Low incidence of permanent complications during catheter ablation for atrial fibrillation using open-irrigated catheters: a multicentre registry.

AIMS: Despite catheter ablation (CA) has become an accepted treatment option for symptomatic, drug-resistant atrial fibrillation (AF), the safety of this procedure continues to be cause for concern. The aim of the present study was to assess the incidence of complications with permanent sequelae of CA for AF using open-irrigated catheters in a contemporary, unselected population of consecutive patients. METHODS AND RESULTS: From 1 January 2011 to 31 December 2011, data from 2167 consecutive patients who underwent CA for AF using an open-irrigated catheter in 29 Italian centres were collected. All the complications occurring to the patient from admission to the 30th post-procedural day were recorded. No procedure-related death was observed. Complications occurred in 81 patients (3.7%): 46 patients (2.1%) suffered vascular access complications; 13 patients (0.6%) cardiac tamponade, successfully drained in all the cases; six patients (0.3%) arterial thromboembolism (four transient ischaemic attack and two ischaemic strokes); five (0.2%) patients conservatively treated pericardial effusion; three patients (0.1%) phrenic nerve paralysis; three patients (0.1%) pericarditis; three patients (0.1%) haemothorax, and two patients (0.1%) other isolated adverse events. At multivariate analysis, only female sex [odds ratio (OR) 2.5, confidence interval (CI): 1.5-3.7, P < 001] and the operator experience (OR 0.5, CI: 0.4-0.7, P < 001) related to the complications. Only five (0.2%) patients developed permanent sequelae from their complications. CONCLUSION: Catheter ablation for AF with the use of open-irrigated catheters is currently affected by a very low rate of complications leading to permanent sequelae.

[Risk stratification in Brugada syndrome]. / Stratificazione del rischio nella sindrome di Brugada.

Individuals with type 1 Brugada ECG pattern may suffer from malignant ventricular arrhythmias (Brugada syndrome). Patients with Brugada syndrome and documented cardiac arrest should receive an implantable cardioverter-defibrillator. In the remaining subjects, the best management is controversial. Many data suggest that patients with syncope, particularly if they have a spontaneous type 1 ECG pattern, have a significant risk. In the remaining population of asymptomatic subjects, the risk is lower but not negligible. How to manage these latter cases is an unsolved issue. The usefulness of the electrophysiological study (EPS) in risk stratification, i.e. inducibility of sustained ventricular tachycardia/fibrillation, is controversial. Indeed, some authors strongly support the prognostic value of EPS, while others completely deny its usefulness. We recently published our experience concerning the usefulness of a combined approach that considered both clinical data and EPS results; 320 patients (258 males, mean age 43 years) with type 1 ECG were enrolled. No patient had previous cardiac arrest; 54% of patients had a spontaneous and 46% a drug-induced type 1 ECG. One third had syncope, two thirds were asymptomatic; 245 patients underwent EPS; 110 patients received an implantable defibrillator. Patients were followed up for 40 months. During follow-up, 17 patients had major arrhythmic events (MAE) (14 resuscitated ventricular fibrillations and 3 sudden deaths). Both spontaneous type 1 ECG and syncope significantly increased the risk (8.6% and 10.4% event rates vs 2.8% and 1.3%). MAE occurred in 14% of subjects with positive EPS, in no subjects with negative EPS, and in 5.3% of subjects without EPS. All MAE occurred in subjects who had ≥ 2 risk factors (syncope, family history of sudden death and positive EPS). Among these patients, those with spontaneous type 1 ECG had a 30% event rate. In subjects with drug-induced type 1 MAE were rare. In conclusion, 1) in subjects with the Brugada type 1 ECG neither a single clinical risk factor nor EPS alone are able to identify subjects at the highest risk; 2) a multiparametric approach (including syncope, family history of sudden death and positive EPS) helps to identify populations at the highest risk; 3) subjects at the highest risk are those with a spontaneous type 1 ECG and ≥ 2 risk factors; 4) the remainder is at low risk.

Risk stratification in individuals with the Brugada type 1 ECG pattern without previous cardiac arrest: usefulness of a combined clinical and electrophysiologic approach.

AIMS: Risk stratification in individuals with type 1 Brugada electrocardiogram (ECG) pattern (type 1 ECG) for primary prevention of sudden death (SD). METHODS AND RESULTS: Three hundred and twenty patients (258 males, median age 43 years) with type 1 ECG were enrolled. No patient had previous cardiac arrest. Fifty-four per cent of patients had a spontaneous and 46% a drug-induced type 1 ECG. One-third had syncope, two-thirds were asymptomatic. Two hundred and forty-five patients underwent electrophysiologic study (EPS) and 110 patients received an implantable cardiac defibrillator (ICD). During follow-up [median length 40 months (IQ20-67)], 17 patients had major arrhythmic events (MAE) (14 resuscitated ventricular fibrillation (VF) and three SD). Both a spontaneous type 1 ECG and syncope significantly increased the risk (2.6 and 3.0% event rate per year vs. 0.4 and 0.8%). Major arrhythmic events occurred in 14% of subjects with positive EPS, in no subjects with negative EPS and in 5.3% of subjects without EPS. All MAE occurred in subjects who had at least two potential risk factors (syncope, family history of SD, and positive EPS). Among these patients, those with spontaneous type 1 ECG had a 30% event rate. CONCLUSION: (1) In subjects with the Brugada type 1 ECG, no single clinical risk factor, nor EPS alone, is able to identify subjects at highest risk; (2) a multiparametric approach (including syncope, family history of SD, and positive EPS) helps to identify populations at highest risk; (3) subjects at highest risk are those with a spontaneous type 1 ECG and at least two risk factors; (4) the remainder are at low risk.

How many atrial fibrillation ablation candidates have an underlying supraventricular tachycardia previously unknown? Efficacy of isolated triggering arrhythmia ablation.

AIMS: Supraventricular tachycardia may trigger atrial fibrillation (AF). The aim of the study was to evaluate the prevalence of supraventricular tachycardia (SVT) inducibility in patients referred for AF ablation and to evaluate the effects of SVT ablation on AF recurrences. METHODS AND RESULTS: Two hundred and fifty-seven patients (185 males; mean age: 53.4 ± 14.6 years) referred for AF ablation were studied. In all patients only AF relapses had been documented in the clinical history. Twenty-six patients (10.1%; mean age: 43.4 ± 13.3 years; 17 males) had inducible SVT during electrophysiological study and underwent an ablation targeted only at SVT suppression. Ablation was successful in all 26 patients. The ablative procedures are: 12 slow-pathway ablations for atrioventricular nodal re-entrant tachycardia; 9 concealed accessory pathway ablations for atrioventricular re-entrant tachycardia; and 5 focal ectopic atrial tachycardia ablations. No recurrences of SVT were observed during the follow-up (21 ± 11 months). Two patients (7.7%) showed recurrence of at least one episode of AF. Patients with inducible SVT had less structural heart disease and were younger than those without inducible SVT (interventricular septum thickness: 8.4 ± 1.6 vs. 11.0 ± 1.4 mm, P < 0.01; left atrial diameter: 37.0 ± 3.0 vs. 44.0 ± 2.2 mm, P < 0.01; age: 43.4 ± 13.3 vs. 57.3 ± 11.2 years, P < 0.01). Prevalence of paroxysmal AF was higher in patients with inducible SVT when compared with those with only AF (84.6 vs. 24.6%, P < 0.01). CONCLUSION: A significant proportion of candidates to AF ablation are inducible for a SVT. SVT ablation showed a preventive effect on AF recurrences. Those patients should be selected for simpler ablation procedures tailored only on the triggering arrhythmia suppression.

Image integration increases efficacy of paroxysmal atrial fibrillation catheter ablation: results from the CartoMerge Italian Registry.

AIMS: The aim of this study was to investigate whether circumferential pulmonary vein (PV) isolation guided by image integration improves the procedural and clinical outcomes of atrial fibrillation (AF) ablation in comparison with segmental PV isolation and circumferential PV isolation guided by three-dimensional (3D) electroanatomical mapping alone. METHODS AND RESULTS: Procedural and clinical outcomes of 573 patients who underwent their first catheter ablation for paroxysmal AF between January 2005 and April 2007 were collected from 12 centres. We evaluated three techniques: segmental ostial PV isolation (SOCA group, 240 patients), circumferential PV isolation guided by electroanatomical mapping (CARTO group, 107 patients), and circumferential PV isolation guided by electroanatomical mapping integrated with magnetic resonance/computed tomographic images of the left atrium (MERGE group, 226 patients). Procedure duration proved to be shorter in MERGE group patients than in CARTO group patients (P < 0.04), but longer than in SOCA group patients (P < 0.0001). During follow-up, atrial tachyarrhythmias relapsed more frequently in SOCA group patients (44.6%) and CARTO group patients (41.7%) than in MERGE group patients (22.6%; P < 0.0001). CONCLUSION: In patients with paroxysmal AF, circumferential PV isolation guided by image integration significantly improves clinical outcome in comparison with both circumferential PV isolation guided by 3D mapping alone and with segmental electrophysiologically guided PV isolation.

High prevalence of cooled tip use as compared with 8-mm tip in a multicenter Italian registry on atrial fibrillation ablation: focus on procedural safety.

BACKGROUND: Whether cooling catheters should be preferred for atrial fibrillation (AF) ablation is not yet clear. METHODS: From April 2005 to October 2006, 991 (74% men) consecutive patients who underwent AF ablation were prospectively enrolled in 10 Italian centers. For the present subanalysis, patients were ranked in the two study groups on the basis of the catheter system chosen: 8-mm tip was used in 86 patients (9% conventional group) and open-irrigated tip in 905 patients (91% cooled group). RESULTS: The registry clinical data of both groups showed marked heterogeneity due to the fact that the higher number of patients of the cooled group had longer AF history (4.9+/-4.1 versus 1.2+/-1.8 years; P=0.0001), permanent/persistent AF (41.2 versus 27.9%; P=0.01), and larger left atrium (LA) size (44.1+/-6.2 versus 33.4+/-10.5 mm; P

Early complications of pulmonary vein catheter ablation for atrial fibrillation: a multicenter prospective registry on procedural safety.

BACKGROUND: Data on the procedural safety of pulmonary vein radiofrequency catheter ablation for atrial fibrillation (AF) are as yet scant. OBJECTIVE: The aims of the present study were to prospectively evaluate the incidence of early complications of pulmonary vein ablation for AF in an unselected population of consecutive patients, and to identify possible predictors. METHODS: From April 2005 to October 2006, data from 1,011 consecutive patients who were undergoing radiofrequency catheter ablation for every type of AF in 10 Italian centers were collected. All complications occurring from the admission of the patient up to the 30th day were considered. RESULTS: No procedure-related death was observed. Complications occurred in 40 patients (3.9%): 12 (1.2%) had peripheral vascular complications, 8 (0.8%) had conservatively treated pericardial effusion, 6 (0.6%) had cardiac tamponade (successfully drained), 5 (0.5%) had cerebral embolisms, 4 (0.4%) presented pulmonary vein stenosis >50%, and 5 (0.5%) presented other isolated adverse events. History of coronary artery disease (odds ratio 5,603, 95% confidence interval 1,559 to 20,139, P < .008) characterized patients who presented with hemorrhagic complications. CONCLUSION: Early complications of pulmonary vein catheter ablation seem to be fewer than in the early years of AF ablation, but still occur in 3.9% of procedures.

Common atrial flutter and atrial fibrillation are not always two stages of the same disease. A long-term follow-up study in patients with atrial flutter treated with cavo-tricuspid isthmus ablation.

OBJECTIVE: Both atrial flutter and atrial fibrillation (AF) frequently develop in the same patient. There is therefore reasonable doubt that flutter ablation may not solve the clinical problem, owing to the occurrence/recurrence of AF. The aim of this study was to establish whether cavo-tricuspid isthmus ablation is curative in patients with common atrial flutter alone or combined with AF. METHODS: One hundred and forty-one patients (114 male, 27 female, mean age 63 +/- 10 years) who had cavo-tricuspid isthmus ablation were followed up for 44 +/- 20 months. Before ablation, 48 patients had only atrial flutter (group A), whereas 93 patients had both atrial flutter and AF. Among the latter, during antiarrhythmic therapy, 31 patients had only atrial flutter (group B1), whereas 62 patients (group B2) continued to experience both arrhythmias. RESULTS: During follow-up, 27% of group A and 61% of group B patients had documented recurrent AF (P < 0.001). AF recurred in 51% of group B1 and in 66% of group B2 patients (P = NS). Permanent AF occurred in 6% of group A, 3% of group B1 and 21% of group B2 (P < 0.01). Specific symptom scale scores significantly decreased in all groups, particularly in group A. Two patients of group B had cerebral ischaemic attacks. CONCLUSIONS: Over a long-term follow-up, cavo-tricuspid isthmus ablation is curative in >70% of patients with atrial flutter alone. Therefore, if no AF is documented, more extensive ablation is not needed. By contrast, cavo-tricuspid isthmus ablation is frequently unable to prevent AF in patients with both atrial flutter and AF, although in some cases a significant clinical benefit may be obtained.

Pace mapping of Koch's triangle reduces risk of atrioventricular block during ablation of atrioventricular nodal reentrant tachycardia.

INTRODUCTION: Slow pathway (SP) ablation of AV nodal reentrant tachycardia (AVNRT) can be complicated by second- to third-degree AV block. We assessed the usefulness of pace mapping of Koch's triangle in preventing this complication. METHODS AND RESULTS: Nine hundred nine consecutive patients undergoing radiofrequency ablation of AVNRT were analyzed. Group 1 (n=487) underwent conventional slow pathway ablation. Group 2 (n=422) underwent ablation guided by pace mapping of Koch's triangle, which located the anterogradely conducting fast pathway (AFP) based on the shortest St-H interval obtained by stimulating the anteroseptal, midseptal, and posteroseptal aspects of Koch's triangle. In group 2, AFP was anteroseptal in 384 (91%), midseptal in 33 (7.8%), and posteroseptal or absent in 5 (1.2%). In 32 of 33 patients with midseptal AFP, slow pathway ablation was performed strictly in the posteroseptal area. In 4 of 5 patients with posteroseptal or no AFP, retrograde fast pathway was ablated. Two patients refused ablation. Persistent second- to third-degree AV block was induced in 7 (1.4%) of 487 group 1 patients versus 0 (0%) of 422 group 2 patients (P=0.038). Ablation was successful in all patients in whom ablation was performed. CONCLUSION: Pace mapping of Koch's triangle identifies patients in whom the AFP is absent or is abnormally close to the slow pathway. In these cases, guiding ablation helps to avoid AV block.

Different clinical courses and predictors of atrial fibrillation occurrence after transisthmic ablation in patients with preablation lone atrial flutter, coexistent atrial fibrillation, and drug induced atrial flutter.

The aim of this prospective study was to compare the long-term follow-up after transisthmic ablation of patients with preablation lone atrial flutter, coexistent AF, and drug induced atrial flutter to determine if postablation AF followed a different clinical course and displayed different predictors in these groups. The study evaluated 357 patients who underwent transisthmic ablation for typical atrial flutter. These were divided into four groups according to their preablation history. Group A included patients with typical atrial flutter and without preablation AF (n=120, 33.6%). Group B included patients with preablation AF and spontaneous atrial flutter (n=132, 37.0%). Group C patients had preablation AF and atrial flutter induced by treatment with IC drugs (propafenone or flecainide) (n=63, 17.6%) Group D included patients with preablation AF and atrial flutter induced by treatment with amiodarone (n=42, 11.8%). During a mean follow-up of 15.2 double dagger 10.6 months (range 6-55 months) AF occurred more frequently in groups B (56.1%) and C (57.1%) patients than in groups A (20.8%, P <0.0001) and D (31.0%, P <0.0001) patients. The results of multivariate analysis revealed that different clinical and echocardiographical variables were correlated with postablation AF occurrence in the different groups. Patients with atrial flutter induced by amiodarone have a significantly lower risk of postablation AF than patients with spontaneous atrial flutter and AF, and those with atrial flutter induced by IC drugs. Different clinical and echocardiographical variables predict postablation AF occurrence in different subgroups of patients.

Ablation of a single pulmonary vein arrhythmic focus triggering several supraventricular arrhythmias.

Pulmonary veins are a well-recognized source of focal ectopies that may trigger atrial fibrillation. Many ablative strategies, in particular ablation of the four pulmonary vein ostia, have been developed in order to cure atrial fibrillation. In some patients, the predominant arrhythmia may be an ectopic atrial tachycardia arising from a pulmonary vein and atrial fibrillation may be only a consequence of rapid atrial activation. There is a paucity of data regarding the electrocardiographic and electrophysiological characteristics of pulmonary vein tachycardia and the ablation strategy of this arrhythmia. In the present paper, we describe a case of a young woman with an arrhythmic focus localized in the right superior pulmonary vein with episodes of atrial tachycardia, paroxysmal atrial fibrillation and atrial flutter, who was successfully treated with transcatheter ablation.

Radiofrequency ablation of atrioventricular nodal reentrant tachycardia: the risk of intraprocedural, late and long-term atrioventricular block. The Veneto Region multicenter experience.

BACKGROUND: Radiofrequency ablation of either the fast or the slow pathway in atrioventricular nodal reentrant tachycardia (AVNRT) can be complicated by transient or permanent atrioventricular (AV) block. Little is known about the possibility of AV block occurring during the first weeks after the procedure and nothing about the risk of AV block during the long-term follow-up. METHODS: To clarify these latter points, from February 1990 to December 2000 we enrolled 510 consecutive patients (56 males, 454 females, mean age 55 +/- 16 years) with AVNRT. The target of ablation was the fast pathway in 29 patients (group A) and the slow pathway in 474 (group B), while in 7 (group C) the slow pathway was targeted after unsuccessful fast pathway ablation. Follow-up was available for 488/510 (95.6%). The length of follow-up was 8.2 +/- 2.4 years in group A, 3.4 +/- 2.4 years in group B (83 group B patients had a follow-up > 6 years: 7.3 +/- 0.8 years), and 7.3 +/- 2.4 years in group C. RESULTS: The success rates were 93, 99 and 100% in the three groups respectively. Intraprocedural II-III degree AV block occurred in 6/29 patients (20%) of group A, in 11/474 patients (2.3%) of group B and in 3/7 patients (42%) of group C. In all patients of groups A and C, the II-III degree AV block was transient. In contrast, in 6/474 patients of group B (1.2%, 2 II degree and 4 III degree AV block) the block still persisted at the end of the procedure. Within 7 days of the procedure, a late persistent II-III degree AV block developed in 1/29 patients (3.4%, 1 III degree) of group A, in 1/474 patients (0.2%, 1 II degree) of group B and in 0/7 patients of group C. In 1 out of 6 patients of group B who developed an intraprocedural persistent AV block, 1:1 conduction resumed within the first week. A definitive pacemaker was implanted for permanent III degree AV block in 1/29 patients of group A (3.4%), in 4/474 patients (0.8%) of group B and in 0/7 patients of group C. In the remaining 2/474 group B patients with permanent II degree AV block, a pacemaker was not implanted. During follow-up, no patient presented with a II-III degree AV block related to the ablation. In group B, 2 patients received a pacemaker implant for reasons unrelated to the ablation (1 sick sinus syndrome, 1 progressive intraventricular conduction disease). CONCLUSIONS: The risk of permanent AV block in patients who undergo fast or slow pathway ablation is low and limited to the procedure or to the days immediately after the procedure, and there is no risk of II-III degree AV block during long-term follow-up.