Left ventricular diastolic dysfunction in atrial fibrillation: predictors and relation with symptom severity.

BACKGROUND: Left ventricular diastolic dysfunction (LVDD) is common in the general population, but its prevalence in atrial fibrillation (AF), predictors for LVDD in AF and the association between LVDD and AF-related symptom severity has not been well studied. METHODS: In 124 consecutive patients (mean age 61 ± 11years, 60% male) with paroxysmal (n = 70) or persistent AF (n = 54) referred for AF catheter ablation, LVDD was evaluated according to current guidelines using transthoracic echocardiography. AF-related symptom severity was quantified using the European Heart Rhythm Association score. RESULTS: LVDD was present in 46 patients (37%). In uni- and multivariable regression analysis, age (OR 1.068 per year, 95% CI 1.023-1.115, P = 0.003) and persistent AF (OR 2.427 vs. paroxysmal AF, 95% CI 1.112-5.3, P = 0.026) were associated with LVDD. LVDD was found in 11% with mild AF symptoms (n = 27) as opposed to 44% in patients with moderate-severe AF symptoms (n = 97, P = 0.002). Thus, the OR for moderate-severe AF symptoms was 6.368 (1.797-22.568, P = 0.004) in the presence of LVDD. CONCLUSIONS: LVDD (1) occurs frequently in AF, (2) is associated with advancing age and AF progression and (3) is correlated with symptom severity in AF.

Catheter ablation of ventricular tachycardias using remote magnetic navigation: a consecutive case-control study.

UNLABELLED: Remote Magnetic Navigation for VT Ablation. BACKGROUND: This study aimed to compare acute and late outcomes of VT ablation using the magnetic navigation system (MNS) to manual techniques (MAN) in patients with (SHD) and without (NSHD) structural heart disease. METHODS: Ablation data of 113 consecutive patients (43 SHD, 70 NSHD) with ventricular tachycardia treated with catheter ablation at our center were analyzed. Success rate, complications, procedure, fluoroscopy, and ablation times, and recurrence rates were systematically recorded for all patients. RESULTS: A total of 72 patients were included in the MNS group and 41 patients were included in the MAN group. Patient age, gender, and right ventricular and left ventricular VT were equally distributed. Acute success was achieved in 59 patients in the MNS group (82%) versus 27 (66%) patients in the MAN group (P = 0.046). Overall procedural time (177 ± 79 vs 232 ± 99 minutes, P < 0.01) and mean patient fluoroscopy time (27 ± 19 vs 56 ± 32 minutes, P < 0.001) were all significantly lower using MNS. In NSHD pts, higher acute success was achieved with MNS (83,7% vs 61.9%, P = 0.049), with shorter procedure times (151 ± 57 vs 210 ± 96, P = 0.011), whereas in SHD-VT these were not significantly different. No major complications occurred in the MNS group (0%) versus 1 cardiac tamponade and 1 significantly damaged ICD lead in the MAN group (4.9%, NS). After follow-up (20 ± 11 vs 20 ± 10 months, NS), VT recurred in 14 pts (23.7%) in the MNS group versus 12 pts (44.4%) in the MAN group (P = 0.047). CONCLUSIONS: The use of MNS offers advantages for ablation of NSHD-VT, while it offers similar efficacy for SHD-VT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 948-954, September 2012).

Hemoptysis after pulmonary vein isolation with a cryoballoon: an analysis of the potential etiology.

In a series of 359 cryoballoon ablations with a complete registry of complications, clinically important hemoptysis requiring readmission was observed in 2 patients. One patient had preexisting bronchiectasis; the other had no previous history of pulmonary disease. In the first patient the guiding wire was very distal in one of the veins and exceptional low freezing temperatures were recorded in the left inferior pulmonary vein. Similarly, in the second patient exceptional low freezing temperatures were recorded in all 4 veins. Four additional patients mentioned hemoptysis at the 3-month follow-up visit, which resolved after temporary cessation of anticoagulation. Hemoptysis can occur after cryoballoon ablation for several reasons, especially when a stringent anticoagulation regimen is adhered to, and when occlusion is associated with very low freezing temperatures.

The magnetic navigation system allows safety and high efficacy for ablation of arrhythmias.

AIMS: We aimed to evaluate the safety and long-term efficacy of the magnetic navigation system (MNS) in a large number of patients. The MNS has the potential for improving safety and efficacy based on atraumatic catheter design and superior navigation capabilities. METHODS AND RESULTS: In this study, 610 consecutive patients underwent ablation. Patients were divided into two age- and sex-matched groups. Ablations were performed either using MNS (group MNS, 292) or conventional manual ablation [group manual navigation (MAN), 318]. The following parameters were analysed: acute success rate, fluoroscopy time, procedure time, complications [major: pericardial tamponade, permanent atrioventricular (AV) block, major bleeding, and death; minor: minor bleeding and temporary AV block]. Recurrence rate was assessed during follow-up (15±9.5 months). Subgroup analysis was performed for the following groups: atrial fibrillation, isthmus dependent and atypical atrial flutter, atrial tachycardia, AV nodal re-entrant tachycardia, circus movement tachycardia, and ventricular tachycardia (VT). Magnetic navigation system was associated with less major complications (0.34 vs. 3.2%, P=0.01). The total numbers of complications were lower in group MNS (4.5 vs. 10%, P=0.005). Magnetic navigation system was equally effective as MAN in acute success rate for overall groups (92 vs. 94%, P=ns). Magnetic navigation system was more successful for VTs (93 vs. 72%, P<0.05). Less fluoroscopy was used in group MNS (30±20 vs. 35±25 min, P<0.01). There were no differences in procedure times and recurrence rates for the overall groups (168±67 vs. 159±75 min, P=ns; 14 vs. 11%, P=ns; respectively). CONCLUSIONS: Our data suggest that the use of MNS improves safety without compromising efficiency of ablations. Magnetic navigation system is more effective than manual ablation for VTs.

Flutter ablation with remote magnetic navigation: comparison between the 8-mm tip, the irrigated tip and a manual approach.

INTRODUCTION: Remote magnetic navigated ablation has proven its feasibility in a large group of arrhythmias. Until now only scarce data are available on the use for atrial flutter. In this study we compared remote magnetic navigation (RMN), using non-irrigated and irrigated tip catheters, to manual radiofrequency ablation for ablating typical atrial flutter. METHODS: The 3 study groups consisted of 17 patients treated with RMN 8-mm tip; 14 patients with RMN irrigated tip; and 24 patients with a manual 8-mm tip. The primary outcome was the number of patients in whom bidirectional isthmus block could be obtained with < or = 15 applications. Secondary end points were the median number of applications needed, the need to switch to a manual irrigated tip catheter, the procedural and fluoroscopy times. RESULTS: There was no significant difference in the primary end point (RMN 8 mm-tip group: 59%, RMN irrigated tip group: 64% and manual group: 83%). The median number of applications needed to obtain block was higher in the RMN groups compared to the manual group. In 5 patients from the RMN 8-mm tip group, 1 in the RMN irrigated tip group and 1 in the manual group, a switch to a manually irrigated tip catheter was performed.There was no difference in fluoroscopy time, but procedural time was significantly longer in the RMN groups compared to the manual group (P= 0.03). CONCLUSIONS: The use of magnetic navigation for the ablation of atrial flutter is feasible but not superior to a manual approach. There was no difference concerning the primary end point of acute success within 15 applications. Overall, more applications were needed and procedure times were longer with RMN but RMN with the irrigating tip is promising.

Cryoablation: how to improve results in atrioventricular nodal reentrant tachycardia ablation?

Ablation for atrioventricular nodal reentry tachycardia is very effective, with a potential for damage to the normal conduction system. Cryoablation is an alternative, as it allows cryomapping, which permits assessment of slow pathway elimination at innocent freezing temperatures, avoiding permanent damage to the normal conduction system. It is associated with shorter radiation times and the absence of heart block in all published data. We discuss in this overview different approaches of cryoenergy delivery (focusing on spot catheter ablation), and how lesion formation is influenced by catheter tip size, application duration, and freezing rate. Some advantages of cryoenergy are explained. Whether these features also apply for an approach with a cryoballoon, e.g. for atrial fibrillation is unclear.

A randomized comparison of transseptal and transaortic approaches for magnetically guided ablation of left-sided accessory pathways.

OBJECTIVES: Radiofrequency catheter ablation of left-sided accessory pathways (APs) can be performed either by a transseptal (TS) or transaortic (TA) approach. When performed manually, these techniques are equally effective. The aim of this prospective randomized study was to compare these approaches using a magnetic navigation system (MNS) (Niobe, Stereotaxis, St. Louis, MO, USA). METHODS: Twenty-two consecutive patients were randomized to undergo ablation of a left-sided AP by either a TS or a TA approach. The MNS was used in all patients for catheter navigation and eventual ablation, after electrophysiology study (EPS) confirmed the presence of left-sided APs. Crossover was allowed after failure of the initial approach. Success rates, procedure, fluoroscopy, and ablation times were compared. RESULTS: Of 11 procedures, 10 (91%) were successful in the TS group. The patient crossed over to the TA approach remained unsuccessful. Successful elimination of the AP was obtained in nine (82%) of 11 of the TA procedures. Of the two patients who crossed over to a TS procedure in the same session, one was successful and one remained unsuccessful. Total procedure time did not differ in both groups (87.1 ± 30.8 vs 90.9 ± 26.5 minutes). When total procedure and patient fluoroscopy times were divided into EPS time, time to first application, to successful application, and time to perform TS puncture or to retrogradely cross the aortic valve, only the last measurement differed significantly for both groups (P < 0.01). Ablation times were comparable in both groups. No major complications occurred. CONCLUSIONS: Our data show that TS and TA approaches are equal in success rate and total procedure, patient fluoroscopy, and ablation time when using the MNS for left-sided AP ablation. However, crossing the aortic valve with the MNS is faster than completing a TS puncture.

Transcranial measurement of cerebral microembolic signals during endocardial pulmonary vein isolation: comparison of three different ablation techniques.

INTRODUCTION: Isolation of the pulmonary veins (PVI) using high ablation energy is an effective treatment for atrial fibrillation (AF) with a success rate of 50-95%; however, postoperative neurological complications still occur in 0.5-10%. In this study the incidence of cerebral microembolic signals (MES) as a risk factor for neurological complications is examined during 3 percutaneous endocardial ablation procedure strategies: segmental PVI using a conventional radiofrequency (RF) ablation catheter, segmental PVI using an irrigated RF tip catheter, and circumferential PVI with a cryoballoon catheter (CB). METHODS AND RESULTS: Thirty patients underwent percutaneous endocardial PVI. Ostial isolation was performed in 10 patients with a conventional 4-mm RF catheter (CRF) and in 10 patients with a 4-mm irrigated RF catheter (IRF). A circumferential PVI was performed in 10 patients with a CB. Transcranial Doppler (TCD) monitoring was used to detect MES in the middle cerebral arteries. The total number of cerebral MES differs significantly among the 3 PVI groups; 3,908 cerebral MES were measured with use of the CRF catheter, 1,404 cerebral MES with use of the IRF catheter, and 935 cerebral MES with use of the CB catheter. CONCLUSION: This study demonstrates a significant difference in cerebral MES during PVI with 3 different ablation procedures. The use of an irrigated RF and a cryoballoon produces significantly fewer cerebral MES than the use of conventional RF for a PVI procedure, suggesting a higher risk for neurologic complications using conventional RF energy during a percutaneous PVI procedure.

Initial experience with catheter ablation using remote magnetic navigation in adults with complex congenital heart disease and in small children.

BACKGROUND: The improved outcomes and increased availability of surgery for congenital heart disease (CHD) over the last three decades have created a small but steadily increasing subset of patients with unique needs: children and adults with complex arrhythmias in the setting of structural cardiac abnormalities. Radiofrequency catheter ablation (RFCA) in these patients, and in small children with normal cardiac anatomy, is effective but challenging. An understanding of specific anatomical and electrophysiological characteristics of these patients and the technical challenges in addressing them are critical to the success of this therapy. Tools specifically designed for intracardiac diagnosis and therapy in anatomically complex and/or small hearts remain scarce. AIMS: We report single-center results from an ongoing registry of all patients with congenital heart disease and all children with complex arrhythmias in which the Magnetic Navigation System (MNS) was used. RESULTS: Included in this report are 12 patients with CHD in whom 17 tachyarrhythmias were treated, and 11 pediatric patients with normal cardiac anatomy who each had a single arrhythmia. The procedures' duration and the duration of fluoroscopy time as well as arrhythmia recurrence rates were comparable to those found in previous reports of procedures performed in adults with structurally normal hearts, and the incidence of complications was quite low. DISCUSSION: In patients with complex congenital malformations, retrograde mapping of the pulmonary venous atrium was feasible, eliminating the need for puncture of the atrial septum, or surgically placed baffle in many cases. Moreover, the design of the catheter eliminated the need for multiple mapping and ablation catheters. CONCLUSION: Our findings suggest that RFCA using the MNS for arrhythmias after surgery for congenital heart disease and in pediatric patients is safe and effective.

One year follow-up after cryoballoon isolation of the pulmonary veins in patients with paroxysmal atrial fibrillation.

AIMS: Pulmonary vein isolation (PVI) with cryoenergy delivered through a balloon is a new approach in the treatment of atrial fibrillation (AF), but long-term follow-up is lacking. The aim of this study was to provide insight in the success rate and the incidence of recurrences. METHODS AND RESULTS: Patients with symptomatic AF despite anti-arrhythmic drugs (AADs) were treated with cryoballoon PVI. Daily transtelephonic ECG monitoring, 24 h Holter-ECG, and an arrhythmia-focused questionnaire were used to document AF. One hundred and forty-one patients completed a follow-up of 457 +/- 252 days. Before ablation, Holter-ECG showed AF in 45%, including 16% continuous AF throughout the recording. Event recording revealed a median AF burden of 26%. The questionnaire showed a median of weekly AF complaints lasting for hours. All but one patient had successful PVI with a single procedure. After ablation, AF (defined as lasting for more than 30 s) was seen in 11% of Holter-ECGs, with 1% continuous AF. The event recording showed an AF burden of 9%. The median patient reported no more AF-related symptoms. Recurrence during the first 3 months was predictive for later recurrence. A second procedure was performed in 24 patients. The freedom of AF was 59% without AADs after 1,2 procedures. Four right phrenic nerve paralyses occurred, all resolving within 6 months. No PV stenoses were observed. CONCLUSION: Pulmonary vein isolation with a cryothermal balloon is an effective treatment for paroxysmal AF, resulting in a clinical success rate comparable to studies involving radiofrequency ablation. Temporary right phrenic nerve paralysis is the most important complication.

Magnetically guided left ventricular lead implantation based on a virtual three-dimensional reconstructed image of the coronary sinus.

AIMS: Left ventricular (LV) lead implantation is feasible using remote magnetic navigation of a guidewire (Stereotaxis, St Louis, MO, USA). A novel software that performs a three-dimensional (3D) reconstruction of vessels based on two or more angiographic views has been developed recently (CardiOp-B system, Paeion Inc., Haifa, Israel). The objective of this paper is to evaluate: (i) the performance of the 3D reconstruction software which reproduce the anatomy of the coronary sinus (CS) and (ii) the efficacy of remotely navigating a magnetic guidewire within the CS based on this reconstruction. METHODS AND RESULTS: In patients undergoing cardiac resynchronization therapy implantation, a 3D reconstruction of the CS was performed using the CardiOp-B system. Accuracy of the reconstruction was evaluated by comparing with the CS angiogram. This reconstruction was imported into the Stereotaxis system. On the basis of the reconstruction, magnetic vectors were automatically selected to navigate within the CS and manually adjusted if required. Feasibility of deploying the guidewire and LV lead into the selected side branch (SB), fluoroscopy time (FT) required for cannulation of the target SB, and total FT were also evaluated. Sixteen patients were included. In one case, the software could not reconstruct the CS. The quality of the reconstruction was graded as good in 13 and poor in 2. In 10 cases, manual adjustments to the traced edges of the CS were required to perform the 3D reconstruction, and in 5, no adjustments were required. In 13 patients, the target SB was engaged on the basis of the automatically selected vectors. In two cases, manual modification of the vector was required. Mean total FT was 23 +/- 14 min and the FT required to cannulate the target SB was 1.7 +/- 1.3 min. CONCLUSION: A 3D reconstruction of the CS can be accurately performed using two angiographic views. This reconstruction allows precise magnetic navigation of a guidewire within the CS.

Focal AF-ablation after pulmonary vein isolation in a patient with hypertrophic cardiomyopathy using cryothermal energy.

A 42-year-old man, with a history of hypertrophic cardiomyopathy (HCM), an electrocardiogram pattern of ventricular preexcitation typical for mutations in the PRKAG2 gene, and highly symptomatic paroxysmal drug-resistant atrial fibrillation (AF), underwent successful circumferential isolation of his pulmonary veins using a 28-mm double lumen cryoballoon. Because AF was still inducible with programmed stimulation, fractionated signals were targeted in the left atrium with a conventional cryocatheter. Ablation of an endocardial focus with fractionated potentials at the base of the left appendage terminated the episode and rendered AF noninducible. No recurrence of AF was observed during a 10-month follow-up period.

Face and content validity of the virtual reality simulator 'ScanTrainer®'.

BACKGROUND: Ultrasonography is a first-line imaging in the investigation of women's irregular bleeding and other gynaecological pathologies, e.g. ovarian cysts and early pregnancy problems. However, teaching ultrasound, especially transvaginal scanning, remains a challenge for health professionals. New technology such as simulation may potentially facilitate and expedite the process of learning ultrasound. Simulation may prove to be realistic, very close to real patient scanning experience for the sonographer and objectively able to assist the development of basic skills such as image manipulation, hand-eye coordination and examination technique. OBJECTIVE: The aim of this study was to determine the face and content validity of a virtual reality simulator (ScanTrainer®, MedaPhor plc, Cardiff, Wales, UK) as reflective of real transvaginal ultrasound (TVUS) scanning. METHOD: A questionnaire with 14 simulator-related statements was distributed to a number of participants with differing levels of sonography experience in order to determine the level of agreement between the use of the simulator in training and real practice. RESULTS: There were 36 participants: novices (n = 25) and experts (n = 11) who rated the simulator. Median scores of face validity statements between experts and non-experts using a 10-point visual analogue scale (VAS) ratings ranged between 7.5 and 9.0 (p > 0.05) indicated a high level of agreement. Experts' median scores of content validity statements ranged from 8.4 to 9.0. CONCLUSIONS: The findings confirm that the simulator has the feel and look of real-time scanning with high face validity. Similarly, its tutorial structures and learning steps confirm the content validity.

Gynaecological endoscopic surgical education and assessment. A diploma programme in gynaecological endoscopic surgery.

In recent years, training and education in endoscopic surgery has been critically reviewed. Clinicians, both surgeons as gynaecologist who perform endoscopic surgery without proper training of the specific psychomotor skills, are at higher risk to increased patient morbidity and mortality. Although the apprentice-tutor model has long been a successful approach for training of surgeons, recently, clinicians have recognised that endoscopic surgery requires an important training phase outside the operating theatre. The Gynaecological Endoscopic Surgical Education and Assessment programme (GESEA) recognises the necessity of this structured approach and implements two separated stages in its learning strategy. In the first stage, a skill certificate on theoretical knowledge and specific practical psychomotor skills is acquired through a high-stake exam; in the second stage, a clinical programme is completed to achieve surgical competence and receive the corresponding diploma. Three diplomas can be awarded: (a) the Bachelor in Endoscopy, (b) the Minimally Invasive Gynaecological Surgeon (MIGS) and (c) the Master level. The Master level is sub-divided into two separate diplomas: the Master in Laparoscopic Pelvic Surgery and the Master in Hysteroscopy. The complexity of modern surgery has increased the demands and challenges to surgical education and the quality control. This programme is based on the best available scientific evidence, and it counteracts the problem of the traditional surgical apprentice-tutor model. It is seen as a major step toward standardisation of endoscopic surgical training in general.

Gynaecological Endoscopic Surgical Education and Assessment. A diploma programme in gynaecological endoscopic surgery.

In recent years, training and education in endoscopic surgery has been critically reviewed. Clinicians, both surgeons as gynaecologist who perform endoscopic surgery without proper training of the specific psychomotor skills are at higher risk to increased patient morbidity and mortality. Although the apprentice-tutor model has long been a successful approach for training of surgeons, recently, clinicians have recognised that endoscopic surgery requires an important training phase outside the operating theatre. The Gynaecological Endoscopic Surgical Education and Assessment programme (GESEA), recognises the necessity of this structured approach and implements two separated stages in its learning strategy. In the first stage, a skill certificate on theoretical knowledge and specific practical psychomotor skills is acquired through a high stake exam; in the second stage, a clinical programme is completed to achieve surgical competence and receive the corresponding diploma. Three diplomas can be awarded: (a) the Bachelor in Endoscopy; (b) the Minimally Invasive Gynaecological Surgeon (MIGS); and (c) the Master level. The Master level is sub-divided into two separate diplomas: the Master in Laparoscopic Pelvic Surgery and the Master in Hysteroscopy. The complexity of modern surgery has increased the demands and challenges to surgical education and the quality control. This programme is based on the best available scientific evidence and it counteracts the problem of the traditional surgical apprentice tutor model. It is seen as a major step toward standardization of endoscopic surgical training in general.

Diagnosis of arrhythmias in athletes using leadless, ambulatory HR monitors.

Exercise-related palpitations, vertigo, and syncope may be caused by benign etiologies but can also herald life-threatening arrhythmias. The precise diagnosis of these findings is therefore essential and potentially life saving but often is a challenge for sports physicians and cardiologists. Leadless, ambulatory HR monitors with chest strap transmitters have been designed to steer exercise intensity in athletes with a baseline sinus rhythm. However, they also can capture arrhythmias. Presented here are three cases of varying arrhythmias: atrial fibrillation, atrioventricular nodal reentrant tachycardia, and ectopic atrial tachycardia that demonstrate the utility of HR monitors designed for athletic purposes in facilitating the diagnosis of arrhythmias and guiding appropriate treatment.

Clinical characteristics and acute results of catheter ablation for outflow tract ventricular tachycardia or premature beats.

PURPOSE: Contemporary outcome data of catheter ablation for outflow tract tachycardia (OTT) and ventricular premature beats (VPBs) are rare. The aim of this study was to describe the clinical characteristics, the acute procedure success rate, and the long-term survival of patients who underwent an ablation procedure for OTT or VPBs. METHODS: The study was a single-center retrospective cohort study. All 82 consecutive OTT and VPB first ablation procedures between 1999 and 2009 were included. Patients with structural heart disease were excluded. RESULTS: Mean age was 46 ± 13 years. Forty-three percent of the patients were male. All patients were alive after a median follow-up duration of 31 months (interquartile range, 14-65 months). Eighty-nine percent suffered from palpitations and 12 % had a history of syncope. Ventricular tachycardia was documented in 73 % and monomorphic VPBs in 99 %. Seventy-three percent of the patients were ablated in the right ventricular outflow tract, 15 % in the left ventricular outflow tract, and 12 % in the coronary cusps. Radiofrequency energy was used in 95 % of the patients, cryo energy in 9 %. Acute success was achieved in 78 %. Six patients (7 %) experienced a complication (five pericardial effusions, one pseudo-aneurysm of the femoral artery). Three patients needed pericardiocentesis (4 %). CONCLUSION: Ablation for OTT and VPB is successful in the vast majority of cases, with a low but still existing complication rate. Long-term survival was excellent, underscoring the benign nature of this arrhythmia.

Long-term follow-up after catheter ablation for atrioventricular nodal reentrant tachycardia: a comparison of cryothermal and radiofrequency energy in a large series of patients.

BACKGROUND: Radiofrequency (RF) catheter ablation for atrioventricular nodal reentrant tachycardia (AVNRT) is highly successful but carries a risk for inadvertent atrioventricular block. Cryoablation (cryo) has the potential to assess the safety of a site before the energy is applied. PURPOSE: The aim of this study was to evaluate the long-term efficacy and safety of cryothermal ablation in a large series of patients and compare it to RF. METHODS: All consecutive routinely performed AVNRT ablations from our centre between 1999 and 2007 were retrospectively analysed. RESULTS: In total, 274 patients were elegible: 150 cryoablations and 124 RF. Overall procedural success was 96% (262/274), and equal in both groups, but nine patients were crossed to another arm. Mean fluoroscopy time was longer in the group treated with RF (27 ± 22 min vs. cryo 19 ± 15 min; p = 0.002). Mean procedure time was not different (RF 138 ± 71 min vs. cryo 146 ± 60 min). A permanent pacemaker was necessary in two RF patients. The questionnaire revealed a high incidence of late arrhythmia related symptoms (48%), similar in both groups, with improved perceived quality of life. The number of redo procedures for AVNRT over 4.3 ± 2.5-years follow-up was not statistically different (11% after cryo and 5% after RF). CONCLUSIONS: Our data confirm that cryo and RF ablation with 4-mm tip catheters for AVNRT are equally effective, even after long-term follow-up.