Atrial fibrillation-related stroke in women: Evidence and inequalities in epidemiology, mechanisms, clinical presentation, and management.

BACKGROUND: Atrial fibrillation (AF) is the most common clinical arrhythmia and one of the major causes of stroke, heart failure, sudden death, and cardiovascular morbidity. Despite substantial advances in (interventional) rhythm control treatment during the last decade, anticoagulation for stroke prevention remains a major component of AF treatment. HYPOTHESIS: There are important sex-specific differences in AF-related stroke, resulting from sex-specific mechanisms and therapeutic differences. METHODS: This review summarizes available data on sex differences in risk assessment and prevention of stroke and highlights current knowledge gaps in AF-related stroke mechanisms, prevention and management that warrant further research. RESULTS: Increased thrombotic risk in women is multifactorial, involving hormonal changes after menopause, structural, endocrine and lifestyle/social factors and their interactions. It is clear from randomized studies that women benefit from anticoagulant treatment and that their bleeding risk is similar to men. Women should therefore receive equivalent treatment to men, based on the validated criteria for anticoagulation therapy. However, women are not represented equally in the large randomized studies and sex-related information in many fields is lacking. CONCLUSIONS: Female sex is an established risk factor for stroke in AF patients. The evidence for sex-specific differences in stroke risk assessment and stroke prevention is accumulating. However, the underlying biological mechanisms remain incompletely understood and further studies are required in order to decrease AF-related morbidity and mortality.

Localization Of Accessory Pathways In Wolff Parkinson White Syndrome Using R/S Ratios On Surface Ecgs.

BACKGROUND: This study was conducted to establish the accuracy of R/S ratios in localizing accessory pathways in Wolff Parkinson White Syndrome on surface ECGs. METHODS: This was a retrospective cross-sectional study from January 2002 till December 2016 conducted at National Institute of Cardiovascular diseases in Karachi, Pakistan. The sample included 157 patients with manifesting Wolff Parkinson White (WPW) Syndrome on a 12-lead surface ECG. As per the inclusion criteria, patients who had persistent or intermittent pre-excitation on surface ECG and had undergone electrophysiological study (EP) were included in the sample. Individuals with both successful and unsuccessful ablation procedures were included. RESULTS: The sample consisted of 62.4% males (n=98) and 37.6% females (n=59) with mean age being 35.36±12.44. Accessory pathways (APs) were identified on the left side in majority of the patients with 54.1% (n=85) while right sided pathways were seen in 42.1% (n=66). Moreover, the most common accessory pathway amongst the males was Left Anterior (LA) and Left Lateral (LL) with a percentage of 48%, followed by Right Posteroseptal (RPS) at 20.4%. As opposed to this, the most common pathways amongst the females turned out to be RPS at 33.9% followed by LL and LA at 32.2%. Furthermore, the test using ratios were most effective in identifying left sided APs with sensitivity 74.1% and was least sensitive in identifying right sided pathways (sensitivity=40.7%). However, it was highly specific in locating right sided pathways with specificity of 94.6% as opposed to 83.3% in the left side. Furthermore, mid-septum regions had a sensitivity and specificity of 66.7% and 69.6% respectively. CONCLUSIONS: This establishes the effectiveness of R/S ratios in determining the location of accessory pathway based on the surface ECG prior to the ablation procedure. Since the younger population is affected more commonly, prolonged exposure to ionizing radiation can cause long term complications therefore, by this means, the duration of exposure can be reduced.

Cardiac electrophysiologic procedures - A ten years' experience at National Institute of Cardiovascular Diseases, Karachi.

OBJECTIVE: To review 10 years of clinical practice of cardiac electrophysiology study and radiofrequency catheter ablation in the treatment of supraventricular tachycardia. METHODS: The retrospective chart review was conducted at the National Institute of Cardiovascular Diseases, Karachi, and comprised records of all patients who underwent electrophysiological study and / or radiofrequency catheter ablation from January2007 to December 2016. SPSS 21 was used for data analysis. RESULTS: Of the 627 patients, 335(53.4%) were females. The overall mean age was 40.99}13.59 years. The major indication for procedure was supraventricular tachycardia 376(59.97%). Final electrophysiological study diagnosis was typical slow fast atrioventricular nodal re-entrant tachycardia in 303(48.3%) patients. The overall success rate was 472(75.3%). Procedure-related complications were reported in 25(4%) patients, and there was 1(0.15%) mortality. CONCLUSIONS: Cardiac electrophysiology studies and radiofrequency catheter ablation were found to be an effective and safe method for diagnosis and treatment of supraventricular tachycardia.

Implantable cardioverter defibrillator therapy in young individuals: comparison of conventional and subcostal approaches-a single-centre experience.

AIM: The aim of our study is to compare two approaches of implantable cardiac defibrillator (ICD) implantation, conventional (supra/subpectoral) and subcostal in young adults in terms of procedural complications and adverse events encountered during follow-up. METHODS AND RESULTS: From January 2007 to December 2013, all patients under the age of 50 years who received an ICD in our centre were included in this study. Patient's hospital records were analysed for procedural complications and adverse events during follow-up until December 2014. Data from device on first interrogation after implantation and on follow-up were also noted. A total of 106 patients of which 40.6% had Brugada's syndrome (65.1% male, age 33.6 ± 10.97 years) were included in analysis; 71 (61%) had ICD placed in (sub/supra) pectoral and 35 (33%) in subcostal position. Only seven patients received an epicardial lead system. During the follow-up period of 2.1 ± 1.8 years, 84.90% of the patients had no adverse events. Most of the complications, procedural and during follow-up, occur in conventionally placed, pectoral ICD. Lead follow-up data in both groups, conventional and subcostal, showed no difference in right ventricular (RV) shock impedance and R wave sensing, P-value = 0.56 and 0.77, respectively. Lead survival was 95 and 97%, respectively, in conventional and subcostal groups over a mean follow-up of 2.1 ± 1.8 years. Log-rank test for lead survival was not significant in terms of site of implantation. CONCLUSION: To the best our knowledge, this is the first study demonstrating subcostal ICD placement in young adults and resulting in equivalent to better outcomes when compared with conventionally placed pectoral ICD. Subcostal ICD placement might be considered an alternative option in young adults as it results in better procedural outcomes and also comparable rate of adverse events during follow-up, but bigger studies with a larger number of patients are needed for a definitive conclusion.

Prevalence and Clinical Impact of Early Repolarization Pattern and QRS-Fragmentation in High-Risk Patients With Brugada Syndrome.

BACKGROUND: The phenotypic heterogeneity of Brugada syndrome (BrS) can lead some patients to show an additional inferolateral early repolarization pattern (ERP), or fragmented QRS (f-QRS). The aim of the study was to investigate the prevalence and clinical impact of f-QRS, ERP or combined f-QRS/ERP in high-risk patients with BrS. METHODS AND RESULTS: Patients with spontaneous or drug-induced BrS and an indication to receive an implantable cardioverter-defibrillator (ICD) were considered eligible for this study. From 1992 to 2012, a total of 176 consecutive patients with BrS underwent ICD implantation. Among them, 48 subjects (27.3%) presented with additional depolarization and/or repolarization abnormalities. f-QRS was found in 29 (16.5%), ERP in 15 (8.5%), and combined f-QRS/ERP in 4 patients (2.3%). After a mean follow-up of 95.2±51.9 months, spontaneous sustained ventricular arrhythmias were documented in 8 patients (16.7%). No significant difference was found in the rate of appropriate shocks between patients presenting with f-QRS or ERP and those without abnormalities. Patients with both f-QRS and ERP had a significantly higher rate of appropriate shocks (HR: 4.1; 95% CI: 1.1-19.7; P=0.04). CONCLUSIONS: Fragmented QRS and ERP are common ECG findings in high-risk BrS patients, occurring in up to 27% of cases. When combined, f-QRS and ERP confer a higher risk of appropriate ICD interventions during a very long-term follow-up. (Circ J 2016; 80: 2109-2116).

Single 3-Minute versus Double 4-Minute Freeze Strategy for Second-Generation Cryoballoon Ablation: A Single-Center Experience.

INTRODUCTION: Second-generation cryoballoon (CB-Adv) ablation is highly effective in achieving pulmonary vein isolation (PVI) with promising mid-term clinical outcome. However, the ideal freezing strategy is still under debate. The aim of this study was to assess the efficacy of a single 3-minute approach compared to the conventional 4-minute plus bonus application using CB-Adv. METHODS AND RESULTS: One hundred and sixty patients (67% male; mean age 58.0 ± 13.3 years) underwent PVI using CB-Adv for paroxysmal atrial fibrillation (PAF). Among 160 patients, 80 received a single 3-minute approach (3-mns group), while the remaining 80 conventional 4-minute plus bonus-freeze (4-mns group). Mean procedure and fluoroscopy times were 90.6 ± 15.8 and 18.3 ± 6.9 in the 4-mns group, 75.2 ± 17.1 and 13.5 ± 8.7 in the 3-mns group (P < 0.001, respectively). First-freeze isolation rate was 91.6% in the 4- versus 90.6% in the 3-mns group (P = 0.78). Persistent phrenic nerve palsy (PNP) occurred in 6/80 (3.5%) in the 4-mns group and 4/80 in the 3-mns group (P = 0.75). The overall freedom from ATas 2 years after the procedure was 78.1% (125/160): 77.5% (62/80 patients) in the 3-mns and 78.8% (63/80 patients) in the 4-mns group (P = 0.82). In multivariate analysis, time to PVI and nadir temperature independently predicted ATa recurrences (P < 0.001). CONCLUSIONS: CB-Adv ablation for PAF is highly effective, resulting in 78% 2-year freedom from arrhythmic recurrences. A "single 3-minute strategy" showed equal efficacy as compared to the conventional 4-minute plus bonus freeze approach at 2-year follow-up, providing shorter procedure and fluoroscopy time. Nadir temperature and time to PVI were predictors of arrhythmic recurrences. "Bonus-freeze" strategy might be unnecessary.

Clinical characterisation and long-term prognosis of women with Brugada syndrome.

OBJECTIVES: Brugada syndrome (BS) in women is considered an infrequent condition with a more favourable prognosis than in men. Nevertheless, arrhythmic events and sudden cardiac death (SCD) also occur in this population. Long-term follow-up data of this group are sparse. The purpose of the present study was to investigate the clinical characteristics and long-term prognosis of women with BS. METHODS: A consecutive cohort of 228 women presenting with spontaneous or drug-induced Brugada type I ECG at our institution were included and compared with 314 men with the same diagnosis. RESULTS: Mean age was 41.5±17.3 years. Clinical presentation was SCD in 6 (2.6%), syncope in 51 (22.4%) and the remaining 171 (75.0%) were asymptomatic. As compared with men, spontaneous type I ECG was less common (7.9% vs 23.2%, p<0.01) and less ventricular arrhythmias were induced during programmed electrical stimulation (5.5% vs 22.3%, p<0.01). An implantable cardioverter defibrillator (ICD) was implanted in 64 women (28.1%). During a mean follow-up of 73.2±56.2 months, seven patients developed arrhythmic events, constituting an event rate of 0.7% per year (as compared with 1.9% per year in men, p=0.02). Presentation as SCD or sinus node dysfunction (SND) was risk factor significantly associated with arrhythmic events (hazard risk (HR) 25.4 and 9.1). CONCLUSION: BS is common in women, representing 42% of patients in our database. Clinical presentation is less severe than men, with more asymptomatic status and less spontaneous type I ECG and prognosis is more favourable, with an event rate of 0.7% year. However, women with SCD or previous SND are at higher risk of arrhythmic events.

Fluoroscopic position of the second-generation cryoballoon during ablation in the right superior pulmonary vein as a predictor of phrenic nerve injury.

AIMS: Phrenic nerve injury (PNI) is the most frequently observed complication during pulmonary vein isolation procedure using the second-generation cryoballoon (CB). Our objective was to analyse the correlation between the fluoroscopic position of the 28 mm CB during ablation in the right superior pulmonary vein (RSPV) and the occurrence of PNI. METHODS AND RESULTS: A total of 165 patients having undergone the large 28 mm CB ablation were retrospectively reviewed. Positioning of the CB relative to the cardiac silhouette was classified under fluoroscopic guidance in antero-posterior projection during RSPV ablation. Regarding the lower half of the balloon, CB positioning was defined as follows: (A) completely inside the cardiac shadow; (B1) <1/3 outside the cardiac shadow; and (B2) ≥1/3 outside the cardiac shadow. Phrenic nerve injury occurred in 9.7% (16/165) during ablation in the RSPV. The occurrence of PNI was 0.9, 10.6, and 90.1% in positions A, B1, and B2, respectively (A vs. B1, P = 0.01; B1 vs. B2, P < 0.0001). Among other pre-procedural and procedural variables, the B2 position was the strongest independent determinant for predicting PNI at RSPV (P = 0.001, odds ratio: 119.9; 95% confidence interval: 11.6-1234.7) after multivariable analysis. CONCLUSION: The incidence of PNI at the RSPV significantly increased in case of more distal positioning of the CB relative to the cardiac shadow. This simple and straightforward intra-procedural indicator might prone the operators to attempt occluding the RPSV more proximally in order to avoid PNI.

Repeat Procedures After Hybrid Thoracoscopic Ablation in the Setting of Longstanding Persistent Atrial Fibrillation: Electrophysiological Findings and 2-Year Clinical Outcome.

INTRODUCTION: In order to increase success rates of invasive treatment of persistent atrial fibrillation, the hybrid approach was developed, combining video-assisted thoracoscopic epicardial procedure with conventional endocardial catheter ablation. Currently, there are no reports of electrophysiological findings and clinical outcomes of repeat procedures after the hybrid approach. METHODS AND RESULTS: Out of 64 patients who were treated by hybrid ablation for persistent atrial fibrillation (AF), 14 underwent the repeat catheter ablation and were selected for this study. All 14 patients initially presented with longstanding persistent atrial fibrillation and markedly dilated atria. The hybrid procedure was performed in a single act and the mean time to redo procedure was 346 ± 227 days. In 57% of patients indication for redo procedure was regular atrial tachycardia, and the rest presented with recurrent atrial fibrillation. In 36% of patients, recovered conduction was found along the previous ablation lesions. Only 9% of pulmonary veins were reconnected (0.36 veins per patient) and 7% of box lesions were not complete. The overall success rate at 2 years follow-up after the repeat procedure, including second repeat procedure and patients taking antiarrhythmic drugs, was 64% (57% without drugs and further ablation). One case of moderate pulmonary vein stenosis was detected as a consequence of hybrid procedure. CONCLUSION: Hybrid atrial fibrillation ablation results in durable lesions and high rates of chronic pulmonary vein isolation even after long-term follow-up. Most of the repeat procedures after the hybrid approach are related to left atrial flutters that could be successfully treated by catheter ablation.

One-year follow-up after second-generation cryoballoon ablation for atrial fibrillation in a large cohort of patients: a single-centre experience.

AIM: The second-generation cryoballoon (CB-Adv) is effective in achieving pulmonary vein isolation (PVI) with encouraging results. In this study, we assessed the single-procedure outcome on a 1-year follow-up period in a large sample of patients having undergone PVI for drug-resistant atrial fibrillation (AF) using the CB-Adv. METHODS AND RESULTS: A total of 393 patients (122 female, 31%; mean age 57.7 ± 12.9 years) with drug-refractory AF undergoing PVI using the novel CB-Adv were enrolled. Follow-up was based on outpatient clinic visits including Holter electrocardiograms. Recurrence of atrial tachyarrhythmias (ATas) was defined as a symptomatic or documented episode >30 s. A total of 1572 pulmonary veins (PVs) were identified and successfully isolated with 1.2 ± 0.3 mean freezes. Mean procedure and fluoroscopy times were 87.1 ± 38.2 and 14.9 ± 6.1 min, respectively. At a mean follow-up of 12 months, freedom from ATas after a single procedure was achieved in 85.8% of patients with paroxysmal atrial fibrillation and in 61.3% of patients with persistent AF (persAF). Similar success rates were observed between bonus freeze and single freeze strategies, 82.5 and 81.8%, respectively (P = 0.9). Multivariate analysis demonstrated that persAF (P = 0.04) and relapses during blanking period (BP) (P < 0.0001) were independent predictors of ATas recurrences. CONCLUSION: Freedom from any ATa can be achieved in 81.9% of patients after a single CB-Adv procedure in a large cohort of patients. A bonus freeze does not influence the clinical outcome, and reducing the duration of the cryoapplication to 3 min offers excellent results. Persistent AF and arrhythmia recurrence during the BP are strong predictors of AF recurrence.

Phrenic nerve injury during ablation with the second-generation cryoballoon: analysis of the temperature drop behaviour in a large cohort of patients.

AIMS: The present study sought to analyse the relationship between the temperature drop during the cryoenergy application and the occurrence of phrenic nerve injury (PNI) in a large cohort of patients having undergone second-generation cryoballoon ablation (CB-A). METHODS AND RESULTS: The first 550 consecutive patients having undergone CB-A for atrial fibrillation were enrolled. Attained temperatures at 20, 30, 40, and 60 s during cryoablation in the right-sided pulmonary veins (PVs) were collected. Diagnosis of PNI was made if reduced motility or paralysis of the hemidiaphragm was detected. The incidence of PNI in the study population was 7.3% (40/550); among them, only four (0.7%) did not resolve until discharge and one (0.2%) still persisted at 23 months. Patients with PNI exhibited significantly lower temperatures at 20, 30, and 40 s after the beginning of the cryoapplication in the right superior PV (RSPV) (P = 0.006, P = 0.003, and P = 0.003, respectively). The temperature drop expressed as Δ temperature/Δ time was also significantly higher in patients with PNI. Low temperature during the early phases of the freezing cycle (less than -38°C at 40 s) predicted PNI with a sensitivity of 80.5%, a specificity of 77%, and a negative predictive value of 97.9%. Among patients with a fast temperature drop during RSPV ablation, an RSPV diameter >23.55 × 17.95 mm significantly predicted PNI occurrence. CONCLUSION: The analysis of the temperature course within the first 40 s after the initiation of the freezing cycle showed that the temperature dropped significantly faster in patients with PNI during ablation in the RSPV.

Electrophysiological findings following pulmonary vein isolation using radiofrequency catheter guided by contact-force and second-generation cryoballoon: lessons from repeat ablation procedures.

AIMS: To assess the incidence of late pulmonary vein (PV) reconnection following index PV isolation (PVI) procedure initially achieved with radiofrequency contact-force catheter ablation (CFCA) and second-generation cryoballoon ablation (CB-AdvA). METHODS AND RESULTS: A total of 56 consecutive patients (41 male, 73.2%; mean age 60.8 ± 11.8 years) underwent a repeat ablation because of recurrent atrial tachyarrhythmias (ATas) after index PVI achieved with CFCA (30 patients) or CB-AdvA (26 patients). All repeat procedures were performed by the means of CFCA. In the CFCA group, among 119 PVs, 43 (36.1%) showed conduction gaps in 24 patients (1.8 per patient), whereas in the CB-AdvA group among 103 veins, 21 (20.4%) showed a PV reconnection in 18 patients (1.2 per patient) (P = 0.01). The left superior pulmonary vein was less frequently reconnected following CB-AdvA when compared with CFCA (2/25, 8% vs. 11/29, 37.9%; P = 0.01). In the CFCA group, the mean CF per-vein was lower in reconnecting veins when compared with those persistently isolated (10.9 ± 2.7 vs. 18.6 ± 3.1 g; P < 0.001). In the CB-AdvA group, late PV reconnection was associated with warmer nadir temperature (-48.9 ± 5.1 vs. -51.2 ± 4.7°C; P = 0.05) and longer time-to-isolation (71.1 ± 20.2 vs. 50.2 ± 32.9 s; P = 0.03). CONCLUSION: The rate of late PV reconnection is significantly lower following CB-AdvA when compared with CFCA as index procedure. Lower CF values and warmer nadir temperature with longer time to effect were more frequently associated with PV reconnections in the setting of CFCA and CB-AdvA.

Anatomic predictors of phrenic nerve injury in the setting of pulmonary vein isolation using the 28-mm second-generation cryoballoon.

BACKGROUND: Phrenic nerve injury (PNI) is the most frequently observed complication during pulmonary vein (PV) isolation using the second-generation cryoballoon. OBJECTIVE: The purpose of this study was to analyze anatomic predictors based on preprocedural computed tomographic imaging data. METHODS: Forty-one patients with PNI during the procedure and 123 age-, gender-, and body mass index-matched controls were included. A total of 343 right PVs were evaluated for axial/coronal orientation, ostial diameters with cross-sectional area, ovality index, and branching pattern. External angle between the right superior pulmonary vein (RSPV) and the anterolateral wall of the left atrium (LA) was measured (RSPV-LA angle). Distance from this vertex to the superior vena cava (SVC) was considered the RSPV-SVC distance. RESULTS: For the RSPV, more anterosuperior orientation, larger dimensions, shorter RSPV-SVC distance, and more obtuse RSPV-LA angle (all P <.001) were associated with PNI on univariate analysis. Independent variables after multivariable analysis were RSPV-LA angle (odds ratio 1.03 per degree, 95% confidence interval 1.01-1.04, P <.001) and RSPV area (odds ratio 1.2 per mm², 95% confidence interval 1.1-1.3, P <.001), with a cutoff value ≥141° for RSPV-LA angle (91% sensitivity, 85% specificity) and ≥275 mm² for RSPV area (88% sensitivity, 85% specificity). RIPV area was an independent predictor for PNI at RIPV. A right-sided long common trunk was seen exclusively in 3 patients in the PNI group. CONCLUSION: Preprocedural anatomic assessment of right PVs is useful in evaluating the risk of PNI. Ostial vein area and external RSPV-LA angle measurement showed excellent predictive value for PNI at the RSPV.

'The role of novel oral anticoagulants in patients undergoing cryoballoon ablation for atrial fibrillation'.

AIM: Peri-procedural thromboembolic (TE) and hemorrhagic events are complications of major concern for patients undergoing cryoballoon (CB) ablation for atrial fibrillation (AF). While peri-procedural anticoagulation management could decrease the incidence of these complications, data on CB ablation are scarce. The role of novel oral anticoagulants (NOACs) has not been thoroughly tested in this population. METHODS: In the present study, we sought to assess acute peri-procedural complications in patients undergoing CB ablation for AF under different anticoagulation regimens; anticoagulation administration was performed according to the CHA2DS2-VASc score guidelines. To the best of our knowledge, this is the first study that compares 1) uninterrupted warfarin, 2) bridging therapy with low molecular weight heparin (LMWH), 3) aspirin and 4) NOACs in this subgroup of patients. RESULTS: NOACs were as effective as uninterrupted warfarin in terms of bleeding complications and TE events. Surprisingly, the aspirin group had more hemorrhagic complications than both the warfarin and NOACs groups. CONCLUSION: In the current study, the use of NOACs was an effective and safe approach in CB ablation.

On the Quest for the Best Freeze: Predictors of Late Pulmonary Vein Reconnections After Second-Generation Cryoballoon Ablation.

BACKGROUND: The second-generation cryoballoon is effective in achieving acute pulmonary vein isolation (PVI) and favorable clinical outcome. To date, no data are available on factors affecting late PV reconnection after second-generation cryoballoon ablation. METHODS AND RESULTS: A total of 29 consecutive patients (25 male, 86.2%; mean age 57.8±13.8 years) underwent a repeat procedure, after a mean 11.6±4.5 months (range, 3.5-19.7 months), after index ablation using the 28-mm second-generation cryoballoon. All repeat ablations were performed using a 3-dimensional electroanatomical mapping system. Among all 115 PVs, including 1 left common ostiums (LCOs), 25 (21.7%) showed a PV reconnection in 20 patients (1.25 per patient). Persistent PVI could be documented in 90 of 115 PVs (78.2%). In 9 of 29 patients (31%), all PVs were electrically isolated. In the multivariable analysis, time to PVI (P=0.03) and failure to achieve -40°C within 60 s (P=0.05) independently predicted late PV reconnection. At receiver-operator curve analysis, time to PVI <60 s identified the absence of PV reconduction (sensitivity, 86.7%; specificity, 86.2%; positive predictive value, 59.1%; and negative predictive value, 96.4%; area under the curve, 0.85; confidence interval, 0.73-0.97; P<0.001). CONCLUSIONS: The rate of late PV reconnection after second-generation cryoballoon ablation is low (1.25 PVs/patient). Faster time to isolation and achievement of -40°C within 60 s independently predict durable PVI. In addition, 60-s cut-off for time to PVI indicates persistent isolation with 96.4% negative predictive value. These parameters might guide the operator whether to perform further applications to ensure a long-lasting PVI.

Asymptomatic Brugada Syndrome: Clinical Characterization and Long-Term Prognosis.

BACKGROUND: Among Brugada syndrome patients, asymptomatic individuals are considered to be at the lowest risk. Nevertheless, arrhythmic events and sudden cardiac death are not negligible. Literature focused on this specific group of patients is sparse. The purpose of this study is to investigate the clinical characteristics, management, and long-term prognosis of asymptomatic Brugada syndrome patients. METHODS AND RESULTS: Patients presenting with spontaneous or drug-induced Brugada type I ECG and no symptoms at our institution were considered eligible. A total of 363 consecutive patients (200 men, 55.1%; mean age, 40.9±17.2 years; 41 [11.3%] with spontaneous type I ECG) were included. Electrophysiological study was performed in 321 (88.4%) patients, and ventricular arrhythmias were induced in 32 (10%) patients. An implantable cardioverter defibrillator was implanted in 61 (16.8%) patients. After a mean follow-up time of 73.2±58.9 months, 9 arrhythmic events occurred, accounting for an annual incidence rate of 0.5%. Event-free survival was 99.0% at 1 year, 96.2% at 5 years, and 95.4% at 10 and 15 years. Univariate analysis identified as risk factors: electrophysiological study inducibility (hazard ratio, 11.4; P<0.01), spontaneous type I (hazard ratio, 4.0; P=0.04), and previous sinus node dysfunction (hazard ratio, 8.0; 95% confidence interval, 1.0-63.9; P=0.05). At the multivariate analysis, only inducibility remained significant (hazard ratio, 9.1; P<0.01). CONCLUSIONS: Arrhythmic events in asymptomatic Brugada syndrome patients are not insignificant. Ventricular arrhythmia inducibility, spontaneous type I ECG, and presence of sinus node dysfunction might be considered as risk factors and used to drive long-term management.

Complications in the setting of percutaneous atrial fibrillation ablation using radiofrequency and cryoballoon techniques: A single-center study in a large cohort of patients.

BACKGROUND: The aim of this study was to assess the overall incidence of complications in a large sample of consecutive patients having undergone pulmonary vein (PV) isolation, evaluating also the rate of complications in radiofrequency (RF) and cryoballoon (CB) ablation technologies. METHODS AND RESULTS: From January 2008 to December 2014, 1352 consecutive PV isolation procedures were performed in our center; a total amount of 1233 AF ablation procedures fulfilling inclusion criteria was finally taken into consideration for our analysis. A total of 642 procedures were performed using RF ablation technology and 591 using CB system. Serious adverse events occurred in 36 procedures (2.9%): specifically, vascular complications in 14 (1.1%); cardiac tamponade in 13 (1.0%); a thromboembolic event in 4 (0.3%); and atrial-esophageal fistula, PV intramural hematoma, retroperitoneal hematoma, pleural hematoma and persisting phrenic nerve palsy all occurred in 1 patient individually (0.1%). No deaths related to the procedure occurred. The complication rate did not significantly differ in the RF and CB groups (respectively, 3.6% vs 2.2%; p=0.1). Complication rates considerably decreased over the study period from 4.67% in 2008 to 1.55% in 2014. Interestingly, each 1-point increase in the CHA2DS2-VASc score was found to increase by 51% the likelihood of a serious adverse event. CONCLUSIONS: The incidence of serious adverse events following AF ablation procedures was 2.9%. Vascular complications were the most frequent complication followed by tamponade and thromboembolic events. The rate of complications considerably decreased over time. CHA2DS2-VASc score was found to be associated with higher risk of complications.

Impact on Clinical Outcome of Premature Interruption of Cryoenergy Delivery Due to Phrenic Nerve Palsy During Second Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation.

INTRODUCTION: Right phrenic nerve paralysis (PNP) is the most frequently observed complication occurring during cryoballoon ablation (CB). Our aim was to analyze the impact of the premature interruption (PI) of cryoenergy delivery in a large series of consecutive patients during ablation in the right-sided veins on clinical outcome. METHODS AND RESULTS: All consecutive patients having undergone second-generation CB ablation for paroxysmal atrial fibrillation (AF) from July 2012 to September 2014 were included in our analysis. Exclusion criteria were persistent AF, presence of an intracavitary thrombus, uncontrolled heart failure, moderate or severe valvular disease, left atrium (LA) diameter ≥55 mm, and contraindications to general anesthesia. A total 287 consecutive patients with drug-resistant paroxysmal AF having undergone pulmonary vein isolation by means of CB technology (male 65%, age 57.6 ± 13.1 years) were included. The incidence of PNP in the study population was 8.0% (23/287). At a mean follow-up of 11.5 ± 3.9 months, the success rate without antiarrhythmic therapy was 81.6%. Patients with PNP had similar rates of AF recurrence compared with those without PNP (17.4% vs. 17.8%; P = 0.9); the former had a mean follow-up of 10.9 ± 3.7 months, the latter 11.8 ± 4.5 months (P = 0.3). CONCLUSION: Conclusion: Our findings show that patients in whom freezing was interrupted due to PNP had a similar outcome on 1-year follow-up compared with those in whom freezing cycles were completed in the septal veins. No baseline clinical or procedural characteristics were found to predict AF recurrence in patients having experienced PNP.

One Year Incidence of Atrial Septal Defect after PV Isolation: A Comparison Between Conventional Radiofrequency and Cryoballoon Ablation.

BACKGROUND: Transseptal (TS) catheterization is needed to access the left heart during pulmonary vein isolation (PVI) procedures. In the radiofrequency (RF) ablation procedure, left atrial access is commonly achieved with a double TS puncture; cryoballoon (CB) ablation usually requires only a single TS puncture. Our aim was to compare the incidence of iatrogenic septal defect (IASD) between double transseptal conventional RF and CB ablation. METHODS AND RESULTS: Individuals having undergone PVI as index procedure by RF or CB ablation and a subsequent transesophageal echocardiography examination during postablation follow-up in our center were consecutively included. A total of 127 patients formed the study group (92 males; mean age 60 ± 11 years). IASD was present in 17 patients (13.4%) after a mean follow-up time of 11.6 months. The incidence of IASD at 1-year follow-up following PVI was significantly higher in the CB ablation group compared with the RF ablation group (22.2% vs 8.5%; P = 0.03). Mean IASD diameter was larger in the CB group (0.60 cm × 0.50 cm vs 0.44 cm × 0.35 cm) without statistical significance. Only left to right atrial shunt was observed. No adverse events were recorded in these patients during the follow-up. CONCLUSIONS: the incidence of IASD at 1-year follow-up following CB ablation procedure for PVI is significantly higher with respect to RF procedures. Although no adverse clinical events were recorded in patients with persistence of IASD, more detailed echocardiographic examinations might be advised in all individuals exhibiting this finding.