Comparison between the novel diamond temp and the classical 8-mm tip ablation catheters in the setting of typical atrial flutter.

PURPOSE: Radiofrequency (RF) catheter ablation is widely accepted as a first-line therapy for cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL). The novel DiamondTemp (DT) catheter with temperature feedback during RF ablation has been released recently on the market. The purpose of this study was to evaluate the impact of DiamondTemp (DT) technology on ablation efficiency during AFL. METHODS: In this single-center study, 30 consecutive patients with typical AFL indicated to ablation of CTI were included. The first 15 patients underwent CTI ablation using 8-mm tip catheter, and the following 15 patients underwent temperature-controlled RF ablation using DT catheter. The endpoints were number and mean total duration of RF applications, mean temperature reached in the setting of CTI, procedural times, and fluoroscopy times. RESULTS: There were no significant differences between the two groups concerning baseline characteristics. Mean duration of the each application (71.5 s ± 30.6 vs 12.4 s ± 13.2, p value < 0.001), mean total duration of RF applications (517,73 s ± 377,96 vs 112,8 s ± 43,58; p value < 0.001), procedural times (51.6 min ± 24.2 vs 38.6 ± 8.2; p = 0.03), and fluoroscopy times (16.2 min ± 10.2 vs 8 min ± 4.24; p = 0.005) were longer in the 8-mm ablation catheter group. Mean temperature measurements (51.9 °C ± 3.59 vs 56.7 °C ± 3.34, p value < 0.003) were as well lower in the 8-mm ablation catheter group. CONCLUSIONS: Catheter ablation of CTI-dependent AFL by means of DT resulted in a significant reduction of total and single application RF delivery time, procedure, and fluoroscopy times.

Procedural Safety and Efficacy for Pulmonary Vein Isolation with the Novel Polarx™ Cryoablation System: A Propensity Score Matched Comparison with the Arctic Front™ Cryoballoon in the Setting of Paroxysmal Atrial Fibrillation.

BACKGROUND: The novel Polarx™ cryoablation system is currently being studied for atrial fibrillation (AF) ablation. To the best of our knowledge, no study comparing the novel cryoablation system with the standard Arctic Front™ cryoballoon is available in today's literature. This study aims to compare Polarx™ and Arctic Front™ cryoballoon in terms of safety and efficacy. METHODS: From a total cohort of 202 patients who underwent pulmonary vein (PV) isolation for paroxysmal AF through cryoablation, a population of 30 patients who used Polarx™ were compared with 30 propensity-score matched patients who used Arctic Front™. RESULTS: Pulmonary vein occlusion and electrical isolation were achieved in all (100%) veins with a mean number of 1.09 ± 0.3 occlusion per vein using Polarx™ and 1.19 ± 0.5 occlusion per vein using Arctic Front™ (p = 0.6). Shorter procedure and fluoroscopy time were observed with Polarx™ group (60.5 ± 14.23 vs 73.43 ± 13.26 mins, p = 0.001; 12.83 ± 6.03 vs 17.23 ± 7.17 mins, p = 0.01, respectively). Lower cumulative freeze duration per vein was also observed with Polarx™ (203.38 ± 72.03 vs 224.9 ± 79.35 mins, p = 0.02). There was no significant difference in isolation time between the two groups (34.47 ± 21.23 vs 34.18 ± 26.79 secs, p = 0.9). CONCLUSIONS: The novel Polarx™ cryoablation system showed similar efficacy in vein occlusion and isolation and safety profile when compared to Arctic Front™ cryoablation system. Procedure time, fluoroscopy time, and cumulative freeze duration were significantly lower with Polarx™ cryoablation system.

Mortality Rate and Predictors Among Patients with COVID-19 Related Acute Respiratory Failure Requiring Mechanical Ventilation: a Retrospective Single Centre Study.

AIM: The objective of the study was to assess mortality rates in COVID-19 patients suffering from acute respiratory distress syndrome (ARDS) who also requiring mechanical ventilation. The predictors of mortality in this cohort were analysed, and the clinical characteristics recorded. MATERIAL AND METHOD: A single centre retrospective study was conducted on all COVID-19 patients admitted to the intensive care unit of the Epicura Hospital Center, Province of Hainaut, Belgium, between March 1st and April 30th 2020. RESULTS: Forty-nine patients were included in the study of which thirty-four were male, and fifteen were female. The mean (SD) age was 68.8 (10.6) and 69.5 (12.6) for males and females, respectively. The median time to death after the onset of symptoms was eighteen days. The median time to death, after hospital admission was nine days. By the end of the thirty days follow-up, twenty-seven patients (55%) had died, and twenty-two (45%) had survived. Non-survivors, as compared to those who survived, were similar in gender, prescribed medications, COVID-19 symptoms, with similar laboratory test results. They were significantly older (p = 0.007), with a higher co-morbidity burden (p = 0.026) and underwent significantly less tra-cheostomy (p < 0.001). In multivariable logistic regression analysis, no parameter significantly predicted mortality. CONCLUSIONS: This study reported a mortality rate of 55% in critically ill COVID-19 patients with ARDS who also required mechanical ventilation. The results corroborate previous findings that older and more comorbid patients represent the population at most risk of a poor outcome in this setting.

Repositioning and extraction of stylet-driven pacing leads with extendable helix used for left bundle branch area pacing.

Conventional stylet-driven leads with extendable helix can be implanted successfully for left bundle branch area pacing (LBBAP) with a low acute complication rate. We report two cases in which lead repositioning after a first unsuccessful attempt to LBBAP was associated with fracture of the helix rotating mechanism and failure to fully extract the pacing lead.

Real world data on non-complex catheter ablations performed on zero fluoroscopy in a secondary centre in the south of Belgium.

OBJECTIVE: We have designed a study, whose aim was to confirm the feasibility and safety of the zero fluoroscopy approach in the treatment of supraventricular tachycardias (SVT) and premature ventricular contractions (PVCs) originating in the right ventricle in a secondary centre located in the south of Belgium. METHODS: We included in our retrospective analysis patients with a clinical history and/or electrocardiographic documentation of SVT or frequent symptomatic monomorphic PVCs referred to our centre from November 2019 to March 2020 for catheter ablation. RESULTS: A total of 49 patients were considered eligible for potential enrolment in the study, 3 were excluded because of presence of a manifest left sided atrio-ventricular accessory pathway, 5 because of left ventricular PVCs and 4 because of left atrial tachycardia. 4 patients were instead excluded because of need of utilisation of fluoroscopy during the procedure. A total of 33 patients were therefore included in the analysis. Right atrial flutters and typical AVNRT were the most common arrhythmia treated, corresponding together to the 81% of the total. Right femoral access was obtained in 86% of cases with left femoral access used in the remaining when right femoral access was not successful after the third attempt. Coronary sinus cannulation was efficacious within 10 min in 76% of cases. There were four minor complications overall. CONCLUSION: The main finding of our study is that non-complex ablations can be performed on zero-fluoroscopy safely and with a good clinical outcome also in a secondary centre.

Predictive Accuracy of COVID-19 World Health Organization (WHO) Severity Classification and Comparison with a Bayesian-Method-Based Severity Score (EPI-SCORE).

Assess the predictive accuracy of the WHO COVID-19 severity classification on COVID-19 hospitalized patients. The secondary aim was to compare its predictive power with a new prediction model, named COVID-19 EPI-SCORE, based on a Bayesian network analysis. Methods: We retrospectively analyzed a population of 295 COVID-19 RT-PCR positive patients hospitalized at Epicura Hospital Center, Belgium, admitted between March 1st and April 30th, 2020. Results: Our cohort's median age was 73 (62-83) years, and the female proportion was 43%. All patients were classified following WHO severity classification at admission. In total, 125 (42.4%) were classified as Moderate, 69 (23.4%) as Severe, and 101 (34.2%) as Critical. Death proportions through these three classes were 11.2%, 33.3%, and 67.3%, respectively, and the proportions of critically ill patients (dead or needed Invasive Mechanical Ventilation) were 11.2%, 34.8%, and 83.2%, respectively. A Bayesian network analysis was used to create a model to analyze predictive accuracy of the WHO severity classification and to create the EPI-SCORE. The six variables that have been automatically selected by our machine learning algorithm were the WHO severity classification, acute kidney injury, age, Lactate Dehydrogenase Levels (LDH), lymphocytes and activated prothrombin time (aPTT). Receiver Operation Characteristic (ROC) curve indexes hereby obtained were 83.8% and 91% for the models based on WHO classification only and our EPI-SCORE, respectively. Conclusions: Our study shows that the WHO severity classification is reliable in predicting a severe outcome among COVID-19 patients. The addition to this classification of a few clinical and laboratory variables as per our COVID-19 EPI-SCORE has demonstrated to significantly increase its accuracy.

Conversion of atrial fibrillation to sinus rhythm during cryoballoon ablation: A favorable and not unusual phenomenon during second-generation cryoballoon pulmonary vein isolation.

BACKGROUND: The prevalence and the clinical impact of conversion of atrial fibrillation (AF) to sinus rhythm (SR) during cryoballoon ablation (CB-A) are unknown. OBJECTIVE: The purpose of this study was to evaluate the prevalence of restoration of SR during CB-A and the clinical impact of this phenomenon. METHODS: Between January 2012 and September 2018, all patients who experienced conversion of AF to SR during CB-A were included. This group was subsequently matched for gender, age, type of AF, diagnosis-to-ablation time, and left atrial size with patients who underwent CB-A and did not experienced conversion of AF to SR. After discharge, patients were scheduled for follow-up visits at 1, 3, 6, and 12 months and 24 hours Holter recordings were obtained at each follow-up visit. All documented AF episodes of >30 seconds were considered as recurrence. A 3 month post-procedural blanking period (BP) was applied. RESULTS: A total of 1559 patients underwent pulmonary veins isolation by CB-A between January 2012 and September 2018; among them, 58 patients (3.7%) experienced restoration of SR during CB-A. In total, 53 patients (41 males [77.3%], mean age 61.4 ± 13.3 years) were included in the case group. During CB-A, restoration of SR occurred more frequently during right-side PVs applications (right inferior pulmonary vein 39.6%, right superior pulmonary vein 30.2%). If considering a BP, at 2 year follow-up, freedom from recurrences was 86.5% in the case group and 68.0% in the control group (P = .036). CONCLUSION: Conversion of AF to SR is a favorable and relatively frequent phenomenon during cryoballoon pulmonary vein isolation ablation.

Biophysical Investigation of Sodium Channel Interaction with ß-Subunit Variants Associated with Arrhythmias.

Background: Voltage-gated sodium (NaV) channels help regulate electrical activity of the plasma membrane. Mutations in associated subunits can result in pathological outcomes. Here we examined the interaction of NaV channels with cardiac arrhythmia-linked mutations in SCN2B and SCN4B, two genes that encode auxiliary ß-subunits. Materials and Methods: To investigate changes in SCN2B R137H and SCN4B I80T function, we combined three-dimensional X-ray crystallography with electrophysiological measurements on NaV1.5, the dominant subtype in the heart. Results: SCN4B I80T alters channel activity, whereas SCN2B R137H does not have an apparent effect. Structurally, the SCN4B I80T perturbation alters hydrophobic packing of the subunit with major structural changes and causes a thermal destabilization of the folding. In contrast, SCN2B R137H leads to structural changes but overall protein stability is unaffected. Conclusion: SCN4B I80T data suggest a functionally important region in the interaction between NaV1.5 and ß4 that, when disrupted, could lead to channel dysfunction. A lack of apparent functional effects of SCN2B R137H on NaV1.5 suggests an alternative working mechanism, possibly through other NaV channel subtypes present in heart tissue. Indeed, mapping the structural variations of SCN2B R137H onto neuronal NaV channel structures suggests altered interaction patterns.

Mid-term outcome following second-generation cryoballoon ablation for atrial fibrillation in heart failure patients: effectiveness of single 3-min freeze cryoablation performed in a cohort of patients with reduced left ventricular systolic function.

PURPOSE: Currently, information on the mid-term outcome of cryoballoon ablation (CB-A) for drug-resistant atrial fibrillation in patients with reduced left ventricular systolic function is limited. METHODS: Thirty-eight consecutive patients with paroxysmal or persistent atrial fibrillation (84.2% male), with median left ventricular ejection fraction of 37.3% were included in our study. All patients underwent the procedure with the 28-mm cryoballoon advance. RESULTS: There were no mayor complications related to the CB-A procedure. Median follow-up was 26.5 ±â€Š13.7 months. The freedom from atrial fibrillation after a blanking period of 3 months was 42.9% in our cohort of patients. During the follow-up period, 13 patients underwent at least a new electrophysiological procedure. After a single procedure, the univariate predictors of clinical recurrence after the blanking period were age and persistent atrial fibrillation. CONCLUSION: Second-generation CB-A of atrial fibrillation seems feasible and safe in patients with heart failure with reduced ejection fraction and heart failure with mid-range ejection fraction, in terms of complications rate and number of applications per vein. All pulmonary veins could be isolated with the 28-mm cryoballoon advance only.

Acute and one year outcome of premature ventricular contraction ablation guided by contact force and automated pacemapping software.

BACKGROUND: Radiofrequency (RF) ablation is a well-established approach to treat premature ventricular contractions (PVC) and is associated with good outcomes. AIM: The present study sought to analyze the acute efficacy and 1-year outcomes of PVC ablation using RF technology with an approach based on automated pace-mapping and contact force (CF) information. METHODS: Sixty-one consecutive patients (52.4% males, age 45.9 ± 12.5) underwent catheter ablation for symptomatic monomorphic PVC. All procedures were guided by a 3-dimensional mapping system; site of ablation was selected based on PASO™ aided pace-mapping; RF was started on the selected location when stable catheter position with >10 g of CF were obtained.The procedure was defined as acutely effective if the PVC was eliminated and it did not recur during within 30 minutes. Long-term efficacy was defined as a decrease by more than 95% at 1 year of the initial PVC burden at ECG Holter monitoring. RESULTS: The PVC ablation was performed in the right ventricular outflow tract in 37 patients (60.7%), left ventricle in 15 patients (24.6%), coronary cusps in 6 patients (9.8%), right ventricle in 3 patients (4.9%); PVC ablation was acutely successful in 59 of patients (96.7%). At 1-year efficacy was obtained in 57 patients (93.4%). No major complications occurred. Mean procedural and fluoroscopy time were 94.5 ± 20.9 and 4.3 ± 2.5 minutes respectively. CONCLUSION: Premature ventricular contraction RF ablation mainly guided by PASO™ and CF showed high success rate in both acute and 1-year follow-up (96.7% and 93.4% respectively). The best efficacy cut-off for RF ablation of PVCs has been identified in presence of both PASO™ ≥95% and CF >10 g.

Posterior box isolation as an adjunctive ablation strategy during repeat ablation with the second-generation cryoballoon for recurrence of persistent atrial fibrillation: 1-year follow-up.

BACKGROUND: The creation of a posterior box isolation of the left atrium (LAPWI) in addition to pulmonary vein isolation (PVI) with the second-generation cryoballoon (CB-A) seems to offer promising clinical outcome in patients affected by persistent atrial fibrillation (PersAF). AIM: This work aims to study the clinical outcome of an ablation strategy based on the creation of a LAPWI during repeat procedures for recurrent AF after an index CB-A procedure for PersAF. METHODS AND RESULTS: A total of 33 patients having undergone a repeat procedure consisting in redo PVI plus LAPWI for recurrent PersAF with the CB-A after an index PVI ablation were retrospective included in our study. Electrical reconnection could be documented in 18 veins (13%). The LAPW was successfully isolated solely by CB-A ablation in 30 out of 33 (91%) patients; in the remaining 3 patients, isolation of the LAPW was completed by focal tip-irrigated RF ablation. The mean number of CB-A applications required for the superior portion of the LAPW and the inferior portion of the LAPW creation were 5.4 ± 0.9 and 4 ± 0.6, respectively. After a mean follow-up of 11.8 ± 3 months, 28 patients (85%) did not experience recurrence of any atrial arrhythmias during follow-up, without the need of further ablation or class I or III AADs. CONCLUSION: Left posterior wall isolation with the CB-A is feasible and safe during repeat ablation procedures for recurrent PersAF. In our study, the 12-month freedom from any arrhythmia was 85% following this ablation strategy.

Evaluation of the luminal esophageal temperature behavior during left atrium posterior wall ablation by means of second-generation cryoballoon.

PURPOSE: The purpose of this study was to clarify the behavior of the luminal esophageal temperature (LET) in a cohort of patients undergoing second-generation cryoballoon (CB-A) for pulmonary vein isolation (PVI) and additional left atrium posterior wall (LAPW) ablation by means of CB-A. METHODS: Thirty patients with symptomatic persistent AF (PersAF), having undergone PVI + LAPW cryoballoon ablation with LET monitoring. RESULTS: Interruption of the application due to a LET below 15 °C occurred in 5 patients (16.6%), 2 at the LIPV and 3 in the LAPW. The 5 patients underwent gastroscopy the day after ablation. In all individuals, esophageal thermal lesion (ETL) was absent. CONCLUSION: The evaluation of LET might be an additional tool in helping to prevent damage to the esophagus during the LAPW ablation with the CB-A by stopping the freeze application when temperature reaches values of < 15 °C.

Impact of an additional right pulmonary vein on second-generation cryoballoon ablation for atrial fibrillation: a propensity matched score study.

PURPOSE: Cryoballoon (CB) technology in the context of anatomical pulmonary vein (PV) variants might hypothetically hamper successful PV isolation (PVI). Our aim was to assess the impact of a right middle PV (RMPV) in the setting of second-generation cryoballoon (CB advance-CB-A), on procedural parameters and on mid-term follow-up. METHODS: Consecutive patients with AF presenting RMPV (RMPV+) at the pre-procedural computed tomography who underwent PVI by CB-A were enrolled. Comparison with propensity score-matched patients without RMPV (RMPV-) was performed. Acute procedural parameters and clinical follow-up were assessed. RESULTS: A total of 240 patients (80 RMPV+) were included in the analysis. Twelve of 80 (15%) RMPV+ patients underwent a direct cryo-application in this variant and accomplished the isolation without phrenic nerve palsy, whereas in 25 of 80 (31%) RMPV+ patients, the RMPVs were not targeted directly nor indirectly (by co-occlusion during application at a major PV). At a median follow-up of 17.3 [interquartile range 11.3-26.5] months, there was no significant difference in AF-free survival between RMPV+ and RMPV- patients (78.8 vs 78.1%, P = 1.00), and the recurrence of atrial arrhythmias among patients with versus without an intentional or indirect cryo-application to the RMPV was not different (22 vs 20%, P = 1.00). CONCLUSIONS: Mid-term outcome after CB-A ablation did not differ between RMPV+ and RMPV- patients. Within RMPV+ patients, outcome was similar between those with versus without a cryo-application (either direct or indirect) to the additional vein.

Hybrid thoracoscopic epicardial ablation of right ventricular outflow tract in patients with Brugada syndrome.

BACKGROUND: Abnormal delayed electrograms (EGMs) from the anterior wall of the right ventricular outflow tract (RVOT) epicardium have become the ablation target in Brugada syndrome (BrS). OBJECTIVE: The aim of this study was to analyze the safety, feasibility, and efficacy of a novel hybrid thoracoscopic approach to perform epicardial RVOT radiofrequency ablation in BrS. METHODS: Thirty-six patients with BrS (26 men (72.2%); mean age 36.6±15.8 years; range 3-63 years) who underwent hybrid thoracoscopic epicardial ablation of RVOT from January 2016 to April 2018 were included in this study. Two expert electrophysiologists analyzed the EGMs during ajmaline challenge and guided the surgeon to perform ablation. Ajmaline challenge was repeated after 1 month to assess the absence of the BrS electrocardiographic pattern. Patients were followed by remote monitoring and outpatient visits every 6 months. RESULTS: The elimination of all abnormal EGMs was achieved in 94.4% of patients. After a mean follow-up of 16 ± 8 months (range 6-30 months), freedom from ventricular arrhythmias was obtained in 7 (77.8%) patients in secondary prevention 9/36 (25%) and in 24 (100%) patients in primary prevention 24/36 (75%). Major complications were observed in 1 patient (2.8%), who experienced late cardiac tamponade. CONCLUSION: Hybrid thoracoscopic epicardial RVOT ablation in BrS is a safe and feasible approach, allowing direct visualization of ablation during radiofrequency delivery. Because of ventricular arrhythmia recurrences, implantable cardioverter-defibrillator implantation is still mandatory in patients treated in secondary prevention and with high risk.

Real-Time Recordings in Cryoballoon Pulmonary Veins Isolation: Comparison Between the 25mm and the 20mm Achieve Catheters.

AIMS: Real Time Recordings (RTR) of pulmonary vein (PV) activity provide important information in the setting of the 2nd generation Cryoballoon (CB-A), as a funcion of time to isolation. Visualization of RTR with the standard inner lumen mapping catheter (ILMC) 20mm Achieve (AC) is possible in roughly 50% of PVs. A novel 25mm-Achieve Advance (AC-A) has been developed with the aim of increasing the detection of RTR. The purpose of this study is to compare the AC-A with the AC, to feasibility and improvement of RTR. METHODS: We assigned 50 patients with paroxysmal or persistent atrial fibrillation to CB-A PVI, using the AC-A as ILMC. We compared this group with 50 patients, matched for age and left atrial volume, who previously underwent the CB-A PVI using the AC. RESULTS: RTR were more frequently observed with the AC-A than with the AC (74% vs 49%; p= 0.02). RTR in the left superior PVs was similar in both groups (74% vs 72%, p= 0.8). RTR with the AC-A were equally appreciated in left or right sided, superior or inferior PVs. No significant differences were found in terms of feasibility, procedure fluoroscopy and freezing times, nadir temperatures, and acute PVI. CONCLUSIONS: CB-A PVI with the AC-A is feasible and safe in all PVs. The AC-A has proven significantly superior in visualising RTR if compared to the AC, affording RTR in 74% of PVs.

Single freeze per vein strategy with the second-generation cryoballoon for atrial fibrillation: a propensity score-matched study between 180- and 240-s application time in a large cohort of patients.

Aims: The single-freeze strategy using the second-generation cryoballoon (CB-A, Arctic Front Advance, Medtronic, Minneapolis, MN, USA) has been reported to be as effective as the recommended double-freeze approach in several single-centre studies. In this retrospective, international, multicentre study, we compare the 3-min single-freeze strategy with the 4-min single-freeze strategy. Methods and results: Four hundred and thirty-two patients having undergone pulmonary vein isolation (PVI) by means of CB-A using a single-freeze strategy were considered for this analysis. A cohort of patients who were treated with a 3-min strategy (Group 1) was compared with a propensity score-matched cohort of patients who underwent a 4-min strategy (Group 2). Pulmonary vein isolation was successfully achieved in all the veins using the 28-mm CB-A. The procedural and fluoroscopy times were lower in Group 1 (67.8 ± 17 vs. 73.8 ± 26.3, P < 0.05; 14.9 ± 7.8 vs. 24.2 ± 10.6 min, P < 0.05). The most frequent complication was PNP, with no difference between the two groups (P = 0.67). After a mean follow-up of 13 ± 8 months, taking into consideration a blanking period of 3 months, 85.6% of patients in Group 1 and 87% of patients in Group 2 were free from arrhythmia recurrence at final follow-up (P = 0.67). Conclusion: There is no difference in acute success, rate of complications, and freedom from atrial fibrillation recurrences during the follow-up between 3-min and 4-min per vein freeze strategies. The procedural and fluoroscopy times were significantly shorter in 3-min per vein strategy.