Adding Electroanatomical Mapping to Cryoballoon Pulmonary Vein Isolation Improves 1-Year Clinical Outcome and Durability of Pulmonary Vein Isolation: A Propensity Score-Matched Analysis.

Background: Adding electroanatomical left atrial (LA) voltage mapping to cryoballoon ablation (CBA) improves validation of acute pulmonary vein isolation (PVI). Aims: To determine whether the addition of mapping can improve outcome and PVI durability. Methods: One-year outcome and PV reconnection (PVR) rate at first repeat ablation were studied in 400 AF patients in a propensity-matched analysis (age, AF type, CHA2DS2-VASc score) between Achieve catheter-guided CBA with additional EnSite LA voltage maps performed pre- and post-CBA (mapping group; N = 200) and CT- and Achieve catheter-guided CBA (control group; N = 200). Clinical success was defined as freedom of documented AF or atrial tachycardia (AT) > 30 s. PV reconnection patterns were characterized in repeat ablations. Results: At 1 year, 77 (19.25%) patients had recurrence of AF/AT, significantly lower than in the mapping group: 21 (10.5%) vs. 56 (28%), p < 0.001. Procedure time was shorter (72.2 ± 25.4 vs. 78.2 ± 29.3 min, p = 0.034) and radiation exposure lower (4465.0 ± 3454.6 Gy.cm2 vs. 5940.5 ± 4290.5 Gy.cm2, p = 0.037). Use of mapping was protective towards AF/AT recurrence (HR = 0.348; 95% CI 0.210-0.579; p < 0.001), independent of persistent AF type (HR = 1.723; 95% CI 1.034-2.872; p = 0.037), and LA diameter (HR = 1.055; 95% CI 1.015-1.096; p = 0.006). At repeat ablation (N = 90), persistent complete PVI was seen in 14/20 (70.0%) versus 23/70 (32.9%) in the mapping and conventional group, respectively (p = 0.03). Reconnection rate of the right inferior PV was lower with mapping (10.0% vs. 34,3%, p = 0.035). Conclusions: Adding electroanatomical LA voltage mapping to CBA improves 1-year clinical outcome and lowers both procedure time and radiation exposure. At repeat, use of mapping increases complete persistent PVI mainly by improving PVI durability of the RIPV.

Robotic magnetic navigation-guided catheter ablation establishes highly effective pulmonary vein isolation in patients with paroxysmal atrial fibrillation when compared to conventional ablation techniques.

INTRODUCTION: Pulmonary vein isolation (PVI) is a pivotal part of ablative therapy for atrial fibrillation (AF). Currently, there are multiple techniques available to realize PVI, including: manual-guided cryoballoon (MAN-CB), manual-guided radiofrequency (MAN-RF), and robotic magnetic navigation-guided radiofrequency ablation (RMN-RF). There is a lack of large prospective trials comparing contemporary RMN-RF with the more conventional ablation techniques. This study prospectively compared three catheter ablation techniques as treatment of paroxysmal AF. METHODS: This multicenter, prospective study included patients with paroxysmal AF who underwent their first ablation procedure. Procedural parameters (including procedural efficiency), complication rates, and freedom of AF during 12-month follow-up, were compared between three study groups which were defined by the utilized ablation technique. RESULTS: A total of 221 patients were included in this study. Total procedure time was significantly shorter in MAN-CB (78 ± 21 min) compared to MAN-RF (115 ± 41 min; p < .001) and compared to RMN-RF (129 ± 32 min; p < .001), whereas it was comparable between the two radiofrequency (RF) groups (p = .062). A 3% complication rate was observed, which was comparable between all groups. At 12-month follow-up, AF recurrence was observed in 40 patients (19%) and was significantly lower in the robotic group (MAN-CB 19 [24%], MAN-RF 16 [23%], RMN-RF 5 [8%] AF recurrences, p = .045) (multivariate hazard ratio of RMN-RF on AF recurrence 0.32, 95% confidence interval: 0.12-0.87, p = .026). CONCLUSION: RMN-guided PVI results in high freedom of AF in patients with paroxysmal AF, when compared to cryoablation and manual RF ablation. Cryoablation remains the most time-efficient ablation technique, whereas RMN nowadays has comparable efficiency with manual RF ablation.

Nurse-led care after ablation of atrial fibrillation: a randomized controlled trial.

AIMS: The added value of advanced practitioner nurse (APN) care after ablation of atrial fibrillation (AF) is unknown. The present study investigates the impact of APN-led care on AF recurrence, patient knowledge, lifestyle, and patient satisfaction. METHODS AND RESULTS: Sixty-five patients undergoing AF ablation were prospectively randomized to usual care (N = 33) or intervention (N = 32) group. In addition to usual care, the intervention consisted of an educational session, three consultations spread over 6 months and telephone accessibility coordinated by the APN. Primary outcome was the AF recurrence rate at 6-month follow-up. Secondary outcomes were lifestyle factors (alcohol intake, exercise, BMI, smoking), patient satisfaction and AF knowledge measured at 1 and 6 months between groups and within each group. Study demographics at 1 month were similar, except AF knowledge was higher in the intervention group (8.6 vs. 7, P = 0.001). At 6 months, AF recurrence was significantly lower in the intervention group (13.5 vs. 39.4%, P = 0.014). Between groups, patient satisfaction and AF knowledge were significantly higher in the intervention group, respectively, 9.4 vs. 8.7 (P < 0.001) and 8.6 vs. 7.0 out of 10 (P < 0.001). Within the intervention group, alcohol intake decreased from 3.9 to 2.6 units per week (P = 0.031) and physical activity increased from 224.4 ± 210.7 to 283.8 ± 169.3 (P = 0.048). No changes occurred within the usual care group. Assignment to the intervention group was the only protective factor for AF recurrence [Exp(B) 0.299, P = 0.04] in multivariable-adjusted analysis. CONCLUSION: Adding APN-led care after ablation of AF improves short-term clinical outcome, patient satisfaction and physical activity and decreases alcohol intake.

The present study investigates the added value of advanced practitioner nurse (APN)-led care consisting of an educational session, three consultations spread over 6 months and telephone accessibility coordinated by the APN in patients after ablation of atrial fibrillation (AF). Main findings are The addition of nurse-led care after ablation of AF improves short-term clinical outcome, patient satisfaction and physical activity and decreases alcohol intake.Our study shows that integrating nurse-led care in the post-AF ablation setting is a relatively simple to implement, low-cost intervention with a major impact on patient outcomes and quality of care. These findings encourage including nurse-led care into routine AF ablation follow-up.

Safety and long-term efficacy of cryoballoon ablation for atrial fibrillation in octogenarians: a multicenter experience.

BACKGROUND: Cryoballoon technology (CB-A) has become a cornerstone of atrial fibrillation (AF) ablation in terms of safety and efficacy. Data regarding CB-A in octogenarians are still scarce and limited to single center experiences. The present study sought to analyze the performances of index CB-A in patients older than 80 years-old referring to 3 high-volume European centers. METHODS AND RESULTS: We retrospectively enrolled 95 patients with a median age of 81 [80, 83] years. 62 (65.3%) patients presented with paroxysmal AF and 33 (33.7%) with persistent AF. Mean procedure and fluoroscopy times were 73.8 ± 25.2 and 15.3 ± 7.5 min, respectively. At 12 months and 24 months of follow-up, the overall freedom from AF was 81.1% and 66.6%, respectively. When divided for AF type, freedom from AF was higher in patients with paroxysmal AF (p = 0.007). Cryoballoon ablation was able to significantly improve AF-related symptoms as proven by the significant decrease in EHRA score during the follow-up (p < 0.0001). Phrenic nerve palsy occurred in 8 (8.5%) patients and always resolved during the procedure without affecting procedural outcome. Two major complications occurred (2.1%); one patient experienced pneumonia, successfully treated with antibiotics and non-invasive mechanical ventilation, the latter one experienced acute kidney failure secondary to urosepsis successfully treated by renal replacement therapy. CONCLUSIONS: The present study showed that CB-A is a feasible and effective procedure among octogenarians with a low complication rate. Contemporarily, CB-A can help to alleviate arrhythmia-related symptoms also among this group of subjects.

Efficacy and safety of the second-generation cryoballoon ablation for the treatment of persistent atrial fibrillation in elderly patients.

BACKGROUND: It is expected that ablation procedures will be increasingly offered to a more aged population affected with persistent AF (persAF); however, the clinical outcomes of ablation in this specific population are not well described. We aimed to analyze the efficacy and safety of CB-A in this group of patients compared with a younger cohort. METHODS AND RESULTS: Eighty-three patients with (persAF) aged ≥75 years (group 1; mean age 78.2 ± 3.1 years) and 166 patients also affected with persAF aged <75 years (group 2; mean age 64.3 ± 6.6 years) were included in the study. The primary outcome was freedom from recurrent sustained (>30 seconds) atrial arrhythmias without anti-arrhythmic medication after a blanking period of 3 months. At 2 years, clinical success was achieved in 108 out of 249 patients (43.4%). Median follow-up was 24 months (IQR: 18.4-25.5 months). Older patients suffered from more recurrences than those in the younger cohort ((53/83 patients, 63.9% vs 88/166 patients, 53.0%; P = .03). Thirty (12.0%) patients suffered a complication, but the incidence of complications was not different between both groups. The most frequent complication was transient phrenic nerve injury. CONCLUSIONS: The global 2 years efficacy of CB-A PVI in persAF is 43.4%. A lower success rate is achieved in the older patients (36.1%) compared to the younger age group (47.0%). However, the complication rate was not different between age groups.

Over-the-needle trans-septal access using the cryoballoon delivery sheath and dilator in atrial fibrillation ablation.

BACKGROUND: In the setting of second-generation cryoballoon (CB2) ablation, left atrial (LA) access is generally achieved using a standard sheath (SS) that is exchanged for the 15Fr cryoballoon delivery sheath (CBS) and dilator over a long wire (CBS over-the-wire technique, CBS-W). Our objective was to evaluate the direct use of the CBS to gain LA access, by advancing the latter over the trans-septal needle (CBS over-the-needle technique, CBS-N), under transesophageal echocardiographic (TEE) guidance. METHODS: Consecutive patients who underwent CB2 ablation with the CBS-N technique were evaluated for feasibility of gaining LA access using TEE guidance and fluoroscopy views. Complications related to the LA access were compared with a matched CBS-W control group. Subanalysis (30 CBS-W vs 30 CBS-N patients) evaluated time-to-LA of the CBS: time from superior vena cava (with SS vs CBS) to LA insertion of the CBS, after exchange or directly, respectively. RESULTS: LA access could be achieved in all 505 patients of the CBS-N group, without technique modification or additional equipment. Challenging interatrial septa were noted in 13% of these patients: previous atrial septal defect repair (1%), hypermobile (10%), aneurysmal (1%), and abnormally thickened/fibrotic (1%). Incidence of complications was similar to the CBS-W group. Subanalysis showed a shorter time-to-LA in the CBS-N versus CBS-W group, 72 ± 46 seconds versus 293 ± 180 seconds, P < .001. CONCLUSIONS: Our study showed that the CBS-N technique is feasible and safe under echocardiographic guidance. Without sheath exchange, it simplifies the CB2 procedure, is less costly, time sparing, and might reduce the risk of air embolism.

Predictors of long-term outcome in patients undergoing a first repeat ablation consisting solely of re-isolation of reconnected pulmonary veins.

AIMS: To define predictors of long-term outcome of a first repeat ablation solely consisting of re-isolation of reconnected pulmonary veins (PVs). METHODS: Three hundred seven patients (age 59 ± 9%, 77% males, non-paroxysmal AF 43%) with recurrent AF after first PVI were studied. Re-isolation of reconnected PVs was guided by a circular mapping catheter and 3D mapping system using RF ablations. A PV was defined as "triggering" in case of spontaneous ectopy or AF paroxysms originating from the PV. RESULTS: After a mean follow-up of 5.05 ± 2.21 years, 194 (63.2%) patients (73.0% in PAF vs 50.4% in non-PAF, log Rank <0.001) were free from AF. A "triggering" PV was present in 48 (15.6%) during the first PVI and in 52 (16.9%) at repeat. Independent predictors of recurrence were a non-PAF type (HR: 1.814, 95%CI: 1.090 - 3.018, p=0.022) and early recurrence (≤ 3 months) after first PVI (HR: 1.632, 95%CI: 1.091 - 2.443, p=0.017) while a "triggering" PV at first or repeat was a predictor of good outcome (HR: 0.574; 95%CI: 0.344 - 0.959; p=0.034) in the multivariable analysis. CONCLUSIONS: A repeat ablation solely consisting of re-isolation of reconnected PVs results in a high degree of long-term AF freedom, especially in PAF and in case of a PV trigger at index or repeat. Patients with non-PAF or experiencing early AF recurrence after first PVI are less responsive.

Impact of cryoballoon-guided pulmonary vein isolation on non-invasive autonomic tests in patients with paroxysmal atrial fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) modulates the intrinsic cardiac autonomic nervous system (ANS). We evaluated the impact of PVI on 5 non-invasive autonomic tests. METHODS: Thirty patients (76% male, mean age 60.37 ±â€¯9.02 years) with paroxysmal atrial fibrillation (AF) underwent cryoballoon-guided PVI. Five autonomic tests were performed 24hrs before and after PVI (N = 30) and repeated after 6months (N = 22). Parasympathetic function was measured by heart rate (HR) variability during deep breathing (E/I ratio, I-E difference), Valsalva maneuver (Valsalva-ratio) and head-up tilt test (30/15 ratio). Sympathetic function was measured by systolic BP response to sustained handgrip and 10' tilting and by diastolic BP response to cold water. RESULTS: 24hrs after PVI, baseline HR increased from 57.93 ±â€¯9.06 bpm to 71.10 ±â€¯12.75 bpm (p < 0.001). At 6 months, baseline HR was lower than immediately post-PVI (62.59 ±â€¯7.89 vs 71.36 ±â€¯13.58 bpm, p = 0.032) but still higher in comparison to pre-PVI (62.59 ±â€¯7.89 vs 57.09 ±â€¯8.80 bpm, p < 0.001). No differences were seen in baseline BP and parasympathetic tests acutely and at 6months. Besides an acute lowering in systolic BP increase during handgrip test, all sympathetic tests remained unchanged. CONCLUSIONS: An acute HR increase attenuated at 6months and an acute lowered systolic BP response to sustained handgrip were the only changes after cryoballoon-guided PVI. Non-invasive autonomic tests seem therefore not appropriate to evaluate the autonomic modulatory effect of PVI, either due to a too limited sensitivity or a too localized effect of PVI to influence test results.

Value of ultrasound for access guidance and detection of subclinical vascular complications in the setting of atrial fibrillation cryoballoon ablation.

AIMS: Vascular complications are the most common complications of atrial fibrillation (AF) ablation. Cryoballoon (CB) ablation for AF needs the insertion of a large 15 Fr sheath in the femoral vein. Our aim was to investigate the impact of vascular ultrasound (US) in guiding access and evaluating post-procedural subclinical complications in a large, multi-centre patient cohort that underwent CB ablation. METHODS AND RESULTS: A total cohort of 1435 consecutive patients were subdivided in 870 US -/-, 265 US -/+, and 300 US +/+ patients depending on US performance for: venipuncture guidance/post-procedural evaluation. Major clinical complications (requiring intervention and/or prolonged stay) were assessed. Irrespective of the clinical status, major US events were systematically determined in the subgroups with US evaluation 1 day post-procedure, if evidence of inadvertent artery puncture/cannulation (communication between artery and collection or artery-vein, regardless of the thrombosis state). Major clinical events were encountered in 1.7% (15/870), 1.1% (3/265), and 0% of patients in US -/-, US -/+, and US +/+ group, respectively (P = 0.02 between US -/- and US +/+ group). In the US -/- group, 5/10 (50%) of pseudo-aneurysms were diagnosed during readmission after a mean of 24 ± 11 days post-procedure. No delayed presentation was seen in the US -/+ group. Major US events during the US protocol post-procedure were seen in 3.8% (10/265) vs. 0.3% (1/300) of patients in US -/+ vs. US +/+ group, respectively, P = 0.004. CONCLUSION: US-guided venipuncture was associated with a near-to-zero risk of vascular complications in our patients undergoing CB ablation.

Atrial fibrillation ablation with the second generation cryoballoon: Multicenter propensity score matched comparison between freezing strategies.

BACKGROUND: Second generation cryoballoon (CB-A) ablation is highly effective in achieving pulmonary vein (PV) isolation and freedom from atrial fibrillation (AF). However, the ideal freezing strategy is still under debate. Our objective was to investigate the efficacy and outcome between different freezing strategies used with the CB-A in a multicenter, matched population. METHODS: From a total cohort of 1018 patients having undergone CB-A ablation for drug-refractory AF, 673 patients with follow-up ≥6months were included and stratified according to the applied freezing strategy: bonus freeze (BF) versus single freeze (SF). Final population of 256 BF patients was compared with 256 propensity-score matched SF patients. RESULTS: BF strategy consisted of 3 different protocols: 3cycles of 180s; 2cycles of 240s; and cycles of 240s followed by 180s in 99/256 (39%); 42/256 (16%); and 115/256 (45%) patients, respectively. SF approach included cycles of 240s in 23/256 (9%), and 180s in 233/256 (91%) patients. Electrical isolation could be achieved in all PVs by both protocols, with shorter procedure and fluoroscopy times in the SF group (mean 106 vs 65min, and 18 vs 14min, respectively, P<0.001). Phrenic nerve palsy persisted after discharge in a total of 11 patients (2.1%): 4 (1.6%) in the BF group vs 7 (2.7%) in the SF group, P=0.5. AF-free survival was similar between the 2 groups during follow-up (mean 18±10months) (log rank, P=0.6). CONCLUSIONS: CB-A ablation showed equal efficacy and outcome between SF and BF strategy.

Complications of pulmonary vein isolation in atrial fibrillation: predictors and comparison between four different ablation techniques: Results from the MIddelheim PVI-registry.

Aims: To define predictors of complications of pulmonary vein isolation (PVI) and compare safety between different ablation techniques. Methods and results: One thousand patients with atrial fibrillation (AF) (age 60 ± 10, 72% males, CHA2DS2-VASc score 1 ± 1) underwent PVI using various techniques: conventional PVI (CPVI) using mapping with irrigated point-per-point RF ablation (n = 576), multi-electrode RF ablation with the pulmonary vein ablation catheter (PVAC) (n = 272) or high density mesh ablator (HDMA) (n = 59) and cryoballoon (CB) ablation (n = 93). A complication was defined as any procedure-related adverse event resulting in permanent injury or death, requiring intervention or treatment, or prolonging/requiring hospitalization for >48 h. A total of 105 (10.5%) complications occurred in 101 (10.1%) patients. No periprocedural death occurred. Most frequent complications were vascular complications (4%) and pericarditis (3.1%). Seven patients experienced permanent deficit due to PV stenosis (n = 3, 1 CPVI, 2 PVAC) (n = 3) and phrenic nerve palsy (PNP) (n = 4, 3 CPVI, 1 PVAC). Independent predictors of complications were female sex [odds ratio (OR) = 1.73; 95% confidence interval (CI) 1.08-2.79; P = 0.023], CHA2DS2-VASc score (OR = 1.24; 95% CI 1.01-1.52; P = 0.039), and ablation technique (P = 0.006) in multivariable-adjusted analysis. Among the different techniques, CB (P = 0.047) and PVAC ablation (P = 0.003) had lowest overall complication rates. Complication profile (type/severity) differed between techniques (association between CB and PNP, CPVI and pericardial injury, PVAC and transient ischaemic attack/PV stenosis). Conclusion: Overall complication rate of PVI with various techniques is 10.5%. Permanent deficit occurred only after PVAC and CPVI in 0.7% of patients. Female sex and a higher CHA2DS2-VASc score increase, while PVAC and CB-PVI decrease, overall risk. Differences in overall safety and individual complication profile make selection of the ablation technique in relation to clinical risk profile possible.

MAGNETIC VT study: a prospective, multicenter, post-market randomized controlled trial comparing VT ablation outcomes using remote magnetic navigation-guided substrate mapping and ablation versus manual approach in a low LVEF population.

PURPOSE: Patients with ischemic cardiomyopathy (ICM) are prone to scar-related ventricular tachycardia (VT). The success of VT ablation depends on accurate arrhythmogenic substrate localization, followed by optimal delivery of energy provided by constant electrode-tissue contact. Current manual and remote magnetic navigation (RMN)-guided ablation strategies aim to identify a reentry circuit and to target a critical isthmus through activation and entrainment mapping during ongoing tachycardia. The MAGNETIC VT trial will assess if VT ablation using the Niobe™ ES magnetic navigation system results in superior outcomes compared to a manual approach in subjects with ischemic scar VT and low ejection fraction. METHODS AND RESULTS: This is a randomized, single-blind, prospective, multicenter post-market study. A total of 386 subjects (193 per group) will be enrolled and randomized 1:1 between treatment with the Niobe ES system and treatment via a manual procedure at up to 20 sites. The study population will consist of patients with ischemic cardiomyopathy with left ventricular ejection fraction (LVEF) of ≤35% and implantable cardioverter defibrillator (ICD) who have sustained monomorphic VT. The primary study endpoint is freedom from any recurrence of VT through 12 months. The secondary endpoints are acute success; freedom from any VT at 1 year in a large-scar subpopulation; procedure-related major adverse events; and mortality rate through 12-month follow-up. Follow-up will consist of visits at 3, 6, 9, and 12 months, all of which will include ICD interrogation. CONCLUSIONS: The MAGNETIC VT trial will help determine whether substrate-based ablation of VT with RMN has clinical advantages over manual catheter manipulation. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02637947.

Vdrive Evaluation of Remote Steering and Testing in Lasso Electrophysiology Procedures Study: The VERSATILE Study in Atrial Fibrillation Ablation.

INTRODUCTION: Circular mapping catheters (CMC) are an essential tool in most atrial fibrillation ablation procedures. The Vdrive™ with V-Loop™ system enables a physician to remotely manipulate a CMC during electrophysiology studies. Our aim was to compare the clinical performance of the system to conventional CMC navigation according to efficiency and safety endpoints. METHODS AND RESULTS: A total of 120 patients scheduled to undergo a CMC study followed by pulmonary vein isolation (PVI) were included. Treatment allocation was randomized 2:1, remote navigation:manual navigation. The primary effectiveness endpoint was assessed based on both successful navigation to the targeted pulmonary vein (PV) and successful recording of PV electrograms. All PVs were treated independently within and between patients. The primary safety endpoint was assessed based on the occurrence of major adverse events (MAEs) through seven days after the study procedure. Primary effectiveness endpoints were achieved in 295/302 PVs in the Vdrive arm (97.7%) and 167/167 PVs in the manual arm (100%). Effectiveness analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0405; δ = -0.05) per the Cochran-Mantel-Haenszel test adjusted for PV correlation. Five MAEs related to the ablation procedure occurred (three in the Vdrive arm-3.9%; two in the manual arm-2.33%). No device-related MAEs were observed; safety analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0441; δ = 0.07) per the normal Z test. CONCLUSION: Remote navigation of a CMC is equivalent to manual in PVI in terms of safety and effectiveness. This allows for single-operator procedures in conjunction with a magnetically guided ablation catheter.

The presence of extensive atrial scars hinders the differential diagnosis of focal or macroreentrant atrial tachycardias in patients with complex congenital heart disease.

AIMS: Atrial tachycardias (ATs) frequently develop in patients with congenital heart defects (CHDs). This study aimed to evaluate the effects of extensive atrial scar formation on the total atrial activation time (TAAT) and its relation to the tachycardia cycle length (CL) to classify AT. METHODS AND RESULTS: Seventy-one patients were included and divided into two groups: patients without CHD (Group I, 35 patients) and with CHD (Group II, 36 patients). All patients underwent CARTO electroanatomical activation mapping. Two subgroups were created: centrifugal (CAT) or macroreentrant AT (MRAT). Total atrial activation time, CL, and mean bipolar signal amplitude (BiSA) were analysed. In Group I, 18 patients (51.4%) had CAT and 17 (48.6%) MRAT. The mean BiSA for Group I was 1.30 ± 0.32 mV. Total atrial activation time/CL ratios were different between CAT and MRAT (28.4 ± 16.9 vs. 66.6 ± 14.3%, P < 0.001). In Group II, 18 patients (50%) had CAT and 18 patients (50%) MRAT. The mean BiSA was 0.94 ± 0.50 mV and was not different for CAT and MRAT subgroups (1.04 ± 0.64 vs. 0.85 ± 0.29, P = 0.243). Total atrial activation time/CL ratios were comparable between CAT and MRAT patients (69.0 ± 40.4 vs. 83.6 ± 8.3%, P = 0.243). A significant lower BiSA was found for CAT with TAAT/CL ratios above 40% (0.62 ± 0.11 vs. 1.90 ± 0.18 mV, P < 0.001). A strong negative correlation was identified between the BiSA and the TAAT/CL ratio in patients with CAT in Group II (-0.742; P < 0.001). CONCLUSION: Low mean BiSA values in CHD patients are associated with altered impulse propagation, making TAAT- and CL-based diagnostic tools inaccurate. Further diagnostic tests are needed to determine the correct mechanism of ATs.

Impact of radiofrequency characteristics on acute pulmonary vein reconnection and clinical outcome after PVAC ablation.

OBJECTIVE: The objective was to study the impact of radiofrequency (RF) characteristics on acute pulmonary vein reconnection (PVR) and outcome after PVAC ablation. PVI with additional ablation of PVR (PVI + PVR) was compared to PVI-only. METHODS: In 40 consecutive patients, after PVAC-guided PVI, adenosine and a 1-hour waiting time were used to unmask and ablate acute PVR (PVI + PVR group). RF-characteristics and 1-year AF freedom were compared post hoc to 40 clinically matched patients undergoing PVI only (PVI-only group). Custom-made software was used to assess RF characteristics of the PVAC applications needed to obtain baseline PVI. RESULTS: There was no difference in clinical characteristics or baseline RF-profile between both groups. Acute PVR was observed and ablated in 38 of 160 veins (24%). AF-freedom after PVI + PVR was higher than PVI (85% vs 65%, P < 0.05). Within the PVI group, comparing patients with and without AF-recurrence, the percentage of PVAC applications with high T° (>48°) but low power (<3W) was higher (28 ± 18% vs 11 ± 11%, P < 0.0001). Within the PVI + PVR group, when comparing PVs with and without PVR, the percentage of low power/high T° PVAC applications was also higher (27 ± 13% vs 13 ± 15%, P < 0.0001). CONCLUSIONS: (1) After PVAC ablation, 24% of PVs exhibit acute reconnection. Additional ablation of reconnection improves clinical outcome. (2) Acute reconnection as well as clinical recurrence of AF are characterized by PVAC ablation with a considerable number of applications with high temperature but low power. (3) If PV isolation is obtained with low power applications, a consistent use of both adenosine and waiting time is required.

Safety and feasibility of single-catheter ablation using remote magnetic navigation for treatment of slow-fast atrioventricular nodal reentrant tachycardia compared to conventional ablation strategies.

OBJECTIVE: Ablation of atrioventricular nodal re-entrant tachycardia (AVNRT) is a highly effective procedure both with radiofrequency (RF) and cryoenergy (CE). Conventionally, it requires several diagnostic catheters and hospital admission. This study assessed the safety and efficacy of a highly simplified approach using the magnetic navigation system (MNS) compared to CE and manual RF ablation (MAN). METHODS AND RESULTS: In the MNS group a single magnetic-guided quadripolar catheter was inserted through the internal jugular vein to perform ablation. In the CE group cryomapping preceded ablation and for MAN procedures conventional ablation was performed. The following parameters were analysed: success- and recurrence rate, procedure-, fluoroscopy- and total application time. In total 69 eligible patients were treated with MNS (n = 26), CE (n = 25) and MAN (n = 16). The success rates were 100%, 100% and 94%, respectively (p = ns). The mean procedural time was 83 +/- 25 min for MNS, 117 +/- 47 min for CE and 117 +/- 55 min for MAN (P < 0.01). Total radiation time was significantly lower for MNS [0.0 min (IQR 0.0-0.0)] compared to CE [15.1 min (IQR 9.1-23.8), P < 0.001] and MAN [17.5 min (IQR 7.0-31.3), P < 0.001]. The total application time was comparable for both RF groups: 357 +/- 315 s (MNS) vs 204 +/- 177 s (MAN) (P = 0.14). No major adverse events occurred. After 3 months follow-up similar PR intervals were recorded for all patients. During a follow-up of 26 +/- 5 months recurrence rates were 3.8%, 4.0% and 6.3%, respectively, for each group. CONCLUSIONS: The MNS-guided single-catheter approach is a feasible and safe technique for the treatment of patients with typical AVNRT.

Prevalence of atrial fibrillation in adults participating in a large-scale voluntary screening programme in Belgium.

OBJECTIVE: Atrial fibrillation (AF) is a common arrhythmia in clinical practice. AF fulfils many of the criteria for a screening programme. No data about the prevalence of AF in non-hospitalized patients are available in Belgium. The aim of the study was to assess feasibility and effectiveness of a nationwide-organized voluntary screening programme in the general population in Belgium. METHODS: A total of 13.564 participants were screened, of whom 10,758 were older than 40 years (GSP group). Participants filled in stroke risk stratification questionnaires (CHADS2 and CHA2DS2-VASc). A one-lead electrocardiogram was performed. RESULTS: 228 participants had AF at the time of screening (AF group), with 125 women and 103 men (i.e., 1.9% and 2.6% of total women and men), representing a prevalence of 2.2% (95% CI 1.3% and 3.0%) of the screened population. Age of the AF group was 67 +/- 12 y (range 40-87 y). Using the CHADS2-score, 58% of participants with a positive AF screening had a high risk score, and 21% had an intermediate risk score. Using the CHA2DS2-VASc-score, 72% of the participants had a high risk score, and 21% had an intermediate risk score. CONCLUSION: AF was present in 2.2% of the respondents. At least 60% of AF group had an increased risk for thrombo-embolism. Although substantial methodological issues limit the exact interpretation of these results, the present study shows that a volunatry screening programme with a simple screening protocol is able to detect an important number of patients with previously undetected AF.