eletrocardiográfica distinta foi descrita, agora conhecida como síndrome de Brugada (SBr). Típico para essa síndrome é o eletrocardiograma com supradesnivelamento do segmento ST nas derivações precordiais direitas. A apresentação clínica da doença é altamente variável: os pacientes podem permanecer completamente assintomáticos, mas também podem desenvolver episódios de síncope, fibrilação atrial (FA), síndrome do nódulo sinusal (SNS), distúrbios de condução, assistolia e fibrilação ventricular (FV). A doença é causada por mutações nos genes responsáveis pelo potencial de ação das células do coração. O gene mais frequentemente envolvido é o SCN5A, que controla a estrutura e função do canal de sódio cardíaco. A descrição dessa nova síndrome teve implicações muito positivas em todos os campos da medicina.

Abstract Thirty years ago, a distinctly new clinical-electrocardiographic syndrome was described, today known as Brugada Syndrome (BrS). Typical treatment for this type of syndrome is electrocardiography with ST-segment elevation in the direct precordial derivations. The clinical presentation of the disease is highly variable: the patients can remain completely asymptomatic, but they can also develop episodes of syncope, atrial fibrillation (AF), sinus node dysfunction (SNF), conduction disorders, asystole, and ventricular fibrillation (VF). This disease is caused by mutations in the genes responsible for the potential action of cardiac cells. The most commonly involved gene is SCN5A, which controls the structure and function of the heart's sodium channel. The description of this new syndrome has shown highly positive implications in all fields of medicine.

Hybrid-Approach Ablation in Drug-Refractory Arrhythmogenic Right Ventricular Cardiomyopathy.

Management of ventricular arrhythmias (VAs) beyond implantable cardioverter-defibrillator positioning in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) is challenging. Catheter ablation of the ventricular substrate often requires a combination of endocardial and epicardial approaches, with disappointing outcomes due to the progressive nature of the disease. We report the Universitair Ziekenhuis Brussel experience through a case series of 16 patients with drug-refractory ARVC, who have undergone endocardial and/or epicardial catheter ablation of VAs with a thoracoscopic hybrid-approach. After a mean follow-up time of 5.16 years (SD 2.9 years) from the first hybrid-approach ablation, VA recurrence was observed in 5 patients (31.25%): among these, patients 4 patients (80%) received a previous ablation and 1 of 11 patients (9.09%) who had a hybrid ablation as first approach had a VA recurrence (80% vs 9.09%; log-rank p = 0.04). Despite the recurrence rate of arrhythmic events, all patients had a significant reduction in the arrhythmic burden after ablation, with a mean of 4.65 years (SD 2.9 years) of freedom from clinically significant arrhythmias, defined as symptomatic VAs or implantable cardioverter-defibrillator-delivered therapies. In conclusion, our case series confirms that management of VAs in patients with ARVC is difficult because patients do not always respond to antiarrhythmic medications and can require multiple invasive procedures. A multidisciplinary approach involving cardiologists, cardiac surgeons, and cardiac electrophysiologists, together with recent cardiac mapping techniques and ablation tools, might mitigate these difficulties and improve outcomes.

Long-Term Outcomes of Pulmonary Vein Isolation in Patients With Brugada Syndrome and Paroxysmal Atrial Fibrillation.

Background Pharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BrS) is challenging. In addition, patients with BrS with an implantable cardioverter-defibrillator (ICD) might experience inappropriate shocks for fast AF. Long-term outcome of pulmonary vein isolation in BrS has not been well established yet, and it is still unclear whether pulmonary vein triggers are the only pathophysiological mechanism of AF in BrS. The aim of the study is to assess the long-term outcomes in patients with BrS undergoing pulmonary vein isolation for paroxysmal AF compared with a matched cohort of patients without BrS. Methods and Results Sixty patients with BrS undergoing pulmonary vein isolation with cryoballoon catheter ablation for paroxysmal AF were matched with 60 patients without BrS, who underwent the same procedure. After a mean follow-up of 58.2±31.7 months, freedom from atrial tachyarrhythmias was achieved in 61.7% in the BrS group and in 78.3% in the non-BrS group (log-rank P=0.047). In particular, freedom from AF was 76.7% in the first group and in 83.3% in the second (P=0.27), while freedom from atrial tachycardia/atrial flutter was 85% and 95% (P=0.057). In the BrS group, 29 patients (48.3%) had an ICD and 8 (27.6%) had a previous ICD-inappropriate shock for fast AF. In the BrS cohort, ICD-inappropriate interventions for AF were significantly reduced after ablation (3.4% versus 27.6%; P=0.01). Conclusions Pulmonary vein isolation in patients with BrS was associated with higher rate of arrhythmic recurrence. Despite this, catheter ablation significantly reduced inappropriate ICD interventions in BrS patients and can be considered a therapeutic strategy to prevent inappropriate device therapies.

Feasibility and safety of left atrial posterior wall isolation with a new Cryoballoon technology in patients with persistent atrial fibrillation.

BACKGROUND: Left atrial posterior wall isolation (LAPWI) is often performed in addition to pulmonary vein isolation (PVI) in the setting of persistent atrial fibrillation (AF) ablation. The aim of this study was to evaluate the feasibility and safety of a new cryoballoon ablation system in achieving PVI + LAPWI isolation. METHODS: The study was a prospective, non-randomized, single center study. Forty consecutive patients, undergoing PVI + LAPWI with the novel POLARx™, were compared to 40 consecutive patients who underwent the same procedure with the established Arctic Front Advance PRO™. RESULTS: Acute isolation was achieved in all PVs in both groups and left posterior wall isolation (LAPWI) was achieved in 38 patients (95%) in the POLARx group and in 36 patients (90%) in Arctic Front group. Procedural outcomes were similar between both groups, except for lower temperatures during cryoenergy in the POLARx group, for both pulmonary vein isolation (PVI) and LAPWI. CONCLUSION: LAPWI + PVI with the novel POLARx™ Cryoballoon is feasible and safe; the results are comparable with the Arctic Front Advance PRO™ system.

Single procedural outcomes in the setting of percutaneous ablation for persistent atrial fibrillation: a propensity-matched score comparison between different strategies.

BACKGROUND: Catheter ablation for persistent atrial fibrillation (persAF) is associated with less favorable outcomes than for paroxysmal AF. To improve success rates, left atrial (LA) substrate modification is frequently performed in addition to pulmonary vein isolation (PVI). The purpose of the study was to compare 4 different ablation approaches using radiofrequency catheter ablation (RFCA) or cryoballoon ablation (CB-A) for persAF and to evaluate the respective outcomes on a midterm follow-up of 12 months. METHODS: We did a propensity score-matched comparison of 30 patients undergoing PVI + LA posterior wall isolation (LAPWI) with CB-A, 30 patients who underwent PVI + linear ablation (roof and mitral lines) using RFCA, 60 patients with PVI alone using CB-A, and 60 patients who had PVI alone using RFCA. The endpoint was recurrence of documented atrial tachyarrhythmias (ATas) > 30 s at 1-year follow-up. RESULTS: After 12 months, freedom from ATas after a single procedure was 83.3% in the PVI + LAPWI group, 46.7% in the PVI + linear ablation group, 58.3% in the PVI-alone CB-A group, and 61.6% PVI-alone RFCA (p = 0.03). Moreover, freedom from ATas was significantly higher comparing the PVI + LAPWI group with each of the other groups. CONCLUSIONS: In this propensity-matched comparison of strategies for persAF, LAPW ablation in addition to PVI with CB-A seems to improve 1-year outcome in comparison to PVI + linear ablation using RFCA and to PVI alone using RFCA or CB-A. Randomized comparisons are eagerly awaited.

Sinus node sparing novel hybrid approach for treatment of inappropriate sinus tachycardia/postural sinus tachycardia: multicenter experience.

BACKGROUND: The ideal treatment of inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) still needs to be defined. Medical treatments yield suboptimal results. Endocardial catheter ablation of the sinus node (SN) may risk phrenic nerve damage and open-heart surgery may be accompanied by unjustified invasive risks. METHODS: We describe our first multicenter experience of 255 consecutive patients (235 females, 25.94 ± 3.84 years) having undergone a novel SN sparing hybrid thoracoscopic ablation for drug-resistant IST (n = 204, 80%) or POTS (n = 51, 20%). As previously described, the SN was identified with 3D mapping. Surgery was performed through three 5-mm ports from the right side. A minimally invasive approach with a bipolar radiofrequency clamp was used to ablate targeted areas while sparing the SN region. The targeted areas included isolation of the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected. RESULTS: Normal sinus rhythm (SR) was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months, all patients presented stable SR. At a mean of 4.07 ± 1.8 years, normal SN reduction and chronotropic response to exercise were present. In the 51 patients initially diagnosed with POTS, no syncope occurred. During follow-up, pericarditis was the most common complication (121 patients: 47%), with complete resolution in all cases. Pneumothorax was observed in 5 patients (1.9%), only 3 (1.1%) required surgical drainage. Five patients (1.9%) required a dual-chamber pacemaker due to sinus arrest > 5 s. CONCLUSIONS: Preliminary results of this multicenter experience with a novel SN sparing hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with simultaneous endocardial 3D mapping may prove to be an efficient and safe therapeutic option in patients with symptomatic drug-resistant IST and POTS. Importantly, in our study, all patients had a complete resolution of the symptoms and restored normal SN activity.

High vagal tone predicts pulmonary vein reconnection after cryoballoon ablation for paroxysmal atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) isolation is an established treatment for paroxysmal drug-refractory atrial fibrillation (AF). High parasympathetic tone and reconnection of PVs have demonstrated to be possible culprits of AF recurrence after ablation. Our aim was to investigate the association between parasympathetic tone and reconnected PVs in patients with paroxysmal AF. METHODS: Consecutive patients who underwent a redo catheter ablation procedure for atrial tachyarrhythmia recurrence by means of 3D electroanatomic mapping with documentation of presence or absence of PVs reconnection following an initial procedure of cryoballoon (CB) ablation for symptomatic drug-refractory paroxysmal AF were screened for the study. RESULTS: A total of 92 patients were included, of whom 50 (54.35%) were males. Reconnected PVs were found in 64 (69%) patients. PVs reconnection could be predicted by DC (C-statistic = .770), by SDNNI (C-statistic = .714) and by absolute VLF power (C-statistic = .722), while right-sided PVs reconnection could be better predicted by DC (C-statistic = .848) and by SDNNI (C-statistic = .761). In multivariate binary logistic regression analysis, a DC value ≥6.45 ms and an absolute VLF power value ≥160 ms2 were associated with three times and five times higher odds of PVs reconnection, respectively. On a vein-per-vein analysis, absolute VLF power ≥160 ms2 was associated with three times higher odds, while reaching of -40°C within 60 s was associated with three times lower odds of PVs reconnection. CONCLUSION: High parasympathetic tonus accurately predicts PVs reconnection. On a vein-per-vein analysis, parasympathetic markers along with biophysical parameters predicted PVs reconnection. On a case-by-case analysis, parasympathetic markers were the only predictors of PVs reconnection, thus being a robust PVs reconnection prediction tool.

Brugada syndrome: current concepts and genetic background / Síndrome de Brugada: conceitos atuais e antecedentes genéticos

BACKGROUNG: Brugada syndrome (BrS) is a hereditary clinical-electrocardiographic arrhythmic entity with low worldwide prevalence. The syndrome is caused by changes in the structure and function of certain cardiac ion channels and reduced expression of Connexin 43 (Cx43) in the Right Ventricle (RV), predominantly in the Right Ventricular Outflow Tract (VSVD), causing electromechanical abnormalities. The diagnosis is based on the presence of spontaneous or medicated ST elevation, characterized by boost of the J point and the ST segment ≥2 mm, of superior convexity "hollow type" (subtype 1A) or descending rectilinear model (subtype 1B). BrS is associated with an increased risk of syncope, palpitations, chest pain, convulsions, difficulty in breathing (nocturnal agonal breathing) and/or Sudden Cardiac Death (SCD) secondary to PVT/VF, unexplained cardiac arrest or documented PVT/VF or Paroxysmal atrial fibrillation (AF) in the absence of apparent macroscopic or structural heart disease, electrolyte disturbance, use of certain medications or coronary heart disease and fever. In less than three decades since the discovery of Brugada syndrome, the concept of Mendelian heredity has come undone. The enormous variants and mutations found mean that we are still far from being able to concretely clarify a genotype-phenotype relationship. There is no doubt that the entity is oligogenetic, associated with environmental factors, and that there are variants of uncertain significance, especially the rare variants of the SCN5A mutation, with European or Japanese ancestors, as well as a spontaneous type 1 or induced pattern, thanks to gnomAD (coalition) researchers who seek to aggregate and harmonize exome and genome sequencing data from a variety of large-scale sequencing projects and make summary data available to the scientific community at large). Thus, we believe that this in-depth analytical study of the countless mutations attributed to BrS may constitute a real cornerstone that will help to better understand this intriguing syndrome.

INTRODUÇÃO: A Síndrome de Brugada (SBr) é uma entidade arrítmica clínico-eletrocardiográfica hereditária com baixa prevalência mundial. A síndrome é causada por alterações na estrutura e função de certos canais iônicos cardíacos e redução da expressão da Connexina 43 (Cx43) no Ventrículo Direito (VD), predominantemente no Trato de Saída do Ventricular Direito (VSVD), causando anormalidades eletromecânicas. O diagnóstico é baseado na presença de supradesnivelamento de ST espontâneo ou medicamentoso caracterizado por supradesnivelamento do ponto J e do segmento ST ≥2 mm, de convexidade superior "tipo covado" (subtipo 1A) ou modelo retilíneo descendente (subtipo 1B). A SBr está associado a um risco aumentado de síncope, palpitações, dor precordial, convulsões, dificuldade em respirar (respiração agonal noturna) e/ou Morte Cardíaca Súbita (MSC) secundária a PVT/VF, parada cardíaca inexplicada ou PVT/VF documentado ou Fibrilação atrial paroxística (FA) na ausência de doença cardíaca macroscópica ou estrutural aparente, distúrbio eletrolítico, uso de certos medicamentos ou coração coronário e febre. Em menos de três décadas desde a descoberta da síndrome de Brugada, o conceito de hereditariedade mendeliana se desfez. As enormes variantes e mutações encontradas significam que ainda estamos longe de sermos capazes de esclarecer concretamente uma relação genótipo-fenótipo. Não há dúvida de que a entidade é oligogenética associada a fatores ambientais, e que há variantes de significado incerto, principalmente as raras variantes da mutação SCN5A, com ancestrais europeus ou japoneses, bem como padrão espontâneo tipo 1 ou induzido, graças ao gnomAD (coalizão de pesquisadores que buscam agregar e harmonizar dados de sequenciamento de exoma e genoma de uma variedade de projetos de sequenciamento em grande escala e disponibilizar dados resumidos para a comunidade científica em geral). As enormes variantes e mutações encontradas significam que ainda estamos longe de sermos capazes de esclarecer concretamente uma relação genótipo-fenótipo. Assim, acreditamos que este estudo analítico em profundidade das inúmeras mutações atribuídas à BrS pode constituir uma verdadeira pedra angular que ajudará a compreender melhor esta síndrome intrigante.

Short P-Wave Duration is a Marker of Higher Rate of Atrial Fibrillation Recurrences after Pulmonary Vein Isolation: New Insights into the Pathophysiological Mechanisms Through Computer Simulations.

Background Short ECG P-wave duration has recently been demonstrated to be associated with higher risk of atrial fibrillation (AF). The aim of this study was to assess the rate of AF recurrence after pulmonary vein isolation in patients with a short P wave, and to mechanistically elucidate the observation by computer modeling. Methods and Results A total of 282 consecutive patients undergoing a first single-pulmonary vein isolation procedure for paroxysmal or persistent AF were included. Computational models studied the effect of adenosine and sodium conductance on action potential duration and P-wave duration (PWD). About 16% of the patients had a PWD of 110 ms or shorter (median PWD 126 ms, interquartile range, 115 ms-138 ms; range, 71 ms-180 ms). At Cox regression, PWD was significantly associated with AF recurrence (P=0.012). Patients with a PWD <110 ms (hazard ratio [HR], 2.20; 95% CI, 1.24-3.88; P=0.007) and patients with a PWD ≥140 (HR, 1.87, 95% CI, 1.06-3.30; P=0.031) had a nearly 2-fold increase in risk with respect to the other group. In the computational model, adenosine yielded a significant reduction of action potential duration 90 (52%) and PWD (7%). An increased sodium conductance (up to 200%) was robustly accompanied by an increase in conduction velocity (26%), a reduction in action potential duration 90 (28%), and PWD (22%). Conclusions One out of 5 patients referred for pulmonary vein isolation has a short PWD which was associated with a higher rate of AF after the index procedure. Computer simulations suggest that shortening of atrial action potential duration leading to a faster atrial conduction may be the cause of this clinical observation.

Comparison between superior vena cava ablation in addition to pulmonary vein isolation and standard pulmonary vein isolation in patients with paroxysmal atrial fibrillation with the cryoballoon technique.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) can be triggered by non-pulmonary vein foci, like the superior vena cava (SVC). The latter is correlated with improved result in terms of freedom from atrial tachycardias (ATs), when electrical isolation of this vessel utilizing radiofrequency energy (RF) is achieved. OBJECTIVES: Evaluate the clinical impact, in patients with PAF, of the SVC isolation (SVCi) in addition to ordinary pulmonary vein isolation (PVI) by means of the second-generation cryoballoon (CB) METHODS: A total of 100 consecutive patients that underwent CB ablation for PAF were retrospectively selected. Fifty consecutive patients received PVI followed by SVCi by CB application, and the following 50 consecutive patients received standard PVI. All patients were followed 12 months. RESULTS: The mean time to SVCi was 36.7 ± 29.0 s and temperature at SVC isolation was - 35 (- 18 to - 40) °C. Real-time recording (RTR) during SVCi was observed in 42 (84.0%) patients. At the end of 12 months of follow-up, freedom from ATs was achieved in 36 (72%) patients in the PVI only group and in 45 (90%) patients of the SVC and PV isolation group (Fisher's exact test p = 0.039, binary logistic regression: p = 0.027, OR = 0.28, 95%CI = 0.09-0.86). In survival analysis, SVC and PV isolation group was also associated with improved freedom from ATs (log-rank test: p = 0.017, Cox regression: p = 0.026, HR = 0.31, 95%CI = 0.11-0.87). CONCLUSION: Superior vena cava isolation with the CB in addition to PVI might improve freedom from ATs if compared to PVI alone at 1-year follow-up.

Long-term durability of posterior wall isolation using the cryoballoon in patients with persistent atrial fibrillation: a multicenter analysis of repeat catheter ablations.

PURPOSE: There is a growing interest in performing pulmonary vein isolation (PVI) with concomitant posterior wall isolation (PWI) using the cryoballoon for the treatment of patients with persistent atrial fibrillation (AF). However, there is little known about the long-term durability of PWI using this approach. METHODS: In this multicenter study, we retrospectively examined the durability of PVI + PWI using the 28-mm cryoballoon by investigating the outcomes from consecutive patients referred for repeat catheter ablation. RESULTS: Altogether, 81/519 patients (15.6%) were referred for repeat catheter ablation. Repeat ablation was associated with a longer AF duration, hypertension, heart failure, multiple cardioversions, and antiarrhythmic therapy as well as larger left atrial (LA) diameters (49 ± 4 mm versus 43 ± 5 mm; P < 0.001) and greater need for "touch-up" (adjunct) radiofrequency ablation (44.4% versus 18.3%; P < 0.001). LA diameter also emerged as a significant predictor for adjunct radiofrequency ablation (P < 0.001). Durable PVI was observed in 66/81 patients (81.5%) and PWI in 67/81 patients (82.7%). Those with incomplete PWI exhibited larger LA diameters, particularly > 48 mm (negative predictive value = 89.7%). Lastly, an atypical LA posterior wall/roof flutter represented the third most common cause of arrhythmia recurrence and essentially every patient with incomplete PWI exhibited such an arrhythmia. CONCLUSION: PWI performed using a 28-mm cryoballoon in conjunction with PVI exhibits long-term durability in the vast majority of patients with persistent AF. While LA diameter (particularly > 48 mm) is a significant predictor for the need for adjunct radiofrequency ablation when performing this technique, those with incomplete PWI invariably present with an atypical flutter using this substrate.

Phrenic nerve palsy during right-sided pulmonary veins cryoapplications: new insights from pulmonary vein anatomy addressed by computed tomography.

PURPOSE: There is still sparse information regarding phrenic nerve palsy (PNP) during the cryoablation of both right-sided pulmonary vein (PV) and its anatomical predictors. METHODS: Consecutive patients who had undergone pulmonary vein isolation (PVI) using CB-A and suffered PNP during both right-sided PVs were retrospectively included in our study. Two other groups were then selected among patients who experienced PNP during RIPV application only (group 2) and RSPV application only (group 3). RESULTS: The incidence of PNI during both right-sided PVs cryoapplications was 2.1%, (32 of 1542 patients). There were no significant clinical differences between the 3 groups. Time from basal temperature to -40 °C significantly differed among the groups for both RIPV (p = 0.0026) and RSPV applications (p = 0.0382). Patients with PNP occurring during RSPV applications had significantly larger RSPV cross-sectional area compared to patients without PNP (p = 0.0116), while in patients with PNP during RIPV application, the angle of RIPV ostium on the transverse plane was significantly smaller compared to patients without PNP (p = 0.0035). The carina width was significantly smaller in patients with PNP occurring during both right-sided PVs cryoapplications compared to patients in which PNP occurred only during one right-sided PV application (p < 0.0001); a cutoff value of 8.5 mm had a sensitivity of 87.3% and a specificity of 75.0%. CONCLUSION: PNP in both right-sided PVs applications is a complication that occurred in 2.1% of cases during CB-A. Pre-procedural evaluation of right PVs anatomy might be useful in evaluating the risk of PNP.

Long-term clinical outcomes after single freeze cryoballoon ablation for paroxysmal atrial fibrillation: a 5-year follow-up.

BACKGROUND: The second-generation cryoballoon ablation (CB-A) has been proven to be safe and effective for pulmonary vein (PV) isolation. Little is known regarding the long-term outcome following CB-A ablation for paroxysmal atrial fibrillation (AF). The aim of the study was to evaluate the freedom from atrial arrhythmias during a 5-year follow-up period among consecutive patients having undergone PV isolation with the CB-A for paroxysmal AF METHODS AND RESULTS: A total of 208 consecutive patients having undergone index PV isolation using CB-A (138 males, 66%; mean age 59.0 ± 12.6 years) were included in our retrospective analysis. Follow-up was based on outpatient clinic visits including Holter electrocardiograms. Recurrence of atrial tachyarrhythmias was defined as a symptomatic or documented episode of > 30 s. At a median follow-up of 62 months, freedom from atrial arrhythmias after a single procedure was achieved in 57.2% of patients. Multivariate analysis demonstrated that obesity, left atrial diameter, and duration of symptoms before AF ablation were independent predictors of ATas recurrences. Major complications occurred in 2.4% of patients. CONCLUSIONS: The present study found a 5-year single-procedure success rate of 57.2% following CB-A ablation procedure. Obesity, higher LA dimensions, and longer duration of symptoms before ablation independently predicted the outcome.

Posterior box isolation as an adjunctive ablation strategy with the second-generation cryoballoon for paroxysmal atrial fibrillation: a comparison with standard cryoballoon pulmonary vein isolation.

PURPOSE: The purpose of the study was to evaluate the impact of left atrial posterior wall isolation (LAPWI) in addition to pulmonary vein isolation (PVI) vs PVI alone, performed using CB-A, in patients with PAF on a midterm follow-up of 12 months. METHODS: Eighty consecutive patients indicated to index cryoballoon ablation (CB-A) for the treatment of drug resistant PAF were included. The first 50 (62.5%) underwent PVI only, and the following 30 patients (37.5%) underwent LAPWI + PVI. RESULTS: Acute isolation was achieved in all PVs in both groups. The LAPW was successfully isolated in 29 out of 30 (97%) patients; in the remaining patient, adjunct radiofrequency ablation was required. The total procedure time and the mean fluoroscopy time were significantly shorter in patients who underwent PV isolation only (p < 0.001). The freedom from atrial fibrillation (AF) at 12 months was not significantly different between the 2 groups (LAPW + PVI = 90% vs PVI = 88%) (log-rank p = 0.816). CONCLUSION: LAPW ablation in addition to PVI by the means of CB-A does not seem to reduce the risk of AF recurrence if compared with the standard PVI on a midterm follow-up of 12 months.

Safety and feasibility of electrical isolation of the superior vena cava in addition to pulmonary vein ablation for paroxysmal atrial fibrillation using the cryoballoon: lessons from a prospective study.

PURPOSE: The purpose of this study was to evaluate the feasibility and safety of superior vena cava (SVC) isolation in addition to standard pulmonary vein isolation (PVI) using the second-generation cryoballoon (CB) in patients with paroxysmal atrial fibrillation. METHODS: Thirty-seven consecutive patients that underwent CB ablation for paroxysmal atrial fibrillation (PAF) were prospectively enrolled in our study. After PVI the SVC was mapped for potentials. If the SVC exhibited electrical activity, isolation was achieved performing a single 180-s balloon application. RESULTS: Regarding SVC isolation, 180-s freeze in the SVC could be completed in 32 (86.4%) patients, and 5 patients had at least 120 s of freezing application (13.5%). Real-time recording during SVC isolation was observed in 30 (81.0%) patients. The mean time to isolation was 36.9 ± 28.7 s and the temperature at isolation was - 33 (- 15 to - 40) °C. No cases developed persistent phrenic nerve palsy (PNP) or any other complication. CONCLUSIONS: Superior vena cava isolation proved to be safe and feasible with the second generation cryoballoon in a prospective series of patients affected by PAF.

Temperature-guided ablation with the second-generation cryoballoon for paroxysmal atrial fibrillation: 3-year follow-up in a multicenter experience.

PURPOSE: A strategy based on the attainment of the specific parameter of - 40 °C within the first 60 s during cryoenergy applications in the setting of cryoballoon ablation (CB-A) without the use of an inner lumen mapping catheter (ILMC) (Achieve; Medtronic, USA) for the visualization of real-time recordings (RTR) has been previously described. The latter has proven to be very effective in guaranteeing freedom from atrial arrhythmias in patients affected by paroxysmal atrial fibrillation (PAF) at 1-year follow-up. The purpose of this retrospective observational study was to evaluate the clinical outcomes of this strategy in a multicenter experience on a long-term follow-up of 3 years. METHODS: A total of 192 patients having undergone CB ablation for paroxysmal AF (PAF) starting from September 2015 to November 2016 that underwent a temperature-guided approach were included. RESULTS: Mean procedural time was 68.77 ± 18.88. The mean number of freezes in the LSPV was 1.2 ± 0.4, 1.2 ± 0.4 in the LIPV, 1.1 ± 0.4 in the RSPV, and 1.2 ± 0.4 in the RIPV. Considering a blanking period of 3 months, freedom from AF off-AAD was achieved in 77.6% (149/192) at mean 34.5 ± 5.5 months and median 35.1 months (IQR, 32.3-37.0 months) follow-up after 1 procedure. CONCLUSIONS: A temperature-guided approach affords freedom from AF at a 3-year follow-up period in a large majority of patients affected by PAF having undergone a single CB-A procedure.