Cardioneuroablation for vasovagal syncope: insights on patients' selection, centre settings, procedural workflow and endpoints-results from an European Heart Rhythm Association survey.

AIMS: Cardioneuroablation (CNA) is a catheter-based intervention for recurrent vasovagal syncope (VVS) that consists in the modulation of the parasympathetic cardiac autonomic nervous system. This survey aims to provide a comprehensive overview of current CNA utilization in Europe. METHODS AND RESULTS: A total of 202 participants from 40 different countries replied to the survey. Half of the respondents have performed a CNA during the last 12 months, reflecting that it is considered a treatment option of a subset of patients. Seventy-one per cent of respondents adopt an approach targeting ganglionated plexuses (GPs) systematically in both the right atrium (RA) and left atrium (LA). The second most common strategy (16%) involves LA GP ablation only after no response following RA ablation. The procedural endpoint is frequently an increase in heart rate. Ganglionated plexus localization predominantly relies on an anatomical approach (90%) and electrogram analysis (59%). Less utilized methods include pre-procedural imaging (20%), high-frequency stimulation (17%), and spectral analysis (10%). Post-CNA, anticoagulation or antiplatelet therapy is prescribed, with only 11% of the respondents discharging patients without such medication. Cardioneuroablation is perceived as effective (80% of respondents) and safe (71% estimated <1% rate of procedure-related complications). Half view CNA emerging as a first-line therapy in the near future. CONCLUSION: This survey offers a snapshot of the current implementation of CNA in Europe. The results show high expectations for the future of CNA, but important heterogeneity exists regarding indications, procedural workflow, and endpoints of CNA. Ongoing efforts are essential to standardize procedural protocols and peri-procedural patient management.

A worldwide survey on incidence, management, and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: the POTTER-AF study.

AIMS: Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management, and outcome are sparse. METHODS AND RESULTS: This international multicentre registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553 729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed, at 214 centres in 35 countries. In 78 centres 138 patients [0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (P < 0.0001)] were diagnosed with an oesophageal fistula. Peri-procedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8% and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) [odds ratio 7.463 (2.414, 23.072) P < 0.001]. CONCLUSION: Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high.

Major incidental findings on routine cardiovascular magnetic resonance imaging prior to first-time catheter ablation of atrial fibrillation.

INTRODUCTION: Preprocedural cardiovascular magnetic resonance (CMR) or computed tomography (CT) imaging of the left atrium/pulmonary veins is usually employed to guide catheter ablation of atrial fibrillation (AFCA). Incidental findings (IFs) are common on cardiac imaging prior to AFCA. However, previous studies have mainly focused on extracardiac IFs detected on CT scan. We aimed to assess the prevalence of relevant cardiac and extracardiac IFs on routine preprocedural CMR in a large patient cohort scheduled for first-time AFCA and report its impact on clinical decision-making and management. METHODS AND RESULTS: We included 2000 consecutive patients (62 ± 10 years; 59% male) who underwent CMR prior to first-time AFCA between April 2015 and March 2019. Among these patients 172 (8.6%) had a total of 184 major IFs. Detection of major IFs resulted in cancellation of the scheduled AFCA procedure in 88 patients (4.4%). Forty-two patients (2.1%) have never been ablated, 46 (2.3%) underwent postponed AFCA after a median time of 83 (32-213) days. The remaining 84 patients (4.2%) underwent an individualized approach to AFCA. The most common major IFs were accessory or anomalous PVs in 76 (3.8%), extracardiac abnormalities suspicious of malignancy in 29 (1.5%), and positive stress perfusion imaging in 19 (7.2% of 261 tested) patients. In 19 patients (1.0%) preprocedural CMR provided the diagnosis of a previously unknown structural cardiac disease. CONCLUSIONS: Unexpected relevant findings on routine preprocedural CMR affected clinical decision-making and management in 8.6% of patients scheduled for first-time AFCA. However, whether preprocedural CMR imaging may improve overall clinical outcome needs to be addressed in future research.

Characteristics of left atrial remodeling in patients with atrial fibrillation and hypertrophic cardiomyopathy in comparison to patients without hypertrophy.

Atrial fibrillation (AF) leads to remodeling characterized by changes in both size and shape of the left atrium (LA). Here we aimed to study the effect of hypertrophic cardiomyopathy (HCM) on the pattern of LA remodeling in AF-patients. HCM-patients (n = 23) undergoing AF ablation (2009-2012) were matched and compared with 125 Non-HCM patients from our prospective registry. Pre-procedural CT data were analyzed (EnSite Verismo, SJM, MN) to determine the maximal sagittal (anterior-posterior, AP), coronal (superior-inferior, SI and transversal, TV) dimensions and the sphericity index (LAS). Volume (LAV) was rendered after appendage (LAA) and pulmonary vein (PV) exclusion. A cutting plane, between PV ostia/LAA and parallel to the posterior wall, divided LAV into anterior- (LA-A) and posterior-LA (LA-P) parts. The ratio LA-A/LAV was defined as asymmetry index (ASI). HCM patients had a wider inter-ventricular septum and a smaller LV than Non-HCM patients. LA volume (LAV 166 ± 72 vs. 130 ± 36 ml, p = 0.03) and LA diameters were significantly larger in HCM patients. Anterior volume (LA-A: 112 ± 48 vs. 83 ± 26 ml, p < 0.001) differed significantly between groups, whereas the posterior volume LA-P (55 ± 28 vs. 47 ± 13 ml, p = 0.23) and LAS (75% vs. 78%, p = 0.089) was similar in both groups. As a result, ASI was significantly higher (67 ± 6 vs. 63 ± 6%, p = 0.01) in HCM than in Non-HCM patients. In conclusion, LA remodeling in patients with AF and HCM is characterized by asymmetric dilatation, driven by an anterior rather than a posterior dilatation. This can be characterized by three-dimensional imaging and could be used as surrogate of advanced atrial remodeling.

[Bradycardia in pregnancy : Case report and review of the literature]. / Bradykardie in der Schwangerschaft : Fallbericht und Blick auf die Literatur.

We report the case of a pregnant woman with complete heart block during her first trimester who presented with dyspnea at the East African Heart Rhythm Project in Nairobi. There was no evidence of an acute cause (e.g., myocarditis, cardiomyopathy, autoimmune or neuromuscular disease). No ECG had been previously documented; therefore, congenital complete heart block was likely. We implanted a dual-chamber pacemaker using conventional fluoroscopy. Several measures at implantation allowed us to limit fluoroscopy to 30 s and radiation to < 100 µGym2. The implantation was uneventful, dyspnea improved instantaneously and further pregnancy, labor and birth were uncomplicated. Bradycardia requiring pacemaker implantation is rare during pregnancy and usually consists of symptomatic complete heart block. Beyond undiagnosed or untreated pre-existing atrioventricular block, drug therapy for fetal tachycardia, myocarditis (including Lyme borreliosis and Chagas disease), inflammatory infiltrative diseases (e.g., sarcoidosis), cardiomyopathies and neuromuscular disease may have caused bradycardia. In the absence of treatable causes, pacemaker implantation becomes necessary if bradycardia brings about risks for the mother or the fetus. Using transesophageal or intracardiac echocardiography, radiation can be avoided completely or, by taking some simple measures, may be kept to a minimum so that there is no risk for the fetus.

Association of low-voltage areas with the regional wall deformation and the left atrial shape in patients with atrial fibrillation: A proof of concept study.

BACKGROUND: Left atrium (LA) remodeling is associated with atrial fibrillation (AF) and reduced success after AF ablation, but its relation with low-voltage areas (LVA) is not known. This study aimed to evaluate the relation between regional LA changes and LVAs in AF patients. METHODS: Pre-interventional CT data of patients (n = 24) with LA-LVA (<0.5 mV) in voltage mapping after AF ablation were analyzed (Surgery Explorer, QuantMD LLC). To quantify asymmetry (ASI = LA-A/LAV) a cutting plane parallel to the rear wall and along the pulmonary veins divided the LA-volume (LAV) into anterior (LA-A) and posterior parts. To quantify sphericity (LAS = 1-R/S), a patient-specific best-fit LA sphere was created. The average radius (R) and the mean deviation (S) from this sphere were calculated. The average local deviation (D) was measured for the roof, posterior, septum, inferior septum, inferior-posterior and lateral walls. RESULTS: The roof, posterior and septal regions had negative local deviations. There was a correlation between roof and septum (r = 0.42, p = 0.04), lateral and inferior-posterior (r = 0.48, p = 0.02) as well as posterior and inferior-septal deviations (r = -0.41, p = 0.046). ASI correlated with septum deformation (r = -0.43, p = 0.04). LAS correlated with dilatation (LAV, r = 0.49, p = 0.02), roof (r = 0.52, p = 0.009) and posterior deformation (r = -0.56, p = 0.005). Extended LVA correlated with local deformation of all LA walls, except the roof and the septum. LVA association with LAV, ASI and LAS did not reach statistical significance. CONCLUSION: Extended LVA correlates with local wall deformations better than other remodeling surrogates. Therefore, their calculation could help predict LVA presence and deserve further evaluation in clinical studies.

Clinical utility of cardiovascular magnetic resonance imaging in patients with implantable cardioverter defibrillators presenting with electrical instability or worsening heart failure symptoms.

BACKGROUND: Data on the usefulness of cardiovascular magnetic resonance (CMR) imaging for clinical decision making in patients with an implanted cardioverter defibrillator (ICD) are scarce. The present study determined the impact of CMR imaging on diagnostic stratification and treatment decisions in ICD patients presenting with electrical instability or progressive heart failure symptoms. METHODS: 212 consecutive ICD patients underwent 1.5 T CMR combining diagnostic imaging modules tailored to the individual clinical indication (ventricular function assessment, myocardial tissue characterization, adenosine stress-perfusion, 3D-contrast-enhanced angiography); four CMR examinations (4/212, 2%) were excluded due to non-diagnostic CMR image quality. The resultant change in diagnosis or clinical management was determined in the overall population and compared between ICD patients for primary (115/208, 55%) or secondary prevention (93/208, 45%). Referral indication consisted of documented ventricular tachycardia, inadequate device therapy or progressive heart failure symptoms. RESULTS: Overall, CMR imaging data changed diagnosis in 40% (83/208) with a significant difference between primary versus secondary prevention ICD patients (37/115, 32% versus 46/93, 49%, respectively; p = 0.01). The information gain from CMR led to an overall change in treatment in 21% (43/208) with a similar distribution in primary versus secondary prevention ICD patients (25/115,22% versus 18/93,19%, p = 0.67). The effect on treatment change was highest in patients initially scheduled for ventricular tachycardia ablation procedure (18/141, 13%) with revision of the treatment plan to medical therapy or coronary revascularization. CONCLUSIONS: CMR imaging in ICD patients presenting with electrical instability or worsening heart failure symptoms provided diagnostic or management-changing information in a considerable proportion (40% and 21%, respectively).

Effect of Exercise on Outcome after Ventricular Tachycardia Ablation in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy.

Competitive sports and intensive exercise are associated with adverse outcomes in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). This study aimed to assess the role of exercise on long-term results of radiofrequency catheter ablation (RFCA) therapy of ventricular tachycardia (VT) in patients with ARVD/C. Exercise participation was evaluated by telephone or in-person interviews in patients from our ARVD/C registry with previous VT ablation (38 patients, 26 males, age 52.6±14.1years). Of 38 patients, 30 were involved in sports activities before RFCA. Only the minority of our patient population (21.1%) had a sedentary lifestyle before RFCA; 42.1 and 36.8% reported recreational or competitive sports, respectively. During the follow-up period of 52.5±31.4 months, 23 of the total 38 patients with previous RFCA (60.5%) remained free from VT recurrence. In univariate and binary logistic regression analysis, only advanced age was significantly associated with VT recurrence, with a hazard ratio of 1.15, and 95% confidence interval 1.05-1.26 (p=0.004). The results of our observational study indicate that recreational sports do not impair long-term results after RFCA treatment compared with a sedentary lifestyle. Furthermore, the dynamic component of recreational exercise did not affect the outcome of VT ablation in our patient population. Recreational exercise at low to moderate intensity is not associated with an increased risk for VT recurrence after catheter ablation in patients with ARVD/C.

Exercise-related sudden cardiac death of an American football player with arrhythmogenic right ventricular dysplasia/cardiomyopathy AND sarcoidosis.

This case emphasizes the value of cardiac MRI and genetic testing in the early phase of ARVD/C. It also emphasizes the increased risk of SCD for patients with ARVD/C participating in competitive sports, even with immediate cardiopulmonary resuscitation.

Catheter ablation of atrial fibrillation with nonfluoroscopic catheter visualization-a prospective randomized comparison.

PURPOSE: The application of a novel platform for nonfluoroscopic catheter sensor tracking within pre-recorded x-ray loops in the context of catheter ablation of atrial fibrillation (AF) demonstrated significant potential for reduction of fluoroscopy. We sought to provide the first prospective randomized comparison of fluoroscopy needs, procedure times, and complications in AF catheter ablation with or without additional use of nonfluoroscopic catheter visualization (NFCV). METHODS: Patients with AF were randomized into two groups before scheduled radiofrequency ablation: (1) using established mapping systems and fluoroscopy as needed (CONV group) or (2) with additional NFCV (NFCV group). All procedures were performed in the same lab using the same ablation catheter tip technology and the same mapping and ablation strategies. Primary endpoints were radiation time and dose. Secondary endpoints were procedural parameters, complications, and long-term success. RESULTS: A total of 80 patients (48 male patients, mean age 60 years, 46 patients with paroxysmal AF) were randomized into the two groups. Clinical parameters between both groups were similar. NFCV use reduced mean fluoroscopy time (1.9 vs. 13.2 min, p < 0.001) and mean dose (510 vs. 1549 Gycm2, p < 0.001) significantly. Procedural parameters were similar in the two groups. One conservatively treated groin complication occurred (1.3%). CONCLUSIONS: Radiation exposure can be significantly reduced by using the novel NFCV technology in addition to standard AF ablation technologies without negative effects on procedure durations, success rates, or complication rates. With the use of the technology, abandonment of lead protection for EP staff is possible following transseptal puncture.

The Diagnosis and Treatment of Pacemaker-Associated Infection.

BACKGROUND: Approximately 105 000 cardiac electronic devices are newly implanted in Germany each year. Germany has the highest implantation rate with respect to population of any European country. Infections in cardiac implants are serious complications, with an associated in-hospital mortality of 5-15%. It is thus very important to optimize the diagnostic and therapeutic strategies by which such infections can be detected early and treated effectively. METHODS: This review is based on pertinent publications retrieved by a search in PubMed, with special attention to the current recommendations of international medical specialty societies. RESULTS: According to the international literature, the incidence of device-associated infection is 1.7% (in six months) for implanted defibrillators and 9.5% (in two years) for resynchronization devices. No absolute figures on infection rates are available for Germany. Infection can involve either the site where the impulse generator is implanted or the intravascular portion of the electrodes. The most important elements of the diagnostic evaluation are: assessment of the local findings; pathogen identification by culture of peripheral blood, swabs of the infected site, or material recovered at surgery; and transesophageal echocardiography to detect endocarditic deposits on the electrodes or cardiac valves. The treatment consists of appropriate antibiotic administration and the complete removal of all foreign material. These special extractions are generally performed via the transvenous route. With the aid of various sheath systems, the procedure can be carried out safely and effectively, with a success rate above 95% and a complication rate below 3%. The indications for the implantation of a new device after eradication of the infection should be critically reassessed. CONCLUSION: Untreated infection carries a high mortality. Evaluation and treatment according to a standardized clinical algorithm facilitate correct and timely diagnosis and the choice of an appropriate therapeutic strategy.

Safety profile of near-zero fluoroscopy atrial fibrillation ablation with non-fluoroscopic catheter visualization: experience from 1000 consecutive procedures.

Aims: Efforts to reduce radiation exposure during catheter ablation procedures have included the use of various technological measures. Significant results have been achieved to the point where near lead-free procedures in routine clinical practice has become a realistic goal. The integration of MediGuide technology [non-fluoroscopic catheter visualization technology (NFCV)] and three-dimensional electroanatomical mapping is one of the methods developed in response to radiation reduction initiatives. We aimed to evaluate the impact of this NFCV technology on atrial fibrillation (AF) catheter ablation in terms of reduction in procedural and radiation time as well as safety aspects. Methods and results: Between March 2012 and March 2017, a total of 1000 patients underwent AF ablation using NFCV. Patient and procedural data and complications within the first 3 months were entered into a prospective registry and analysed. We assessed procedure time, fluoroscopy time, and dose and complications. In a cohort of 1000 patients (62.9 ± 11 years; 72% men; left ventricular ejection fraction 57%; and left atrial diameter 43.2 mm), the median procedure time was 120 min, median fluoroscopy time was 0.90 min, and the median fluoroscopy dose of was 345.1 cGy · cm2. Stratification of the first (Group 1) and the last 250 (Group 2) cases showed significant improvement in the median procedure time (140-110 min) and reduction in the median fluoroscopy time (6-0.5 min) and the median dose (2263-151.9 cGy · cm2). The overall complication rate was 2.0%. Conclusion: The use of NFCV technology enables safe, consistent, and 'near lead-free' performance of AF ablation in routine clinical practice.

Supraventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy associate with long-term outcome after catheter ablation of ventricular tachycardias.

Aims: This study aimed to assess the impact of supraventricular tachycardia (SVT) on long-term results of radiofrequency catheter ablation therapy of ventricular tachycardia (VT) in a large cohort of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Methods and results: Supraventricular tachycardia occurrence has been studied in patients from our ARVD/C registry (70 patients, 48 male, age 53.2 ± 14.0, 45 patients (64.3%) with previous VT ablation). SVT were diagnosed in 26 of 70 patients (37.1%). Atrial fibrillation (AF) was the most frequent atrial arrhythmia, diagnosed in 17 patients (24.3%). In univariate analysis advanced age, clinical symptoms of heart failure, enlarged right atrium, diagnosis of significant tricuspid regurgitation (TR), and inappropriate implantable cardioverters-defibrillators therapy were associated with SVT. In binary logistic regression analysis only heart failure: hazard ratio (HR) 10.89, 95% confidence interval (95% CI) 1.08-109.96 (P = 0.043) and significant TR: HR 4.79, 95% CI 1.35-16.33 (P = 0.015) remained associated with SVT. In patients with previous VT ablation Cox multiple regression survival analysis revealed older age (≥53 years): HR 4.63, 95% CI 1.51-14.24 (P = 0.008) and SVT: HR 3.01, 95% CI 1.15-7.89 (P = 0.025) as predictors for VT recurrence during the follow-up. Conclusion: SVT and older age are associated with the recurrence of VT after catheter ablation in patients with ARVD/C.

Myocardial voltage ratio in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

AIMS: This study aimed to analyze the influence of scar distribution between the endocardium and the epicardium in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). METHODS: Electroanatomical mapping data were derived from our ARVD/C registry. Myocardial voltage distribution between the endocardium and the epicardium was analyzed in 28 patients (18 men, 49.9 ± 13.0 years) with previous ventricular tachycardia (VT) ablation and complete right ventricular maps. RESULTS: During the follow-up period of 28 ± 22 months after ablation, 18 of 28 patients (64.3%) remained free from VT recurrence. In univariate analysis, five variables associated with VT recurrence, i. e., advanced age, right ventricular (RV) myocardial voltage ratio ≥0.58, inducibility of VT after ablation, and longer procedure and fluoroscopy time. In binary logistic regression analysis only RV myocardial voltage ratio ≥0.58 (hazard ratio 11.667, 95% confidence interval 1.487-91.543, p = 0.012) remained associated with an increased risk of VT recurrence. CONCLUSION: The myocardial voltage ratio (bipolar low voltage area/unipolar low voltage area) as a potential surrogate parameter for scar distribution between the endocardium and the epicardium is significantly associated with the outcome after VT ablation in ARVD/C.

Should all patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy undergo epicardial catheter ablation?

BACKGROUND: Epicardial radiofrequency catheter ablation is currently considered as the therapeutic option of choice in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) and recurrent ventricular tachycardia (VT). We hypothesised that inducibility of VT may guide the ablation strategy and thereby affect long-term results. Additional epicardial ablation was only performed if VT were still inducible after thorough endocardial ablation. METHODS: The objective was to examine an inducibility-guided ablation approach by comparing the long-term results between endocardial and epi-endocardial radiofrequency catheter ablation of VT in a large cohort of patients with ARVD/C. RESULTS: We studied from our ARVD/C registry (70 patients in total, 48 males, age 53.2 ± 14.0) 45 patients (64.3% of all patients) who underwent catheter ablation of VT. All patients received endocardial VT ablation. After endocardial ablation, 24 patients (53.3%) remained inducible. Additional epicardial ablation was performed in 22 patients (48.9%). After ablation, non-inducibility was achieved in overall 38 patients (84.4%). During a mean follow-up of 31.1 ± 27.4 months, 13 patients in each group (59.1% after endo- and epicardial ablation, 56.5% after endocardial ablation) remained free from VT recurrence (P = 0.862). CONCLUSIONS: An inducibility-guided catheter ablation strategy of VT in patients with ARVD/C prevents unnecessary epicardial ablation and may therefore be considered as an alternative to primary combined endo- and epicardial ablation.

[Brugada ECG]. / Das Brugada-EKG.

The Brugada syndrome (BrS) is characterized by a typical electrocardiogram (ECG) pattern of right precordial ST-segment elevation and the cardinal symptoms syncope and sudden cardiac death as clinical correlate of malignant ventricular arrhythmias in young adults without structural heart disease. The diagnosis of a type 1 Brugada-ECG is based on the documentation of a coved-type (≥ 0.2 mV) ST elevation followed by a negative T wave. The use of the ECG criteria postulated in the consensus of 2012 is helpful to distinguish between saddleback-type 2 (or type 3) J point/ST elevation and incomplete right bundle branch block. Spontaneous or drug-induced type 1 ST elevation can frequently only be detected in a single right precordial lead (V1 or V2), occurs sometimes together with a type 2 (or type 3) pattern in one and the same 12-lead ECG and can sometimes only be seen in modified right precordial leads. The ST elevation is less pronounced in females. Spontaneous and exercise-induced type 1 ST elevation, fragmented QRS complex, prolonged PR interval (> 200 ms), QRS prolongation in V2 (≥ 120 ms) and markers of an increased heterogeneity of ventricular repolarization are associated with an increased arrhythmic risk. The occurrence of spontaneous or dynamic type 1 ST elevation, a macroscopic T wave alternans or pronounced inferior (lateral) J point/ST elevation are signs of acute electrical instability.

Non-fluoroscopic catheter tracking for fluoroscopy reduction in interventional electrophysiology.

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that the application of this non-fluoroscopic catheter visualization system (NFCV) reduces fluoroscopy time and dose by 90-95% in a variety of electrophysiology (EP) procedures. This can be of relevance not only to the patients, but also to the nurses and physicians working in the EP lab. Furthermore, in a subset of indications such as supraventricular tachycardias, NFCV enables a fully non-fluoroscopic procedure and allows the lab staff to work without wearing lead aprons. With this protocol, we demonstrate that even complex procedures such as ablations of atrial fibrillation, that are typically associated with fluoroscopy times of >30 min in conventional settings, can safely be performed with a reduction of >90% in fluoroscopy exposure by the additional use of NFCV.

Ablation of typical atrial flutter using a non-fluoroscopic catheter tracking system vs. conventional fluoroscopy--results from a prospective randomized study.

AIMS: Reduction of radiation exposure using a sensor-based non-fluoroscopic catheter tracking (NFCT) system (MediGuide™, St Jude Medical, Inc.) was recently demonstrated by retrospective comparisons. We aimed to prospectively compare the effects of using NFCT vs. standard fluoroscopy on procedural parameters in patients undergoing radiofrequency ablation of typical atrial flutter. METHODS AND RESULTS: We prospectively randomized 40 patients undergoing cavotricuspid isthmus ablation for typical atrial flutter to either NFCT (n = 20) or conventional fluoroscopy (CONV, n = 20). Procedural parameters such as fluoroscopy time, radiation dose, and procedure duration, as well as periprocedural complications were compared. There were no statistically significant differences in baseline characteristics between the two groups. Bidirectional isthmus block was achieved in all patients. Fluoroscopy time was significantly reduced in the NFCT group {0.3 [inter-quartile range (IQR) 0.2; 0.48] min} when compared with CONV [5.7 (IQR 4.2; 11.5) min] (P < 0.001). This resulted in a significant reduction in radiation dose in patients randomized to NFCT [17.4 (IQR 11; 206.6) cGy cm(2)] vs. the CONV group [418.4 (IQR 277; 812.2) cGy cm(2)] (P < 0.001). There were no significant differences in procedure duration between the NFCT group [49.5 (IQR 37; 65) min] when compared with the CONV group [33.5 (IQR 26.3; 55.5) min] (P = 0.053). No adverse events were recorded. Freedom from atrial flutter at 6 months of follow-up was 19/20 (95%) in the NFCT and 18/20 (90%) in the CONV group (n.s.). CONCLUSION: In this first prospective randomized study, by comparing NFCT with standard fluoroscopy in patients undergoing radiofrequency ablation of typical atrial flutter, NFCT significantly reduced both radiation dose and fluoroscopy time with no effects on procedural duration. These findings support the incorporation of NFCT in routine clinical use.