A score model to predict risk of events in patients with Brugada Syndrome.

AIMS: Risk stratification in Brugada Syndrome (BS) remains challenging. Arrhythmic events can occur life-long and studies with long follow-ups are sparse. The aim of our study was to investigate long-term prognosis and risk stratification of BS patients. METHODS AND RESULTS: A single centre consecutive cohort of 400 BS patients was included and analysed. Mean age was 41.1 years, 78 patients (19.5%) had a spontaneous type I electrocardiogram (ECG). Clinical presentation was aborted sudden cardiac death (SCD) in 20 patients (5.0%), syncope in 111 (27.8%) and asymptomatic in 269 (67.3%). Familial antecedents of SCD were found in 184 individuals (46.0%), in 31 (7.8%) occurred in first-degree relatives younger than 35 years. An implantable cardioverter defibrillator (ICD) was placed in 176 (44.0%). During a mean follow-up of 80.7 months, 34 arrhythmic events occurred (event rate: 1.4% year). Variables significantly associated to events were: presentation as aborted SCD (Hazard risk [HR] 20.0), syncope (HR 3.7), spontaneous type I (HR 2.7), male gender (HR 2.7), early SCD in first-degree relatives (HR 2.9), SND (HR 5.0), inducible VA (HR 4.7) and proband status (HR 2.1). A score including ECG pattern, early familial SCD antecedents, inducible electrophysiological study, presentation as syncope or as aborted SCD and SND had a predictive performance of 0.82. A score greater than 2 conferred a 5-year event probability of 9.2%. CONCLUSIONS: BS patients remain at risk many years after diagnosis. Early SCD in first-degree relatives and SND are risk factors for arrhythmic events. A simple risk score might help in the stratification and management of BS patients.

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.

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.

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).

Impact of the high-frequency cutoff of bandpass filtering on ECG quality and clinical interpretation: A comparison between 40Hz and 150Hz cutoff in a surgical preoperative adult outpatient population.

BACKGROUND: In 1990 the American Heart Association (AHA) established a standard 0.05 to 150Hz bandwidth for the routine recording of 12-lead electrocardiograms (ECGs). However, subsequent studies have indicated a very high prevalence of deviations from the recommended cutoffs. OBJECTIVE: This prospective observational study investigates the impact of 40Hz compared to 150Hz high-frequency cutoffs on ECG quality and clinical interpretation in a single-center surgical outpatient population. METHODS: 1582 consecutive adult patients underwent two standard 12-lead ECG tracings using different high-frequency cutoffs (40Hz and 150Hz). Two blinded cardiologists randomly reviewed and interpreted the recordings according to pre-defined parameters (PR and ST segment, Q and T wave abnormalities). An arbitrary score, ranging from 1 to 3, was established to evaluate the perceived quality of the recordings and the non-interpretable ECGs were noted. The tracings were then matched to compare interpretations between 40 and 150Hz filters. RESULTS: A 40Hz high-frequency cutoff resulted in an increased rate of optimal quality ECGs compared to the 150Hz cutoff (93.4% vs 54.6%; p<0.001) and a lower rate of non-interpretable traces (0.25% vs 4.80%; p<0.001). Analyzing the morphologic parameters, no significant differences between the filter settings were found, except for a higher incidence of the J-point elevation in the 40Hz high-frequency cutoff (p=0.007) and a higher incidence of left ventricular hypertrophy in the 150Hz high-frequency cutoff (7.4% vs 5.4%, p<0.001). The latter was noted only in ECGs with borderline QRS amplitudes (between 3.3 and 3.7mV; p<0.001). CONCLUSION: Despite current recommendations, the large deviation from standard high-frequency cutoff in clinical practice does not seem to significantly affect ECG clinical interpretation and a 40Hz high-frequency cutoff of the band-pass filtering may be acceptable in a low risk population, allowing for a better quality of tracings.

Circumferential pulmonary vein isolation as index procedure for persistent atrial fibrillation: a comparison between radiofrequency catheter ablation and second-generation cryoballoon ablation.

AIMS: To assess the 1 year efficacy of pulmonary vein isolation (PVI) as index procedure for persistent atrial fibrillation (PersAF) comparing conventional radiofrequency irrigated-tip catheter ablation (RFCA) using contact-force technology and ablation using the second-generation cryoballoon (CB-AdvA). METHODS AND RESULTS: One hundred consecutive patients (74 male, 74%; mean age 62.4 ± 9.6 years) with drug-refractory PersAF undergoing PVI using RFCA and CB-AdvA 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. Among 100 patients, 50 underwent RFCA whereas 50 CB-AdvA. Mean procedure and fluoroscopy times were 90.5 ± 41.7 vs. 140.2 ± 46.9 min and 14.5 ± 6.6 vs. 19.8 ± 6.8 min in the CB-Adv and in the RFCA group, respectively (P < 0.01). At 1 year follow-up, after a 3 months blanking period (BP), freedom from ATas off-drugs after a single procedure was 60% (28/50 patients) in the CB-Adv and 56% (27/50 patients) in the RFCA group (P = 0.71). Multivariate analysis demonstrated that PersAF duration (P = 0.01) and relapses during BP (P = 0.02) were independent predictors of ATa recurrences following the index procedure. CONCLUSION: Freedom from ATas following PersAF ablation with RFCA and CB-Adv is comparable at 1 year follow-up after a single procedure. Ablation with the CB-Adv is associated with shorter procedure time and radiation exposure as compared with RFCA. Atrial tachyarrhythmias occurrence during BP and longer time of PersAF seem to be significant predictors of arrhythmia recurrences after the index procedure.

Comparison between radiofrequency with contact force-sensing and second-generation cryoballoon for paroxysmal atrial fibrillation catheter ablation: a multicentre European evaluation.

AIMS: Whether pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) using contact force (CF)-guided radiofrequency (RF) or second-generation cryoballoon (CB) present similar efficacy and safety remains uncertain. METHODS AND RESULTS: We performed a multicentre study comparing procedural safety and arrhythmia recurrence after standardized PVI catheter ablation for PAF using CF-guided RF ablation (Thermocool(®) SmartTouch™, Biosense Webster; or Tacticath™, St Jude Medical) (CF group) with second-generation CB ablation (Arctic Front Advance™, Medtronic) (CB group). Overall, 376 patients (mean age 59.8 ± 10.4 years, 280 males) were enrolled in 4 centres: 198 in CF group and 178 in CB group. Procedure was shorter for CB group than for CF group (109.6 ± 40 vs. 122.5 ± 40.7 min, P = 0.003), but fluoroscopy duration and X-ray exposure were not statistically different (P = 0.1 and P = 0.22, respectively). Overall complication rate was similar in both groups: 14 (7.1%) in the CF group vs. 13 (7.3%) in the CB group (P = 0.93). However, transient right phrenic nerve palsy occurred only in CB group (10 patients, 5.6%; P = 0.001 vs. CF group) and severe non-lethal complications (embolic event, tamponade, or oesophageal injury) occurred only in CF group (5 patients, 2.5%; P = 0.03 vs. CB group). No periprocedural death occurred in either group. Single-procedure freedom from any atrial arrhythmias at 18 months post-ablation was comparable in CF group and CB group (76 vs. 73.3%, respectively, log rank P = 0.63). CONCLUSION: Pulmonary vein isolation using CF-guided RF and second-generation CB leads to comparable single-procedure arrhythmia-free survival at up to 18 months with similar overall complication rate.

Persistence of Phrenic Nerve Palsy Following 28-mm Cryoballoon Ablation: A Four-Year Single Center Experience.

BACKGROUND: Phrenic nerve palsy (PNP) is the most frequently observed complication in the setting of cryoballoon (CB) ablation (Arctic Front, Medtronic Inc., Minneapolis, MN, USA). Although, usually transient, resolving before the end of the procedure, persistent PNP (not resolving before the end of procedure) can occur. Literature on persistent PNP after second generation CB ablation is relatively sparse. METHODS: A total of 316 consecutive patients having undergone large 28-mm CB ablation as index procedure in the Heart Rhythm Management Center, UZ Brussels, Belgium, from January 2009 to December 2013 were retrospectively reviewed for the study. Of these 117 patients were treated with the first generation CB (CB1) and 199 patients with the second generation CB (CB2). RESULTS: PNP occurred in 10% of the total population. Persistent PNP was only observed following CB2 ablation which occurred in 4.5% of the group. At a mean follow-up of 11 months, diaphragmatic contraction in persistent PNP patients resumed in 78% (7/9) of the patients. In a final follow-up at 5 and 20 months, PNP persisted in two patients, respectively. PNP during ablation in the right inferior pulmonary vein was only observed in the CB2 group. No predictors of persistency of PNP were observed. CONCLUSION: Persistence of PNP only occurred in the CB2 group in 4.5% of patients. The majority of patients with persistent PNP were asymptomatic. In most of the patients having persistent PNP after ablation, complete phrenic nerve function resumed during follow-up (78%).

One year incidence of iatrogenic atrial septal defect after cryoballoon ablation for atrial fibrillation.

INTRODUCTION: Pulmonary vein (PV) isolation by means of cryoballoon (CB) technology is an effective treatment for symptomatic paroxysmal atrial fibrillation (AF) refractory to antiarrhythmic drug therapy. The CB requires a 15F transseptal sheath that may lead to the creation of a iatrogenic atrial septal defect (IASD). METHODS AND RESULTS: Individuals having undergone PV isolation by the means of CB ablation and a subsequent transesophageal echocardiography (TEE) examination during postablation follow-up were consecutively included. Thirty-nine patients formed the study group (31 male, 76.9%; mean age 57.4 ± 13.7 years). IASD was present in 8 (20%) of them after a mean follow-up time of 11.7 months. Mean diameter of the defect was 0.57 cm × 0.48 cm; only left to right shunt was observed. No adverse events were recorded in these patients during the follow-up. CONCLUSION: IASD after CB ablation of AF is present in up to 20% of patients after 1 year. Although no adverse clinical events were recorded in patients with persistence of IASD, this complication should not be underestimated and systematic echocardiographic examinations might be advised at regular intervals in the follow-up period after CB. Further studies with larger population and follow-up might be required to confirm our findings.

Spontaneous and adenosine-induced pulmonary vein reconnection after cryoballoon ablation with the second-generation device.

INTRODUCTION: Longer observational time and adenosine challenge have proven to be able to detect pulmonary vein (PV) reconnections. The aim of this study was to assess incidence of spontaneous and adenosine-induced PV reconnection after ablation with second-generation cryoballoon (CB-Adv). METHODS AND RESULTS: Fifty consecutive patients (76% male, mean age 60.5 ± 11.9 years) having undergone PV isolation (PVI) using the CB-Adv were enrolled. After isolation, reconnections were evaluated using the Achieve catheter over 30 minutes observation and adenosine administration during isoproterenol infusion (adenosine challenge). Among 200 PVs, isolation was achieved in 190 (95%) during the first application. Lower nadir temperature and longer rewarming time were associated with successful PVI (P = 0.02 and 0.04). Spontaneous (4 veins) and adenosine-induced (4 veins) PV reconnections occurred in the 4% of initially isolated veins (8 veins) in 6 patients (12%). At receiver-operator curve analysis, nadir temperature <-51 °C and rewarming time >28 seconds identified absence of reconnections (sensitivity 100% and 87%, area under the curve 0.75 and 0.72). Patients with right-sided early branching frequently experienced reconnections (P < 0.01). After a mean follow-up of 7.0 ± 1.7 months, 86% of patients were free from atrial fibrillation. None of those with PV reconnections experienced recurrences. CONCLUSIONS: The incidence of spontaneous and adenosine-induced PV reconnection following ablation with the novel CB-Adv is very low occurring in 4% of initially isolated veins. Nadir temperature <-51 °C and rewarming time >28 seconds identified absence of acute reconnections, thus avoiding prolonged waiting time and adenosine challenge in such cases.

Clinical characteristics, management, and prognosis of elderly patients with Brugada syndrome.

BACKGROUND: The clinical course and prognosis of Brugada syndrome (BS) in the elderly is unknown. The purpose of this study was to investigate the clinical characteristics, management, and prognosis of BS in an elderly population. METHODS AND RESULTS: A total of 437 patients with BS were included in this study. Patients were categorized in 2 groups according to the age at the time of diagnosis: <60 years (N = 363) and ≥60 years (N = 74). Moreover, an elderly patients' subgroup analysis was performed between patients with an age between 60 and 70 years (N = 49) and subjects older than 70 years (N = 25). Among elderly patients (50% male, mean age: 67 ± 6 years), family history of sudden death (SD) and induction of sustained ventricular arrhythmias during programmed ventricular stimulation were less frequent as compared to younger patients. Two patients (3%) had a previous episode of aborted SD. Elderly patients with BS presented more frequently with ECG conduction disturbances or previous transient advanced atrioventricular block as compared to younger patients. Of the elderly patients, 42% underwent implantable cardioverter defibrillator implantation and 7% received a pacemaker. After a mean follow-up time of 54 ± 18 months, none of the elderly patients with BS older than 70 years experienced documented life-threating ventricular arrhythmias. Family screening was performed in 58 family members and a BS diagnosis was confirmed in 49%. CONCLUSION: The clinical features and the benign prognosis of BS patients older than 70 years likely identify a lower risk category of patients as compared to younger individuals. The device-guided management in this setting remains individualized and sometimes controversial. Moreover, BS diagnosis in the elderly should not be missed, mainly due to the clinical impact on the family of elderly patients.

Comparison of the patient-activated event recording system vs. traditional 24 h Holter electrocardiography in individuals with paroxysmal palpitations or dizziness.

AIMS: Electrocardiographic documentation of symptomatic episodes of palpitations by means of traditional methods such as 24 h Holter monitoring (HM) or loop recorders is challenging. Patient-activated electrocardiography (ECG) recorders have been proved to be a useful tool in the diagnosis of arrhythmias in these patients. However, no comparison studies between the two techniques have been conducted. The aim of this study was to compare the diagnostic value of Holter ECG and a patient-activated event recorder (OMRON portable HeartScan ECG Monitor(®)) (HeartScan) in the detection of arrhythmias in patients with paroxysmal palpitations or dizziness suggestive of cardiac arrhythmias. METHODS AND RESULTS: Patients with paroxysmal palpitations or dizziness were eligible for this study. All patients underwent an HM for 24 h and a 15-day HeartScan after the HM. Six hundred and twenty-five patients (48% male, mean age: 37 ± 11 years) were included in the study. All patients present with normal heart structure, normal baseline 12-lead ECG, and normal echocardiogram. Indications for ECG monitoring were palpitations in 577 patients (92.3%) and dizziness in 48 (7.7%). Holter monitoring offered a clinical diagnosis in 11 patients (1.8%). Conversely, HeartScan diagnosed the clinical arrhythmia in 558 individuals (89%). Detection of symptoms-related arrhythmias by means of HeartScan was significantly higher when compared with HM (P < 0.01). CONCLUSION: The studied system proved to be an efficient event recorder providing the diagnosis of the clinical arrhythmia in 89% of patients with paroxysmal palpitations or dizziness. Further studies are needed to confirm our results.

Pulmonary vein isolation in patients with Brugada syndrome and atrial fibrillation: a 2-year follow-up.

AIMS: Pharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BS) might be challenging as many antiarrhythmic drugs (AADs) with sodium channel blocking properties might expose the patients to the development of ventricular arrhythmias. Moreover, patients with BS and implantable cardioverter-defibrillator (ICD) might experience inappropriate shocks because of AF with rapid ventricular response. The role of pulmonary vein isolation (PVI) in patients with BS and recurrent episodes of AF has not been established yet. In this study, we analysed the outcome of PVI using radiofrequency energy or cryoballoon (CB) ablation at 2 years follow-up. METHODS AND RESULTS: Consecutive patients with BS having undergone PVI for drug-resistant paroxysmal AF were eligible for this study. Nine patients (three males; mean age: 52 ± 26 years) were included. Six patients (67%) had an ICD implanted of whom three had inappropriate shocks because of rapid AF. At a mean 22.1 ± 6.4 months follow-up, six patients (67%) were free of AF without AADs. None of the three patients who had experienced inappropriate ICD interventions for AF had further ICD shocks after ablation. CONCLUSION: In our study PVI can be an effective and safe procedure to treat patients with BS and recurrent episodes of paroxysmal AF.

Second-generation cryoballoon ablation for paroxysmal atrial fibrillation: 1-year follow-up.

BACKGROUND: The novel cryoballoon Advance (CB-A) has proven to achieve significantly lower temperatures and faster pulmonary vein isolation (PVI) times in comparison with the first-generation device. Although acutely very effective, to the best of our knowledge, data on mid-term clinical follow-up is lacking. AIMS: The aim of the study was to analyse the freedom from recurrence of atrial fibrillation (AF) on a 1-year follow-up period, in a series of consecutive patients having undergone PVI with the CB-A for paroxysmal AF (PAF). METHODS AND RESULTS: Forty-two patients [30 male (71%); mean age: 57.9 ± 21.1 years] were included. All patients underwent a procedure with the large 28 mm CB-A. A total 168 PVs were depicted on the pre-procedural computed tomography scan. All PVs (100%) could be isolated with the CB only. The freedom from AF off-antiarrhythmic drug treatment after a single procedure was 78% of patients at a mean 11.6 ± 2.0 months follow-up. If considering a blanking period (BP) of 3 months, success rate was 83%. Phrenic nerve palsy (PNP) was the most frequent complication occurring in 19% of individuals. CONCLUSION: The CB-A is very effective in producing PVI and affords freedom from AF at 12 months follow-up in 83% of patients affected by drug-resistant PAF following a 3-month BP. The most frequent complication observed was PNP which occurred in 19% of patients. All PNP reverted during follow-up.

Prevalence and electrocardiographic characteristics of early repolarization pattern in young teen athletes.

INTRODUCTION: Early repolarization (ERP) is a common electrocardiographic finding. Its potential to cause cardiac arrhythmias has been hypothesized from experimental studies, but it is not known whether there is a clinical association with sudden cardiac arrest. METHODS: 122 subjects (100% males; mean age: 13.5 +/- 2.7 years) were included from a local youth soccer team in Belgium. All subjects underwent physical examination and a 12-lead ECG was taken. The main objective of the study was to evaluate early repolarization patterns and to determine its prevalence. RESULTS: Of the 122 included subjects, 1 subject with Coumel tachycardia was excluded.The overall prevalence of ERP in our study population was 36%, with 9.1% in the inferior leads, 8.2% in the lateral leads and 18.2% both leads. A family history of sudden cardiac death (SCD) was not higher in the group of ERP (N=3; 6.8%) compared to the non-ERP group (N = 4; 5.2%) (P = 0.713). Interestingly, incomplete right bundle-branch block (IRBBB) was significantly lower among all subjects with ERP (N = 15; 34.1%), compared to those without ERP (N = 49; 63%) (P < 0.002). CONCLUSION: ERP is a common finding in young teen athletes. In this population global ERP (both inferior and lateral) is more common than isolated inferior or lateral ERP. Young age might be a contributing factor in causing a more diffuse repolarization abnormality.

Repeat procedure using radiofrequency energy for recurrence of atrial fibrillation after initial cryoballoon ablation: a 2-year follow-up.

AIMS: The ideal energy source needed to perform 're-isolation' of the pulmonary veins (PVs) during a repeat procedure for recurrence of paroxysmal atrial fibrillation (AF) has not been established yet. In this study we analysed the outcome of repeat procedure using radiofrequency (RF) energy after initial cryoballoon (CB) ablation at 2-year follow-up. METHODS AND RESULTS: Consecutive patients having undergone PVs isolation as repeat procedure for recurrent AF after an initial CB ablation were eligible for this study. Twenty-nine patients (22 male 76%, mean age: 55 ± 17 years) were included. Mean time to repeat ablation was 12 ± 7 months. Recovered PV conduction could be documented in a mean 2.45 ± 0.7 veins in each patient. At mean 20.2 ± 10.7 months follow-up, a total of 16 patients (55%) were free of AF at without antiarrhythmic drugs (AADs). An adjunctive 31% was AF free with previously ineffective AADs. A major complication with no permanent clinical sequelae occurred only in one patient. CONCLUSION: Repeat RF ablation following CB in case of AF recurrence is effective and safe.

CPVT: Arrhythmogenesis, Therapeutic Management, and Future Perspectives. A Brief Review of the Literature.

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a primary electrical disease characterized by a normal resting electrocardiogram and induction of malignant arrhythmias during adrenergic stress leading to syncope or sudden cardiac death (SCD). CPVT is caused by mutations in the cardiac ryanodine receptor (RyR2) or in the sarcoplasmic reticulum protein calsequestrin 2 genes (CASQ2). The RyR2 mutations are responsible for the autosomal dominant form of CPVT, while CASQ2 mutations are rare and account for the recessive form. These mutations cause a substantial inballance in the homeostasis of intracellular calcium resulting in polymorphic ventricular tachycardia through triggered activity. Beta blockers were for years the cornerstone of therapy in these patients. Sodium channel blockers, especially flecainide, have an additive role in those not responding in beta blockade. Implantation of defibrillators needs a meticulous evaluation since inappropriate shocks may lead to electrical storm. Finally, cardiac sympathetic denervation might also be an alternative therapeutic option. Early identification and risk stratification is of major importance in patients with CPVT. The aim of the present review is to present the arrhythmogenic mechanisms of the disease, the current therapies applied and potential future perspectives.

Long-term prognosis of drug-induced Brugada syndrome.

BACKGROUND: Patients with drug-induced Brugada syndrome (BS) are considered at a lower risk than those with a spontaneous type I pattern. Nevertheless, they can present arrhythmic events. OBJECTIVE: The purpose of this study was to investigate their clinical characteristics, long-term prognosis and risk factors. METHODS: A consecutive cohort of 343 patients with drug-induced BS was included and compared with 78 patients with a spontaneous type I pattern. RESULTS: The mean age was 40.7 ± 18.3 years. Sudden cardiac death (SCD) was the clinical presentation in 13 (3.8%) and syncope in 86 (25.1%); 244 (71.1%) were asymptomatic. Patients with drug-induced BS were less frequently men (180 (52.5%) vs 63 (80.8%); P < .01), were more frequently asymptomatic (244 (71.1%) vs 44 (56.4%); P < .01), and had less ventricular arrhythmias (VAs) induced during electrophysiology study (41 (13.2%) vs 31 (42.4%); P < .01). An implantable cardioverter-defibrillator was implanted in 128 patients (37.3%). During a median follow-up of 62.5 months (interquartile range 28.9-115.6 months), 34 patients presented arrhythmic events. The event rate was 1.1% person-year (vs 2.3% person-year in patients with a spontaneous type I pattern; P < .01). Presentation as SCD and inducible VAs were independent risk factors significantly associated with arrhythmic events (adjusted hazard ratio 22.0 and 3.5). Drug-induced BS was related to a better prognosis only in asymptomatic individuals. CONCLUSION: Drug-induced BS has a good prognosis if asymptomatic; however, SCD is possible. Clinical presentation as SCD and inducible VAs during electrophysiology study are independent risk factors for arrhythmic events. In asymptomatic patients, proband status and inducible VAs can help to identify patients at higher risk, but further evidence is needed.

'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.

P-wave indices as predictors of atrial fibrillation recurrence after pulmonary vein isolation in normal left atrial size.

AIMS: Prolonged P-wave duration and dispersion are universally accepted noninvasive markers for atrial electrical remodeling. Our aim was to analyze P-wave indices as predictors of atrial fibrillation recurrence after pulmonary vein isolation in patients with normal left atrial size. METHODS: From January 2008 to December 2011, 426 patients with drug-resistant symptomatic paroxysmal atrial fibrillation underwent pulmonary vein isolation as an index procedure by conventional radiofrequency or cryoballoon ablation in our center. Patients with left atrial dilatation, poor-quality electrocardiograms, atrial pacemaker stimulation, and those undergoing repeat procedures were excluded. A total of 201 patients were analyzed during a mean follow-up of 22 ±â€Š16 months. RESULTS: Patients with prolonged P-wave duration had higher rates of atrial fibrillation recurrences compared with those without prolonged P-wave duration (49 vs. 14%; P < 0.001). Atrial fibrillation recurrence was significantly associated with prolonged P-wave duration (129 ±â€Š13 vs. 119 ±â€Š11 ms; P < 0.001) and P-wave dispersion (54 ±â€Š12 vs. 42 ±â€Š10 ms; P < 0.001) compared with those who remained in sinus rhythm. P-wave duration and dispersion were independently associated with atrial fibrillation recurrence (hazard ratio 1.045, 95% confidence interval 1.027-1.063, P < 0.001; and hazard ratio 1.049, 95% confidence interval 1.022-1.078, P < 0.001, respectively), after adjusting for left atrial size and age. CONCLUSION: Prolonged P-wave duration and dispersion were found to be independently associated with higher recurrence rates of atrial fibrillation after pulmonary vein isolation in patients with normal left atrial dimension. Therefore, a prolongation of P-wave indices may help to identify those patients in whom electrical remodeling has already occurred and a more extensive ablation may be indicated.