Feasibility of a novel atrial mechanical sensing method for leadless atrioventricular synchronous pacing.

INTRODUCTION: Few studies have demonstrated a high degree of atrioventricular (AV) synchrony with a new leadless pacemaker called Micra AV. Our group previously reported a new and unique sensing method. We believe that this novel sensing method, "Simplified A3 method," might facilitate better AV synchrony than a conventional sensing method in almost all cases with Micra AV implantation. METHODS: We conducted a non-randomized retrospective study comparing the two pacing methods at two centers. From December 1, 2021 to October 31, 2022, Micra AV was implanted for 32 patients at the two centers. Twenty of the 32 patients with sinus rhythm and complete AV block were included in this study. In Group 1, the conventional setting was programmed as follows: auto A3 threshold, auto A3 window-end (WE), and auto A4 threshold turned on during hospitalization. In Group 2, the "Simplified A3 method" was programmed as follows: auto A3 threshold and auto A3WE turned off. Instead, an intentionally prolonged A3WE (850-1000 ms) and low A3 threshold (A3 signal amplitude + 0.5-1.0 m/s2) were programmed. RESULTS: Twenty patients were analyzed. In Group 2, AV synchrony (%AMVp) was significantly higher at the first outpatient clinic (63.0 ± 5.7% vs 81.0 ± 4.2%, p = .03). A3 threshold was significantly lower in Group 2 (5.9 ± 0.7 m/s2, p < .05 vs 2.3 ± 0.5 m/s2, p < .05). CONCLUSION: Our novel sensing method might be a more feasible sensing method for obtaining higher AV synchrony than the conventional algorithm.

Second Micra leadless pacemaker implantation by using intracardiac echocardiography.

The strategy after battery depletion was not established in Micra leadless pacemaker system (Micra). There are still some concerns in the 2nd Micra implantation, such as the mechanical interaction between both devices. The position of the 2nd Micra should be placed apart from the 1st Micra. We present a case of 1st Micra battery depletion who successfully underwent the 2nd Micra implantation under the intracardiac echo guidance. In our case, intracardiac echo was a very effective tool for confirming the location of Micra implantation.

Predictors of durable electrical isolation in the setting of second-generation cryoballoon ablation: A comparison between left superior, left inferior, right superior, and right inferior pulmonary veins.

AIM: The aim of this study is to assess specific per-vein procedural predictors of pulmonary vein (PV) late reconnection in cryoballoon ablation (CbA) METHODS AND RESULTS: We enrolled 148 consecutive patients undergoing a redo procedure after a previous index CbA in our center. A reconnection in at least one PV was found in 80 patients (54.1%) and the most frequently reconnected PV was the right inferior pulmonary vein (RIPV). Overall, pulmonary vein reconnection (PVr) was associated with longer time to -40°C (Tt-40°C) (54.4 ± 21.7 vs 67.6 ± 27.6 seconds; P < .001), warmer nadir temperature (NT) (-49.7°C ± 5.4°C vs -46.5°C ± 5.8°C; P < .001) and temperature at 60 seconds (-41.8°C ± 4.5°C vs -39.8°C ± 4.2°C; P < .001). The performance of these predictors differed between the veins. In particular, a comparable behavior was observed for left superior pulmonary vein (LSPV) and right superior pulmonary vein (RSPV), where NT ≤ -48°C showed a sensibility and a specificity, respectively, of 62% and 65% and 71% and 72% in predicting durable PV isolation. For RIPV, NT ≤ -48°C showed a sensitivity of 74% but low specificity (53%). Tt -40°C less than 60 seconds showed good negative predictive values, respectively, 83.9% for LSPV, 94.9% for left inferior pulmonary vein (LIPV), 90.2% for RSPV, and 82.7% for RIPV. Previous predictors cannot be used for LIPV. CONCLUSIONS: Freezing behavior and reconnection rates differ significantly among the four PVs. Freezing temperature parameters strongly predict late PVr in superior PVs and are slightly different in RIPV but can be applied as well. LIPV freezing behavior is the most different. Its reconnection is uncommon even in the subset of worse freezing temperatures and specific CB predictors cannot be identified.

Pulmonary veins anatomical determinants of cooling kinetics during second-generation cryoballoon ablation.

AIM: The aim of the study was to investigate the role of anatomical characteristics of the pulmonary veins (PVs) determining cooling kinetics during second-generation cryoballoon ablation (CbA). METHODS AND RESULTS: we enrolled all consecutive patients who underwent CbA for symptomatic atrial fibrillation in our center from January 2019 to March 2019. All patients had complete computed tomography scans of the heart before the ablation. Anatomical characteristics were tested for prediction of a nadir temperature (NT) ≤ -48°C. Significant differences were noted among PV max diameter (20.8 ± 2.8 vs 18.5 ± 2.5 mm; P < .001); PV minimum diameter (15.2 ± 3.0 vs 13.0 ± 3.1 mm; P < .001); PV area (268.1 ± 71.9 vs 206.2 ± 58.7 mm2 ; P < .001); PV ovality (1.4 ± 0.3 vs 1.5 ± 0.3; P = .005); and PV trunk length (27.4 ± 7.4 vs 21.3 ± 6.5 mm; P < .001). A scoring system was created by assigning one point each ranging from 0 (best anatomical combination) to 5. In the group with a score of 0, 94.0% of the CbA could reach a NT ≤ -48°C whereas with a score of 5, only 29.0% (P < .001). Left superior pulmonary vein with short trunk length and acute angle of PV branch was significantly associated with warmer NT (11.8% satisfactory CbA; P = .003). Regarding right inferior pulmonary vein, trunk length (P = .004), maximum diameter (P = .044), and transverse angle (P = .008) were independently associated with good NT. CONCLUSION: Anatomical PV features are associated with cooling kinetics and an anatomical score could predict lower NT during second-generation CbA. Specific characteristics were identified for inferior PV. Although heart imaging is not mandatory prior CbA, it can be a useful tool to predict cooling kinetics.

A novel strategy to treat vaso-vagal syncope: Cardiac neuromodulation by cryoballoon pulmonary vein isolation.

BACKGROUND: Clinical management of vaso-vagal syncope (VVS) remains challenging since no therapy has proven to completely prevent VVS recurrence. OBJECTIVE: The purpose of this study was to analyze the mid-term outcome of cryoballoon (CB) cardioneuroablation achieved by pulmonary vein isolation (PVI) in patients with VVS. METHODS: Patients who underwent CB cardioneuroablation in our centers between January 2014 to June 2018 were included. All patients had a history of VVS or pre-syncope despite therapeutic attempts with medical and/or pacing treatments. Patients were excluded in case of structural heart diseases, cerebrovascular diseases or suspected drug-related syncope. Both heart rate (HR) and atrio-ventricular (AV) interval were analyzed on the 12-lead electrocardiogram (ECG) the day before the procedure, the day after, and in the follow-up. RESULTS: In total, 26 patients (76.9% males, 37.5 ± 9.0 years old) were included. All patients underwent a successful procedure with the 28 mm second-generation Arctic Front Advance CB. No major complication occurred. At a mean follow-up of 20.1 ± 11.6 months the freedom from VVS or reflex pre-syncope was 83,7%, with 22 patients free from any clinical recurrence. Basal HR significantly increased the day after the procedure (57.2 bpm vs 78.3 bpm, p < 0.001), while at the final follow-up it stabilized at a value halfway between the 2 previous ones (69.8 bpm, p = 0.0086). The AV interval didn't modify significantly after the procedure. CONCLUSION: Endocardial autonomic denervation achieved by CB PVI appears to be an effective and safe treatment option for patients with refractory VVS and reflex pre-syncope.

Anatomic predictors of late right inferior pulmonary vein reconnection in the setting of second-generation cryoballoon ablation.

INTRODUCTION: The right inferior pulmonary vein (RIPV) accounts as the most frequently reconnected vein after pulmonary vein isolation using second-generation cryoballoon ablation (CB-A). Our objective was to assess anatomic predictors of late RIPV reconnection based on preprocedural computed tomography scan. METHODS: Patients with a repeat procedure for atrial tachyarrhythmia recurrence after index CB-A procedure were included. A total of 129 RIPVs were evaluated for ostial diameters, ostial area, and branching pattern. Interior angle between RIPV and horizontal line in the frontal/transversal plane was used to measure the RIPV orientation: RIPV frontal/transversal angle, respectively. In addition, interior angle between RIPV and the line perpendicular on the septal intersection line at the level of the fossa ovalis, estimated as trans-septal (TS) puncture site, was measured in the frontal/transversal view: RIPV-TS frontal/transversal angle, respectively. RESULTS: Late vein reconnection was present in 36/129 RIPVs (28%). Warmer balloon nadir temperature (P = .01), more inferior (P < .001) and posterior (P < .01) RIPV orientation (ie, more positive RIPV frontal and RIPV transversal angle, respectively), and sharper RIPV-TS frontal angle (P < .001) were associated with late RIPV reconnection on univariate analysis. Independent variables after multivariate analysis were nadir temperature (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.03-1.23; P = .013) and RIPV frontal angle (OR, 1.13, CI, 1.07-1.19; P < .001). CONCLUSION: Frontal RIPV orientation could significantly predict late RIPV electrical reconnection after CB-A. Therefore, preprocedural anatomic assessment of the RIPV might be useful to plan the correct ablation strategy.

Radiofrequency versus cryoballoon ablation for atrial fibrillation in the setting of left common pulmonary veins.

BACKGROUND: A left common pulmonary vein (LCPV) accounts as the most frequent pulmonary vein (PV) variation. Our aim was to compare the performance of radiofrequency (RF) versus second-generation cryoballoon (CB-A) ablation in patients with atrial fibrillation (AF) and LCPVs. METHODS: In a total cohort of 716 patients undergoing PV isolation with preprocedural CT-scanning, LCPV+ patients were selected with measurement of PV ostial area and trunk distance. All LCPV+ patients were matched between RF and CB-A group in a 1:1 ratio based on propensity scores, and compared for outcome. RESULTS: Left common pulmonary veins were found in 31% (88/283) RF versus 34% (146/433) CB-A patients, respectively, (P = .44). In the matched population of 83 LCPV+ patients in each group, electrical isolation could be achieved in all left-sided PVs. No significant difference was noted for the rate of AF/left atrial tachyarrhythmia (LAT) recurrence between RF and CB-A group (30% vs 28%, P = .86), with similar AF/LAT-free survival (log rank, P = .71). There were 48 patients with AF/LAT recurrence (29%) during the follow-up. Recurrence rate between paroxysmal versus persistent AF was 27/120 (22.5%) versus 21/46 (46%), P = .004. Cox proportional regression analysis withheld LA volume and persistent AF as independent variables to predict AF/LAT recurrence. No increased hazard for AF/LAT recurrence was observed for patients with a long (>15 mm) vs short (5-15 mm) LCPV trunk (OR 1.14, 95% CI 0.6-2.2, P = .7). CONCLUSIONS: In our study, equal efficacy and outcome was noted in LCPV+ patients between RF and CB-A technology.

A case of short-coupled variant of Torsade de Pointes with bystander early repolarization in inferior leads.

The presence of J waves in cases of ventricular fibrillation (VF) is known to be a risk for sudden cardiac death. Recently, the effectiveness of radiofrequency catheter ablation (RFCA) for early repolarization syndrome (ERS) has been reported.The patient is a 30-year-old male with elevated J waves of 0.1 mV in the inferior leads, who had previously developed VF and undergone implantable cardioverter defibrillator (ICD) implantation. Because the VF from short coupled premature ventricular contraction (PVC) was presented, the RFCA of the triggered PVC was attempted. But it was unsuccessful due to no inducibility of the triggered PVC. After that, despite anti-arrythmia drug treatment, appropriate ICD shock for VF was observed. Although we decided to do a second ablation and evaluated epicardial arrhythmia substrate, no specific findings of early repolarization syndrome were found in the electrophysiological study. Finally, we considered that the cause of VF was short-coupled variant of Torsade de Pointes, and PVC ablation was performed. VF has not occurred since. We consider that this is a rare case to evaluate the epicardial arrhythmogenic substrate of J wave. Learning objective: Ablation of the epicardial arrhythmogenic substrate in patients with early repolarization syndrome (ERS) has been shown to be effective, but the relationship between abnormal epicardial potentials and the pathophysiology is unclear. In this case, J-wave and epicardial delayed potentials were not considered to represent obvious arrhythmogenic substrates. Ablation of the triggered premature ventricular contraction may be effective in ERS without apparent abnormal potentials.

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.

Pulmonary Vein Remodeling Between Atrial Fibrillation Subtypes: A Matched Comparison Cardiac Computed Tomography-Based Study Between Patients With Paroxysmal and Persistent Atrial Fibrillation.

Although pulmonary vein (PV) isolation (PVI) is the cornerstone for atrial fibrillation (AF) ablation, no data exist comparing PV anatomy between AF subtypes directly. We aimed to compare PV anatomic characteristics between paroxysmal (PAF) and persistent AF (PeAF) in a matched population using cardiac computed tomography (CCT). Fifty-eight PeAF patients (with CCT prior first AF ablation procedure, absence of valvular disease/previous cardiac intervention), and 58 age-, sex-, body surface area-matched PAF patients were evaluated for left atrial (LA) and PV anatomy: ostial area, ovality index (OVI), transverse/frontal angles. In PeAF vs PAF group, beside higher LA volume index (LAVI), PVs' ostial areas were significantly larger (between 64 - 101 mm2, P < 0.001 for all PVs; remaining valid after LAVI adjustment for left superior [LS], left inferior [LI], and right inferior [RI]PV); left PVs were less oval (0.7 - 0.11 OVI decrease, P =0.039 for LSPV; P = 0.012 for LIPV); LSPV (P = 0.019), LIPV (P < 0.001), RIPV (P = 0.029) were more posteriorly directed; whereas LSPV (P = 0.002), and right superior PV (P = 0.043) were more superiorly directed. Incidence of anatomic variations or early branching was not different. This study showed significant anatomical PV differences between patients with PeAF and PAF, in terms of PV orientation, ostial size and ovality. Anticipating such anatomical differences may aid in choosing the adequate catheter design and technology for PeAF ablation.

High parasympathetic activity as reflected by deceleration capacity predicts atrial fibrillation recurrence after repeated catheter ablation procedure.

PURPOSE: High parasympathetic nervous system (PNS) activity is accurately reflected by deceleration capacity (DC) and is involved in atrial fibrillation (AF) recurrence after catheter ablation procedure. When compared with initial catheter ablation procedure, repeated procedures for AF recurrence are followed by a lower success rates, estimated at 50%. Our objective was to evaluate the impact of PNS activity assessed by DC measured before repeated procedure on AF recurrence after repeated procedure. METHODS: Consecutive patients who underwent an initial catheter ablation procedure for pulmonary vein (PV) isolation and a repeated catheter ablation procedure for AF recurrence were selected. Additional 24-h ambulatory electrocardiographic recording between procedures for DC measurement was required for inclusion. A total of 110 patients were included. Seventy-two patients underwent cryoballoon (CB) ablation and 38 patients underwent radiofrequency (RF) ablation as initial procedure, while all patients underwent RF ablation as repeated procedure. RESULTS: DC was higher in cases with right-sided PV reconnection (p = 0.04, OR = 1.38, 95% CI = 1.08-1.78). In patients with CB ablation as initial procedure, DC was higher in patients with PV reconnection (p = 0.03, OR = 1.29, 95% CI = 1.11-1.70), and the number of reconnected PVs was higher in patients with DC ≥ 7.0 ms (median DC value used for dichotomization, p = 0.02, OR = 2.19, 95% CI = 1.10-4.37). In multivariate Cox regression, DC predicted AF recurrence after repeated ablation (p = 0.004, HR = 1.68, 95% CI = 1.35-1.82). In multivariate binary regression, DC predicted persistent AF type recurrence after repeated ablation (p = 0.01, OR = 1.50, 95% CI = 1.10-2.02). CONCLUSIONS: DC is a novel predictor of AF recurrence and AF recurrence type after repeated catheter ablation procedure. DC may reflect the need of more intensive treatment strategies in patients with high PNS activity.

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.

Electrophysiological findings in patients with isolated veins after cryoablation for paroxysmal atrial fibrillation.

AIMS: The main cause of atrial fibrillation recurrence after catheter ablation is pulmonary vein reconnection. The purpose of this retrospective study was to analyse the electophysiological findings in patients undergoing repeat procedures after an index cryoballoon ablation (CB-A) and presenting with permanency of pulmonary vein isolation (PVI) in all veins. In addition, we sought to compare the latter with a similar group of patients with reconnected veins at the redo procedure. METHODS: A total of 132 patients (81 men, 60.7 ±â€Š12.4 years) who underwent CB-A for paroxysmal atrial fibrillation (PAF) were enrolled. Indication for the redo procedure was symptomatic PAF in 83 (63%), persistent atrial fibrillation (PerAF) in 32 (24%) or persistent regular atrial tachycardia (RAT) in 17 (13%) patients. RESULTS: Seventy-five (57%) patients presented a pulmonary vein reconnection (pulmonary vein group) during the redo procedure, whereas 57 (43%) had no pulmonary vein reconnection (non-pulmonary vein group). The non-pulmonary vein group exhibited significantly more non-pulmonary vein foci and atrial flutters than the pulmonary vein group after induction protocol (51 vs. 24%, P = 0.002 and 67 vs. 36%, P = 0.003, respectively). Twenty-two (29.3%) patients of the pulmonary vein group and 20 (35%) patients of the non-pulmonary vein group had atrial fibrillation/RAT recurrence after a mean follow-up of 12.5 ±â€Š8 months. The survival analysis demonstrated no statistical significance in recurrence between both groups (log rank P = 0.358). CONCLUSION: Atrial fibrillation/RAT recurrence in patients after CB-A with durable PVI is significantly associated with non-pulmonary vein foci and atrial flutters. No statistically different success rate regarding atrial fibrillation/RAT freedom was detected between the pulmonary vein and non-pulmonary vein groups after redoing RF-CA.

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.

Correction to: Two-year follow-up of one-stage left unilateral thoracoscopic epicardial and transcatheter endocardial ablation for persistent and long-standing persistent atrial fibrillation.

Owing to a type error during final correction and proof data submission to the journal, there were mistakes introduced into the legends of Fig. 3 and Fig. 4 as well as into the Y-axis title of the plot of Fig. 4.

Two-year follow-up of one-stage left unilateral thoracoscopic epicardial and transcatheter endocardial ablation for persistent and long-standing persistent atrial fibrillation.

PURPOSE: The purpose of this study was to analyze the efficacy and complication rates of a one-stage left unilateral thoracoscopic hybrid procedure in a series of patients with persistent and long-standing persistent atrial fibrillation (AF) in a 2-year follow-up. METHODS: Fifty-one consecutive patients (34 males, 65.7 ± 8 years) having undergone hybrid isolation of pulmonary veins (PVs) and posterior wall of left atrium (LA) by means of left unilateral hybrid thoracoscopic ablation for symptomatic persistent (n = 22, 43%) and long-standing persistent atrial fibrillation (AF) (n = 29, 57%) were analyzed. RESULTS: At a mean follow-up of 24.9 ± 11.8 months (median 24), the success rate without antiarrhythmic therapy was achieved in 68.6% of patients. Procedure-related major complications were observed in 2 patients (4%) including diaphragmatic perforation and late pericardial tamponade requiring mini left-sided thoracotomy and pericardial drainage, respectively. The success rate did not significantly differ between persistent and long-standing persistent AF (respectively, 68.2 and 69%; P = 0.89). Patients with AF relapse during the blanking period were 3.8 times more likely to have AF recurrence after 3 months from the ablation procedure. CONCLUSION: The hybrid one-stage left unilateral thoracoscopic procedure exhibits encouraging results in the setting of both persistent and long-standing persistent AF after a 2-year follow-up, at a low rate of adverse events.

Ajmaline Testing and the Brugada Syndrome.

Brugada syndrome (BrS) diagnosis requires the presence of a typical type 1 ECG pattern. Owing to the spontaneous ECG variability, the real BrS prevalence in the general population remains unclear. The aim of the present study was to evaluate the prevalence of positive ajmaline challenge for BrS in a cohort of consecutive patients who underwent electrophysiological evaluation for different clinical reasons. All consecutive patients from 2008 to 2019 who underwent ajmaline testing were prospectively included. A total of 2,456 patients underwent ajmaline testing, 742 (30.2%) in the context of familial screening for BrS. In non-familial screening group (1,714) ajmaline testing resulted positive in 186 (10.9%). Indications for ajmaline testing were: suspicious BrS ECG in 23 cases (12.4%), palpitations in 27 (14.5%), syncope in 71 (38.2%), presyncope in 7 (3.8%), family history of sudden cardiac death in 18 (9.7%), documented ventricular arrhythmias in 12 (6.5%), unexplained cardiac arrest in 4 (2.2%), atrial fibrillation in 16 (8.5%), brady-arrhythmias in 1 (0.5%), and cerebrovascular accidents in 7 (3.7%). Compared with the overall population, ajmaline testing positive patients were younger (42.8 ± 15.5 vs 48.9 ± 20.4; p <0.001) and more frequently male (65.1% vs 56.3%; p = 0.023). Implantable cardioverter defibrillator was implanted in 84 patients (45.2%). During a median follow-up of 42.4 months, 12 appropriate shocks and 13 implantable cardioverter defibrillator related complications were reported. In conclusion, the BrS was diagnosed in an unexpected high proportion of patients that underwent ajmaline testing for a variety of cardiovascular symptoms. This can lead to an adequate counseling and clinical management in BrS patients.

Predictors of cardiac neuromodulation achieved by cryoballoon ablation performed in patients with atrial fibrillation who were in sinus rhythm before the ablation.

BACKGROUND: The impact of pulmonary vein isolation (PVI) performed with cryoballoon (CB) on the intrinsic cardiac autonomic nervous system (ICANS) remains unclear. OBJECTIVE: The purpose of this study was to evaluate the predictors and the clinical meaning of cardiac neuromodulation achieved by CB-ablation as assessed by sinus heart rate (HR) response after the procedure. METHODS: Patients who underwent CB-ablation for drug-resistant atrial fibrillation (AF) from January 2014 to October 2018 were included. Twelve­leads rest ECG was taken both before and after the procedure. After discharge, patients were scheduled for follow-up visits at 1, 3, 6, and 12 months and 24 h Holter recordings were obtained at each follow-up visit. All documented AF episodes of >30 s were considered as recurrence. RESULTS: Four-hundred seventy-two patients (62.3% male, age 56.7 ± 13.6 years, 97.2% paroxysmal AF) were included. Mean HR before the procedure was 60.17 ± 10.4 bpm, while the morning after the procedure mean HR was 75.48 ± 12.0 bpm. Age at enrollment (R = -0.26; p < 0.001), baseline HR before the CB-A (R = -0.32; p < 0.001), nadir temperature in each right pulmonary vein (R = -0.11, p = 0.022; R = -0.16; p = 0.001) were significantly associated with the ∆HR. At 2-year follow-up, freedom from recurrences was 83.1% for the patients with HR increase ≥15 bpm after CB-A and 66.3% in patients with HR increase ˂15 bpm (p = 0.021). CONCLUSION: Sinus HR increase is a frequent phenomenon after CB-A, that can be predicted by both clinical and procedural factors and that correlates with better outcome after cryo-PVI.

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.

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.