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The Base of Pyramid markets in Sub-Saharan Africa face challenges such as poverty, poor infrastructure, illiteracy, and government corruption. This paper examines and presents an analytical review of the difficulties among consumers in Sub-Saharan Africa using academic institutions in Kenya to illustrate disruptive technology. Sub-Saharan Africa is faced with practical challenges with disruptive technology. Qualitative analysis is conducted among a sample from Kenya to assess the validity of challenges faced in academia. The authors use stratified sampling to select the local population and reach higher precision with a response rate of 85%. The qualitative analysis findings confirm a positive relationship between smart devices and network reliability, online teaching, online grade book, and virtual learning. The authors conclude that network reliability is the most challenging, especially for higher education institutions moving forward with adopting mobile learning. There exists a research gap in the literature on the Sub-Saharan Context. The challenges of disruptive technology and academia within Sub-Saharan Africa were limited to Kenya. Further research by practitioners and scholars can explore the challenges of disruptive technology in Sub-Saharan Africa.

This article explores the startup, growth, and success factors of Sinokrot Global Group. Sinokrot, a family-owned enterprise located in the Palestinian West Bank. Sinokrot began as a local confection in the West Bank, focusing on Agro-Industries and Agriculture, which has expanded into the global market. The firm employs permanent and seasonal workers from surrounding fifty villages and cities. It accounts for three thousand five hundred workers in Palestine society and ships to over twenty countries worldwide. Despite political and economic challenges in Palestine and the Middle East, Sinokrot has set modern successful business ventures in the Palestinian and other emerging markets. This case study on Sinokrot, now termed Sinokrot Holdings, examines factors that contributed to the success and survival of Sinokrot. A structured interview method is used to elicit relevant information from top management of Sinokrot on its sustainable growth and entry into global markets. We will discuss implications for entrepreneurs in less developed nations. An entrepreneurship success model for family-owned businesses is proposed.

Data about the safety of edoxaban in patients who underwent left atrial (LA) radiofrequency (RF) ablation procedures are lacking. This study sought to compare the safety of uninterrupted edoxaban with uninterrupted phenprocoumon administration during LA RF ablation for atrial fibrillation and atrial tachycardia. In total, 231 patients (mean age 64 ± 11years, male 71%) who underwent LA RF ablation under continuous oral anticoagulation (OAC) with edoxaban or phenprocoumon were included in the study. Patients on uninterrupted edoxaban (60 mg or 30 mg/day for at least 4 weeks) were matched for gender, age and type of arrhythmia with 2 patients on uninterrupted phenprocoumon (international normalized ratio 2 to 3). We identified 77 consecutive patients on edoxaban and n = 154 patients on phenprocoumon. Heparin was administered periprocedurally to achieve an activated clotting time of 280 to 300 seconds. No protamine was administered periprocedurally. The primary end point was a composite of bleeding, thromboembolic events, and death. The primary end point was met in 9 patients in the edoxaban group and in 22 patients in the phenprocoumon group (p = 0.69). No patient in either group died or had a thromboembolic complication. No major bleeding complication was observed in the edoxaban group, whereas one was found in 1 patient in the phenprocoumon group (p ≥0.99). Minor bleeding complications occurred in 9 patients (12%) in the edoxaban group and in 21 patients (14%) in the phenprocoumon group (p = 0.84). Uninterrupted OAC with edoxaban appeared to be as safe as uninterrupted OAC with phenprocoumon in patients who underwent LA RF ablation procedures.

Linear Ablation for AFBackground For persistent atrial fibrillation (AF) ablation, different strategies including complex fractionated atrial electrograms (CFAE) ablation and linear lesions (LL) have been used in addition to pulmonary vein isolation (PVI). However, it is still a matter of debate if extended substrate modification improves long-term outcome. The aim of this study was to determine the benefit of LL in addition to PVI and CFAE ablation regarding freedom from arrhythmia recurrence in patients with persistent AF. Methods The study was a prospective randomized trial including 90 patients with persistent and longstanding persistent AF. All patients underwent PVI and CFAE ablation. If AF did not terminate to atrial tachycardia (AT) or sinus rhythm, patients were randomized to direct current cardioversion (Group 1; n = 45) or LL (Group 2; n = 45). Primary endpoint was freedom from any atrial arrhythmia off antiarrhythmic drugs at 12 months. (NCT02059369) Results Baseline characteristics were similar between the two groups with more than half of the patients having structural heart disease. The primary endpoint was reached in 37% in Group 1 (G1) and 16% in Group 2 (G2; P = 0.03). After a total number of 1.4 ± 0.5 (G1) versus 1.7 ± 0.4 (G2; P = 0.01) procedures, freedom from any arrhythmia was reached in 54% in G1 and 65% in G2 (P = 0.35). Conclusion In persistent AF ablation, LL in addition to PVI and CFAE show a significantly lower success rate after a single procedure compared to PVI and CFAE. Following LL, significantly more patients needed a reablation to reach a similar success rate during a 12-month follow-up.

Purpose Electromagnetic interference (EMI) with implantable cardioverter defibrillators (ICDs) can cause oversensing and subsequently inappropriate ICD therapies. We retrospectively investigated the current incidence and clinical relevance of oversensing related EMI in a large cohort of ICD patients. Methods From January 2005 to April 2013, all ICD interrogations performed at our institution were analyzed for the occurrence of oversensing related EMI. EMI episodes were classified as clinically significant, potentially significant or of minor significance. To identify risk factors for EMI, we also analyzed different lead models in our cohort (integrated vs true bipolar leads). Results Data of 2940 ICD patients (mean age 63 ± 16 years, 2322 male patients, 7772 patient-years) were retrospectively analyzed for the occurrence of EMI. During the observation period, a total of 145 (hospital environment n = 97, non-hospital environment n = 48) episodes occurred and resulted in an overall EMI incidence, i.e. event rate, of 1.87 % per patient per year. Focusing on clinically significant or potentially significant episodes, the EMI incidence was 0.27 % per patient per year. Cox proportional hazards regression analysis did not reveal a statistically significant higher hazard of oversensing for patients with integrated bipolar leads compared to patients with true bipolar leads (HR = 2.21; 95 % CI 0.90-5.39; p = 0.083). Conclusions Our data demonstrate that EMI continues to occur in everyday life. Patients should be well informed about the potential sources and risks of EMI but they need not be overly concerned since the risk of EMI-especially in a non-hospital environment-is low.

Accuracy of Contact-Force SensingBackground Contact-force (CF) sensing catheters are increasingly used in clinical electrophysiological practice due to their efficacy and safety profile. As data about the accuracy of this technology are scarce, we sought to quantify accuracy based on in vitro experiments. Methods and Results A custom-made force sensor was constructed that allowed exact force reference measurements registered via a flexible membrane. A Smarttouch Surround Flow (ST SF) ablation catheter (Biosense Webster, Diamond Bar, CA, USA) was brought in contact with the membrane of the force sensor in order to compare the ST SF force measurements to force sensor reference measurements. ST SF force sensing technology is based on deflection registration between the distal and proximal catheter tip. The experiment was repeated for n = 10 ST SF catheters, which showed no significant difference in accuracy levels. A series of measurements (n = 1200) was carried out for different angles of force acting to the catheter tip (0°/perpendicular contact, 30°, 60°, 90°/parallel contact). The mean absolute differences between reference and ST SF measurements were 1.7 ± 1.8 g (0°), 1.6 ± 1.2 g (30°), 1.4 ± 1.3 g (60°), and 6.6 ± 5.9 g (90°). Measurement accuracy was significantly higher in non-parallel contact when compared with parallel contact (P < 0.01). Conclusions Catheter force measurements using the ST SF catheters show a high level of accuracy regarding differences to reference measurements and reproducibility. The reduced accuracy in measurements of 90° acting forces (parallel contact) might be clinically important when creating, for example, linear lesions.

Transseptal Puncture Guided by 3D-Fluoroscopy Background Transseptal puncture for left atrial (LA) access is still mainly performed using fluoroscopy and transesophageal or intracardiac echocardiography. We present an easily applicable approach for the guidance of transseptal puncture that uses the combination of a 3D-mapping system and CT-derived 3D-overlayed anatomy. Methods and Results A computer tomographic (CT) LA-angiography was performed in n = 65 patients prior to a scheduled atrial fibrillation ablation procedure. The CARTO3® (Biosense Webster, Diamond Bar, CA, USA) segmentation tool was used to create a 3D-reconstruction of cardiac anatomy and the spine. The CARTO UNIVU® module was then used to overlay and register the segmented 3D-anatomy onto fluoroscopy. The 3D-reconstructed spine and cardiac anatomy were congruently aligned to their fluoroscopic counterparts in fluoroscopic views. The feasibility of the technique, its safety, and accuracy (assessed as contour offsets between 3D-overlay and angiographic LA anatomy) were evaluated. Overlay registration accuracy was analyzed by CARTO3® registration matrices. Transseptal puncture was feasible without complications in all 65 patients using the new 3D-overlay technique. Three-dimensional-overlay contour offsets were 1.6 ± 1.2 mm in left PV, 1.7 ± 1.2 mm in right PV, and 1.3 ± 1.0 mm in the LA roof region. Overlay registration accuracy was 4.9 ± 2.7 mm. The average time needed for anatomy segmentation was 204 ± 61 seconds, time needed for overlay registration was 18 ± 8 seconds. Conclusions Three-dimensional-augmented fluoroscopy is feasible, safe, and easy to apply as guidance for transseptal puncture and demonstrates a high level of accuracy.

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Time has been postulated as an important factor for electrical remodeling of the left atrium (LA) in persistent atrial fibrillation (AF) ('AF begets AF'). However, it is still a matter of debate if structural changes are the cause or consequence of AF. We sought to determine the clinical and invasive parameters, which correlate with LA scar as determined by voltage mapping, in patients with persistent AF.Seventy consecutive patients undergoing ablation of persistent (49%) or long-standing persistent AF (51%), between January 2013 and February 2014, were enrolled in the study. Besides clinical parameters, 2D echocardiographic assessment of LA size and LA pressure (LAP) after transseptal puncture was also considered. Bipolar endocardial signals with a mean voltage amplitude 0.1 mV during AF were defined as LA scar.In the univariable analysis, LA scar was associated with age, gender, coronary artery disease (CAD), glomerular filtration rate (GFR), LA size and LAP. Arrhythmia duration, mild to moderate mitral regurgitation (MR), left ventricular dysfunction and left ventricular hypertrophy showed no significant correlation with atrial scar (all p 0.05). In a multivariable regression model, LA scar area was independently associated with age, female gender and LA area. AF duration was not associated with LA scar.In this study, older age, greater LA area and female gender predicted the degree of LA scar, while other variables tested did not. In particular, we found no significant association between AF duration and LA scar.

Introduction The aim of this study was to evaluate a spatial correlation between active atrial fibrillation (AF) drivers measured by electrocardiographic imaging and complex fractionated atrial electrograms (CFAEs) in patients with persistent AF. Methods Sixteen patients with persistent AF were included. A biatrial geometry relative to an array of 252-body-surface-electrodes was obtained from a noncontrast computed tomography scan. The reconstructed unipolar AF electrograms were signal-processed (ECVUE™, CardioInsight Technologies Inc., Cleveland, OH, USA) to identify AF drivers. Before driver ablation, a biatrial mapping using the NavX system (St. Jude Medical, St. Paul, MN, USA) was performed to identify CFAEs. CFAE and driver regions were then quantified and compared. Results AF was terminated by driver ablation in 11/16 (70%) patients. The mean number of ablated driver regions was 4 ± 1 per patient. The most frequent driver locations were the inferior left atrium and coronary sinus, the right pulmonary veins, and the right atrium. In 49/63 (78%) of the driver locations, more than 75% of the driver site showed CFAEs. The mean ablated driver area was 58 ± 24 cm2 (19 ± 11% of total surface area). The mean CFAE area was 178 ± 59 cm2 (49 ± 16%). The percentage of non-ablated CFAE area was 76 ± 13% of total CFAEs. In 9/11 patients with AF termination, the termination site showed CFAEs. Conclusions There is a significant overlap between AF driver regions identified by the ECVUE™ system and CFAE areas identified by the NavX system. AF driver regions are smaller and mostly embedded in larger CFAE areas. Selective ablation of drivers in CFAE areas seems sufficient to terminate persistent AF in the majority of patients.

Aims This study presents and evaluates the impact of a new lowest-dose fluoroscopy protocol (Siemens AG), especially designed for electrophysiology (EP) procedures, on X-ray dose levels. Methods and results From October 2014 to March 2015, 140 patients underwent an EP study on an Artis zee angiography system. The standard low-dose protocol was operated at 23 nGy (fluoroscopy) and at 120 nGy (cine-loop), the new lowest-dose protocol was operated at 8 nGy (fluoroscopy) and at 36 nGy (cine-loop). Procedural data, X-ray times, and doses were analysed in 100 complex left atrial and in 40 standard EP procedures. The resulting dose–area products were 877.9 ± 624.7 µGym² ( n = 50 complex procedures, standard low dose), 199 ± 159.6 µGym² ( n = 50 complex procedures, lowest dose), 387.7 ± 36.0 µGym² ( n = 20 standard procedures, standard low dose), and 90.7 ± 62.3 µGym² ( n = 20 standard procedures, lowest dose), P < 0.01. In the low-dose and lowest-dose groups, procedure times were 132.6 ± 35.7 vs. 126.7 ± 34.7 min ( P = 0.40, complex procedures) and 72.3 ± 20.9 vs. 85.2 ± 44.1 min ( P = 0.24, standard procedures), radiofrequency (RF) times were 53.8 ± 26.1 vs. 50.4 ± 29.4 min ( P = 0.54, complex procedures) and 10.1 ± 9.9 vs. 12.2 ± 14.7 min ( P = 0.60, standard procedures). One complication occurred in the standard low-dose and lowest-dose groups ( P = 1.0). Conclusion The new lowest-dose imaging protocol reduces X-ray dose levels by 77% compared with the currently available standard low-dose protocol. From an operator standpoint, lowest X-ray dose levels create a different, reduced image quality. The new image quality did not significantly affect procedure or RF times and did not result in higher complication rates. Regarding radiological protection, operating at lowest-dose settings should become standard in EP procedures.

Repeat procedures after persistent atrial fibrillation (AF) ablation are frequently performed for secondary atrial tachycardias (AT). Predictors of AT recurrence after the first repeat ablation have not yet been studied.We investigated predictors of AT recurrence in 117 patients who underwent ablation for secondary AT arising after a previous ablation for persistent AF using the Cox proportional hazards model.Acute ablation success rate was 94%. Over a follow-up period of 12 months, 61 patients (53%) were free from AT recurrence. Of the assessed predictors of AT recurrence, the number of ablated AT forms (>1 vs. 1) was significantly associated with AT recurrence (hazard ratio 2.01, 95% CI 1.18-3.43, P = 0.01). Other variables including left atrial diameter, AT mechanism, or the characteristics of previous AF ablation did not have significant influence on AT recurrence (P>0.05). Men had a tendency toward fewer AT recurrences than women (OR 0.60, 95% CI 0.34-1.05, P = 0.07). During a second AT ablation procedure, 19 (49%) patients were identified to have a recurrence of the previously ablated AT, whereas in 20 patients (51%) a new AT form was diagnosed.Ablation of atrial tachycardias following persistent AF ablation has a high acute success rate. However, a substantial number of patients develop new onset AT during follow-up. The occurrence of multiple AT forms during the repeat ablation procedure was the only predictive factor for AT recurrence.

Accuracy of MediGuide® Navigation Background Data about localization reproducibility as well as spatial and visual accuracy of the new MediGuide® sensor-based electroanatomic navigation technology are scarce. We therefore sought to quantify these parameters based on phantom experiments. Methods and Results A realistic heart phantom was generated in a 3D-Printer. A CT scan was performed on the phantom. The phantom itself served as ground-truth reference to ensure exact and reproducible catheter placement. A MediGuide® catheter was repeatedly tagged at selected positions to assess accuracy of point localization. The catheter was also used to acquire a MediGuide®-scaled geometry in the EnSite Velocity® electroanatomic mapping system. The acquired geometries (MediGuide®-scaled and EnSite Velocity®-scaled) were compared to a CT segmentation of the phantom to quantify concordance. Distances between landmarks were measured in the EnSite Velocity®- and MediGuide®-scaled geometry and the CT dataset for Bland–Altman comparison. The visualization of virtual MediGuide® catheter tips was compared to their corresponding representation on fluoroscopic cine-loops. Point localization accuracy was 0.5 ± 0.3 mm for MediGuide® and 1.4 ± 0.7 mm for EnSite Velocity®. The 3D accuracy of the geometries was 1.1 ± 1.4 mm (MediGuide®-scaled) and 3.2 ± 1.6 mm (not MediGuide®-scaled). The offset between virtual MediGuide® catheter visualization and catheter representation on corresponding fluoroscopic cine-loops was 0.4 ± 0.1 mm. Conclusions The MediGuide® system shows a very high level of accuracy regarding localization reproducibility as well as spatial and visual accuracy, which can be ascribed to the magnetic field localization technology. The observed offsets between the geometry visualization and the real phantom are below a clinically relevant threshold.

Background The impact of the CartoUnivu™ technology (Biosense Webster, Diamond Bar, CA, USA) on fluoroscopy exposure compared to a conventional approach using electroanatomical mapping (Carto 3™) was evaluated in patients undergoing radiofrequency ablation for ventricular tachyarrhythmias (VT). Methods and Results We prospectively evaluated 23 patients undergoing VT ablation using the CartoUnivu™ technology. The CartoUnivu™ Module integrates fluoroscopic images and cine loops into the electroanatomical mapping system. As a control group, 23 out of 88 VT patients (ablated using conventional fluoroscopy supplemented by electromagnetic mapping with the Carto 3™ System) were matched for age, gender, body surface area, operator, redo-procedure, presence of coronary artery disease, and left ventricular dysfunction using propensity score matching. A significant reduction in fluoroscopy exposure was observed in the CartoUnivu™ group when compared to the conventional group (10.57 ± 7.93 minutes vs 18.52 ± 11.24 minutes, P_= 0.008; 611 cGy/cm2 vs 1650 cGy/cm2, P = 0.001). In multivariate analysis, the CartoUnivu™ module was an independent predictor of reduced fluoroscopy use. Conclusion This is a report on the clinical application of the CartoUnivu system for VT ablation. CartoUnivu™ markedly reduced fluoroscopy time and dose compared to conventional fluoroscopy/electroanatomical mapping.

Aims In patients with paroxysmal atrial fibrillation (pAF), pulmonary vein isolation (PVI) has become an accepted treatment option with single procedure success rates of 60–80%. A repeat ablation is performed in ∼30% of patients because of arrhythmia recurrence. The strategy for this repeat procedure is not defined. Methods and results Patients with pAF recurrence after PVI were prospectively randomized and underwent a second ablation procedure with either PVI of all reconnected veins or PVI with an additional left atrial anterior line. Follow-up in our arrhythmia clinic was every 3 months up to 12 months including 7 day Holter monitoring. A total of 77 patients (mean age 63 ± 9 years, 69% males) were included in the analysis. A repeat PVI was performed in 41 patients, PVI + anterior line in 36 patients. After a follow-up of 12 months, 26 of 41 (63%) patients after repeat PVI and 18 of 36 (50%) patients with PVI + anterior line were in stable sinus rhythm off antiarrhythmic medication ( P = 0.26). In most patients (12 of 15 patients with PVI and 14 of 18 patients with PVI + anterior line) with an arrhythmia recurrence after the second procedure, the recurring arrhythmia was paroxysmal AF. In 2 of 15 patients of the PVI group and in 4 of 18 patients of the PVI + anterior line group atypical flutter was the reoccurring arrhythmia ( P = NS). Conclusion In this prospective randomized trial, patients with a recurrence of paroxysmal AF had no better outcome after repeat PVI + one left atrial line compared with patients with repeat PVI only.

Aims The modified anterior line (MAL) is an alternative to the mitral isthmus (MI) line for the treatment of perimitral atrial flutter (PMFL). We sought to investigate acute and long-term efficacy of this line if routinely used for PMFL. Methods and results The cohort included 77 consecutive patients who underwent catheter ablation of PMFL. The anterior line was deployed between the anterolateral mitral annulus and the ostium of the left superior pulmonary vein. Perimitral atrial flutter was either the presenting arrhythmia after persistent atrial fibrillation (AF) ablation (Group 1, n = 42, 54.5%), occurring during AF ablation (Group 2, n = 25, 35%) or presenting as primary arrhythmia (Group 3, n = 8, 10%). Acute success was defined as PMFL termination during MAL deployment with demonstration of bidirectional line block. Acute success was achieved in 68 of 77 patients (88%) without difference between the three groups. In five patients an additional MI line was necessary to terminate PMFL and in four patients both lines failed to achieve termination. During follow-up (16 ± 7 months), 38 of 77 (49%) patients underwent a repeat procedure for a recurrent arrhythmia. During reablation, 13 of 38 (34%) patients were identified to have a PMFL recurrence. Persistent MAL block was demonstrated in 22 of 38 (58%) patients during the repeat ablation. Conclusion The MAL is effective for acute and long-term treatment of PMFL. Maintenance of bidirectional MAL block was shown in 58% of patients during a repeat ablation.

In some patients, both an electrophysiological examination (EPS) and a coronary angiography (CA) are necessary. It might be preferable to choose a combined approach of EPS and CA versus performing them consecutively. The purpose of this study is to evaluate the type and rate of adverse events between both approaches. Patients were eligible if they underwent a CA and an EPS in a combined approach or in a time interval of at most 2 months. In all patients, clinical adverse events were recorded. A total of 1184 patients were included. CA and EPS were performed in a combined procedure (comb) in 492 patients, whereas they were performed consecutively in 692 patients (cons). The acute major complication rate was 0.67%, showing no differences between both groups. In the comb 6.9% and in the cons 6.6% of vascular complications were observed (p = 0.20). The rates of AV fistula and hematoma needing transfusion showed a significantly higher rate in the cons group (p = 0.018 and p = 0.045, respectively). In a multivariate logistic regression analysis, age was a significant predictor for groin complications. After propensity matching, AV fistula occurred significantly more often in the cons group (p = 0.002). Overall, serious adverse events were rare and there were no differences between the combined approach of EPS and CA and the consecutive approach; however, the occurrence of AV fistula and groin hematoma needing transfusion occurred significantly less in the combined procedure group. Therefore, a combined approach is preferable to a consecutive one.

Remote magnetic navigation (RMN) is attributed to diminish radiation exposure for both patient and operator performing catheter ablation for different arrhythmia substrates. The purpose of this prospective, randomized study was to compare RMN with manually guided catheter ablation for AV nodal reentrant tachycardia (AVNRT) regarding fluoroscopy time/dosage, acute and long-term efficacy as well as safety. A total of 218 patients with AVNRT undergoing catheter ablation at three centers (male 34%, mean age 50 ± 17 years) were randomized to a manual approach (n = 113) or RMN (n = 105) using the Niobe® magnetic navigation system. The primary study endpoint was total fluoroscopy time/dosage for patient and operator at the end of the procedure. Secondary endpoints included acute success, procedure duration, complications and success rate after 6 months. Fluoroscopy time and dosage for the patient were significantly reduced in the RMN group compared to the manual group (6 ± 6 vs. 11 ± 10 min; p

The role of dissociated pulmonary vein (DPV) activity after pulmonary vein isolation (PVI) is still poorly defined. We evaluated electrophysiological features and clinical impact on long-term outcome of DPV activity.A total of 243 patients (mean age 63 ± 11 years; 63% males) undergoing PVI for paroxysmal atrial fibrillation (AF) were included. DPV activity was defined as a residual low frequency irregular PV rhythm. Patients were divided into Group 1 (presence of DPV activity; n = 65) or Group 2 (absence of DPV activity; n = 178).Of 936 isolated PVs, 112 PVs (12%) showed DPV activity. DPV activity was observed more frequently in PVs identified as AF triggers (P = 0.026). During follow-up (mean 12 ± 7 months), 15 of 65 patients of Group 1 (23%) and 57 of 178 patients of Group 2 (32%) had an arrhythmia recurrence (P = 0.23). At linear regression analysis, no independent predictor for clinical recurrence was identified. During the repeat ablation, 62 of 72 patients (86%) showed a recovered PV conduction without difference between the 2 groups. Clinically, all patients of Group 1 with PV reconnection (n = 13/15) had a recurrence of paroxysmal AF. In Group 2, 5 of 52 patients with reconnected PV developed non-PV related arrhythmias.DPV activity occurred in 12% of PVs after PVI and was observed more frequently in PVs identified as AF triggers. DPV activity was not predictive for AF recurrence during follow-up. PV-left atrium reconnection involving PVs with DPV activity leads to AF.

Background— This study aimed to evaluate the safety of continuous periprocedural rivaroxaban administration during left atrial radiofrequency ablation (RFA) in comparison with uninterrupted oral vitamin K antagonist administration. Data about the use of rivaroxaban in the setting of left atrial RFA procedures are lacking. Methods and Results— The study cohort included 544 patients (mean age, 63±10 years) who underwent left atrial RFA procedures between February 2012 and May 2013. All patients (n=272) receiving uninterrupted periprocedural rivaroxaban 15 or 20 mg/d before the procedure (rivaroxaban) were matched by age, sex, and type of rhythm disorder with an equal number of patients managed with uninterrupted vitamin K antagonist phenprocoumon (international normalized ratio, 2–3). During RFA, heparin was given intravenously to maintain an activated clotting time at 270 to 300 s. The safety end point was a composite of bleeding, thromboembolic events, and death. There were no thromboembolic complications and no deaths in either group. The prevalence of major bleeding complications was similar in both groups (1 tamponade in RivG and 1 groin hematoma requiring transfusion in phenprocoumon). Minor bleeding complications occurred equally in both groups (20 of 272; 7% in the rivaroxaban versus 33 of 272, 12% in the phenprocoumon; P =0.08). In multivariable analyses, female sex was associated with a greater risk of complications (odds ratio, 1.96; 95% confidence interval, 1.10–3.49). Conclusions— In patients undergoing left atrial RFA, continuous periprocedural rivaroxaban use seems to be as safe as uninterrupted periprocedural phenprocoumon administration.

A short baseline atrial fibrillation (AF) cycle length (CL) has been associated with a worse outcome after catheter ablation for AF, whereas the impact of a long baseline AFCL is unknown. We investigated the influence of AFCL on acute and long-term success in a large series of patients undergoing catheter ablation for persistent AF. Overall, 177 consecutive patients undergoing catheter ablation of persistent AF using a sequential ablation approach were included in the analysis. AFCL was measured in the left atrial appendage (LAA) at baseline and following each ablation step. The primary endpoint was freedom from any atrial arrhythmia off antiarrhythmic drugs (AAD) with a single ablation procedure after 12 months. Mean AFCL was 164 ± 24 ms. A shorter AFCL was associated with longer AF duration, larger LA diameter, and longer procedure duration. Termination to sinus rhythm (SR) was achieved in 57 (32 %) patients. Baseline AFCL was shorter (161 ± 24 ms) in patients without AF termination compared to patients with AF termination (169 ± 23 m, p = 0.03). The primary endpoint was reached less frequently in patients with a short (

Background Ablation procedures in patients with paroxysmal atrial fibrillation (PAF) includes isolation of all pulmonary veins (PVs). We hypothesized that an approach using an algorithm to detect arrhythmogenic PVs (aPVs) might lead to shorter procedure duration (PD) and fewer proarrhythmic effects (PE). Hypothesis Isolation of the aPVs only leads to a reduced PD, reduced PEs, and fewer adverse events, with a success rate comparable to the standard all-PV approach. Methods In this prospective trial, 207 patients with PAF were randomized to undergo isolation of the aPV (AG group, n = 105) or isolation of all PVs (VG group, n = 102). The aPV was identified by atrial fibrillation (AF) induction, focal discharge, or short local PV decremental conduction during PV pacing. Patients were followed with repetitive 7-day Holter electrocardiograms (ECGs) after 3, 6, and 12 months in our arrhythmia clinic. Results In 97% of patients, at least 1 aPV was identified (mean, 2.1). PD did not differ significantly (152.3 ± 57.1 minutes vs 162 ± 68 minutes, P = 0.27) between the groups, but the number of radiofrequency (RF) applications and fluoroscopy time (FT) and dose were significantly lower in the AG group than in the VG group. The occurrence of PE (new-onset atrial tachycardia) and adverse events (AE) did not differ between the 2 groups (P = 0.1). Sinus rhythm off antiarrhythmic medication (documented on 7-day Holter ECGs) 12 months after a single procedure was achieved in 53% in the AG group and 59% in the VG group (P = 0.51). Conclusions Isolation of the aPVs detected by a straightforward algorithm leads to similar success rates compared to a standard all-PV approach with regard to PD, AE, or PE and is associated with less RF and a shorter FT.

Endovascular renal denervation techniques have been clinically adopted for the treatment of resistant arterial hypertension with great success. Despite the favourable early results achieved with this technology, a clear understanding of the pathophysiology underlying this novel treatment is lacking. In addition, non-responsiveness to renal denervation remains a nidus for treatment failure in distinct patients. In search of meaningful surrogate parameters relating to treatment responsiveness, the current article reviews the existing knowledge on renal nerve anatomy, changes occurring after denervation and procedural parameters collected during denervation. From preclinical experience, the most reliable morphological parameter reflecting successful renal denervation is the presence of axonal degeneration. Most procedural and clinical parameters need extended investigation before adopting them as potential surrogate parameters for successful renal denervation. As a consequence, there is an imperative need for dedicated research revealing the pathophysiology of renal denervation procedures. In this regard, close co-operation of engineers, researchers and clinicians is warranted to turn renal denervation into a milestone treatment of arterial hypertension.

Endpoint of Persistent AF Ablation. Background: The endpoint of persistent atrial fibrillation (AF) ablation is still a matter of debate. The purpose of this study was to evaluate if sinus rhythm (SR) as endpoint of persistent AF ablation has a better long-term outcome compared to atrial tachycardia (AT) or AF at the end of the procedure. Methods and Results: Between 2008 and 2011, 191 consecutive patients undergoing de novo catheter ablation for symptomatic persistent and long-standing persistent AF using a sequential ablation approach (including pulmonary vein isolation, ablation of complex fractionated electrograms and linear lesions) were included in the study. According to the result at the end of ablation procedure, patients were classified into 3 groups: patients with termination of AF into SR (Group 1, n = 62), patients with AT undergoing cardioversion (CV) (Group 2, n = 47), or patients with AF undergoing CV (Group 3, n = 82). The primary endpoint was freedom from any atrial tachyarrhythmia off antiarrhythmic drugs at 12 months. At 12 months, estimated proportions of patients free from any arrhythmia recurrence were 42% for Group 1, 13% for Group 2, and 25% for Group 3 (P = 0.002). In a Cox regression analysis only termination into SR was associated with a lower risk of arrhythmia recurrence (HR: 0.62; P = 0.04). Conclusion: If SR is achieved as endpoint of persistent and long-standing persistent AF ablation using a sequential ablation approach it is associated with the highest long-term single procedure success rate compared to AT or AF at the end of the procedure. (J Cardiovasc Electrophysiol, Vol. 24, pp. 388-395, April 2013)

For persistent atrial fibrillation (AF) ablation, different strategies including complex fractionated atrial electrograms (CFAE) ablation and linear lesions (LL) have been used in addition to pulmonary vein isolation (PVI). However, it is still a matter of debate if extended substrate modification improves long-term outcome. The aim of this study was to determine the benefit of LL in addition to PVI and CFAE ablation regarding freedom from arrhythmia recurrence in patients with persistent AF.The study was a prospective randomized trial including 90 patients with persistent and longstanding persistent AF. All patients underwent PVI and CFAE ablation. If AF did not terminate to atrial tachycardia (AT) or sinus rhythm, patients were randomized to direct current cardioversion (Group 1; n = 45) or LL (Group 2; n = 45). Primary endpoint was freedom from any atrial arrhythmia off antiarrhythmic drugs at 12 months. (NCT02059369) RESULTS: Baseline characteristics were similar between the two groups with more than half of the patients having structural heart disease. The primary endpoint was reached in 37% in Group 1 (G1) and 16% in Group 2 (G2; P = 0.03). After a total number of 1.4 ± 0.5 (G1) versus 1.7 ± 0.4 (G2; P = 0.01) procedures, freedom from any arrhythmia was reached in 54% in G1 and 65% in G2 (P = 0.35).In persistent AF ablation, LL in addition to PVI and CFAE show a significantly lower success rate after a single procedure compared to PVI and CFAE. Following LL, significantly more patients needed a reablation to reach a similar success rate during a 12-month follow-up.

Remote magnetic navigation systems are used for catheter navigation in cardiac electrophysiological ablation procedures. In this setting, ferromagnetic particles will be moved by changes in the magnetic field. It is unknown to what extent cardiac implantable electronic devices (CIED) are affected by the magnetic field when using magnetic navigation, and whether these forces may exceed the limit of 5 N that is set forth by German and European norms for implanted electrodes. A total of 121 rhythm devices were examined in a magnetic field of 0.1 T using the NIOBE II® Magnetic Navigation System (Stereotaxis, St. Louis, USA). Forces acting on the devices were measured with the force measurement tool Futek LRF 400 (Futek Advanced Sensor Technology Inc., Irvine, CA, USA). A standardized protocol of different movements of the magnetic field including all three dimensions was performed and maximal forces on the CIED were assessed. Out of 121 devices, 78 different pacemakers (54 different model families from 11 manufacturers) and 43 different cardioverter-defibrillators (26 different model families from 6) were examined. The mean force that could be observed was 0.33 ± 0.13 N for pacemakers (range 0.16–1.12 N) and 1.05 ± 0.11 N for cardioverter-defibrillators (range 0.86–1.38 N) when exposed to the magnetic field. Exposure of pacemakers or implantable cardioverter-defibrillators to a magnetic field of 0.1 T does not result in a force exceeding the regulatory demanded 5 N that could damage the connected leads.

Aims Data about the long-term outcome after cryoablation for atrioventricular nodal reentrant tachycardia (AVNRT) in the paediatric population indicate that recurrence rates are higher with cryo than with radiofrequency energy (RF). The purpose of this study was to review our institutional long-term outcome after cryoablation for AVNRT and to seek for predictors of recurrence. Methods and results Forty-nine patients (28 female, age 14 ± 2.7 years) undergoing slow-pathway modulation or ablation for AVNRT at our institution from 2004 to 2008 were included in the study. Acute success was obtained in all patients (100%) with a mean procedure time of 164 ± 50 min and a mean fluoroscopy time of 13 ± 8 min. During a follow-up time of 30 ± 1.9 months, AVNRT recurrence occurred in 11/49 patients (22.4%). Age, sex, number of cryomappings or ablations, catheter tip (4 mm vs. 6 mm), or ablation endpoint (slow-pathway ablation vs. modulation) were not predictive for recurrence. In eight patients, reablation using cryo was performed. All these patients remained free of arrhythmia symptoms during a follow-up of 30 ± 8 months following the second procedure. Conclusion Although cryoablation for the treatment for AVNRT in paediatric and adolescent patients is safe and associated with a high acute success rate, AVNRT recurrence occurs in 22% of patients during long-term follow-up without identifiable predictors for recurrence. A second cryoablation procedure leads to a success rate of 100% during long-term follow-up.

Quality of Life After Ablation for Atrial Fibrillation. Background: This study prospectively assesses different aspects of short- and long-term quality of life (QoL) after catheter ablation for atrial fibrillation (AF). An analysis of 7 validated generic and tailored questionnaires was performed with regard to the relation of QoL to ablation success. Methods: The study included 133 patients (74% men, age 57±10) who underwent pulmonary vein isolation ± linear or electrogram-guided substrate modification for AF. QoL was quantitatively assessed at baseline, 3 months after ablation and at a median of 4.3 ± 0.5 years after ablation by the AF severity scale (AFSS), AF symptom checklist (AFSC), WHO-5-Well-Being-Index (WHO), Major Depression Inventory (MDI), Sleep and Vegetative disorder (SV), Vital Exhaustion (VE), and Illness intrusiveness (Ii). Results: QoL was improved significantly 3 months after ablation in all patients (regardless of ablation success or AF type) and stayed significantly improved after a median of 4.3±0.5 years (AFSS, AFSC, WHO, MDI, VE, PE (all P < 0.001), and SV (P = 0.007)). Patients who had a successful ablation improved significantly more than patients with an unsuccessful ablation in the AFSS, AFSC, and MDI questionnaire (delta change from baseline to long-term follow-up P =

Sirs: Patients after device closure of an atrial septal defect (ASD) presenting with left atrial (LA) arrhythmias are a challenge for the electrophysiologist as conventional transseptal puncture might be demanding. In patients with complex congenital heart disease, remote magnetic navigation (RMN) has been used to access anatomical structures that are difficult to reach [1–3]. The present case demonstrates the feasibility and efficacy of a complex LA ablation procedure for persistent atrial fibrillation (AF) via a retrograde aortic approach using RMN [4]. A 46-year-old woman with a history of a large secundum ASD had undergone successful transcatheter ASD occlusion with a 30-mm Amplatzer Occluder (AGA Medical Corp., Plymouth, MN, USA) 5 years ago. In 2012, successful ablation of typical atrial flutter had been performed. Subsequently, the patient developed persistent AF and complained of palpitations and shortness of breath. After electrical cardioversion, AF recurred and neither flecainide nor amiodarone was efficient. The patient was referred to our center for a second opinion. The echocardiogram showed no residual interatrial shunt, a normal ventricular ejection fraction and moderate dilation of both atria (LA anteroposterior diameter of 46 mm) (Fig. 1a). We decided to offer the patient an AF ablation via a retrograde approach using the Niobe II magnetic navigation system (Stereotaxis, St. Louis, MO, USA). The procedure was performed under conscious sedation. A 6F octapolar Bard EP-XT Steerable Catheter was advanced into the coronary sinus (CS). A 3.5-mm-tip irrigated magnetic catheter (Thermocool RMT, Biosense Webster, Diamond Bar, CA, USA) was inserted through a short 8F sheath in the femoral artery and manually advanced just below the subclavian artery. The ablation catheter was maneuvered across the aortic and mitral valve to the LA (Fig. 1b). Heparin was used to maintain the activated clotting time at the level of 300 s. An electroanatomic map of the LA using a three-dimensional (3D) mapping system (Carto3 RMT; Biosense Webster, Diamond Bar, CA, USA) was performed integrating a complex fractionated atrial electrogram (CFAE) software allowing automatical detection of CFAE sites (Fig. 2). After mapping, circumferential pulmonary vein isolation (PVI) was performed. CFAE ablation guided by the CFAE map and the operators’ judgment of local electrograms followed. Details of the CFAE ablation have been described previously [5, 6]. The endpoint of electrogram-guided ablation was elimination of all CFAE areas or AF conversion to atrial tachycardia or sinus rhythm. The effect of ablation was assessed by AF cycle length (AFCL). CFAE ablation was mainly performed at the anterior wall [including left atrial appendage (LAA)], inferior LA and LA roof with 30–35 W and a maximal temperature of 43 with an irrigation rate of 30 mL/min. After CFAE ablation, the AFCL measured in the LAA had prolonged significantly from 140 ms at baseline to 170 ms. Sinus rhythm was restored with direct current cardioversion. PV isolation was confirmed by mapping the ablation line around the PV and assessing the absence of PV potentials with the map catheter. The total procedure duration was 396 min. The total radiofrequency (RF) delivery time was 131 min (min) and the total fluoroscopy time was 6 min. No adverse events were observed. The patient was followed every 3 months in outpatient clinic with repeated 7-day holter ECGs. The endpoint was A. Buiatti (&) G. Hessling V. Semmler S. Ammar Department of Electrophysiology, German Heart Center Munich, Munich, Germany e-mail: elam4@libero.it

Background— Cryoablation has emerged as an alternative to radiofrequency catheter ablation (RFCA) for the treatment of atrioventricular (AV) nodal reentrant tachycardia (AVNRT). The purpose of this prospective randomized study was to test whether cryoablation is as effective as RFCA during both short-term and long-term follow-up with a lower risk of permanent AV block. Methods and Results— A total of 509 patients underwent slow pathway cryoablation (n=251) or RFCA (n=258). The primary end point was immediate ablation failure, permanent AV block, and AVNRT recurrence during a 6-month follow-up. Secondary end points included procedural parameters, device functionality, and pain perception. Significantly more patients in the cryoablation group than the RFCA group reached the primary end point (12.6% versus 6.3%; P =0.018). Whereas immediate ablation success (96.8% versus 98.4%) and occurrence of permanent AV block (0% versus 0.4%) did not differ, AVNRT recurrence was significantly more frequent in the cryoablation group (9.4% versus 4.4%; P =0.029). In the cryoablation group, procedure duration was longer (138±54 versus 123±48 minutes; P =0.0012) and more device problems occurred (13 versus 2 patients; P =0.033). Pain perception was lower in the cryoablation group ( P Conclusions— Cryoablation for AVNRT is as effective as RFCA over the short term but is associated with a higher recurrence rate at the 6-month follow-up. The risk of permanent AV block does not differ significantly between cryoablation and RFCA. The potential benefits of cryoenergy relative to ablation safety and pain perception are counterbalanced by longer procedure times, more device problems, and a high recurrence rate. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00196222.

Background: There are few data about the incidence of very late (>12 months) arrhythmia relapse after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) and about the success rate of repeat ablation procedures in this population. Methods: All patients treated with PVI for paroxysmal AF were screened in the institution's electrophysiology database. Follow-up data at 1, 3, 6, and 12 months and yearly thereafter including repetitive (7 days or 1 day) Holter electrocardiograms were assessed as well as the technique and success rate of repeat ablations. Results: Overall, 24 of 356 (6.7%) patients experienced their first AF recurrence more than 12 months after PVI. Of these 24 patients, 14 underwent reablation for paroxysmal (11 patients) or persistent AF (three patients). Repeat ablation included re-PVI in all 14 patients (43 of 48 initially isolated PVs with recovered left atrial–PV conduction). Ablation of complex fractionated atrial electrograms or left/right atrial lines was performed in eight patients, including the three patients with persistent AF. During follow-up of 15.1 ± 9 months after the second ablation, 10 of 14 (71%) reablated patients remained in sinus rhythm. Conclusions: After PVI for paroxysmal AF, very late arrhythmia recurrence occurs in less than 10% of patients. The success rate of the repeat procedure is high. (PACE 2010; 33:1258–1263)

The survival of patients with idiopathic dilated cardiomyopathy (IDCM) at III and IV stages of New York Heart Association (NYHA) is decreased in those with a bundle branch block (BBB) compared to those without BBB. Less is known on the prognosis of patients at earlier stages of NYHA and who had a left BBB (LBBB) or right BBB (RBBB). We sought to evaluate the prevalence and the clinical significance of LBBB or RBBB in patients with IDCM and classes I and II of NYHA.Clinical data, noninvasive, and invasive studies were consecutively collected in 310 patients, with IDCM, followed up to 4.8+/-3.7 years.Seventy-six patients (25%) had LBBB, 21 (7%) had RBBB, and 212 had no BBB. Patients with BBB were older than other patients (P0.009). Left ventricular ejection fraction (LVEF) was lower in LBBB than in RBBB and other patients (P0.05). Syncope was more frequent in BBB than in absence (P0.05). Incidence of spontaneous ventricular tachycardia (VT) and atrial fibrillation, VT induction, total cardiac events, and sudden death were similar in the presence or absence of BBB. Deaths by heart failure and heart transplantations tended to be more frequent in BBB than in absence.LBBB was present in 25% of patients with IDCM; RBBB was rare. Patients with BBB were older and had more frequent syncope than patients without BBB; LVEF was lower in LBBB than in RBBB or in absence of BBB. BBB did not increase the risk of spontaneous VT, VT induction, or sudden death, and tended to increase deaths by heart failure and the indications of heart transplantation.

Aims Syncope in Wolff–Parkinson–White (WPW) syndrome may reveal an arrhythmic event or is not WPW syndrome related. The aim of the study is to evaluate the results of electrophysiological study in WPW syndrome according to the presence or not of syncope and the possible causes of syncope. Methods and results Among 518 consecutive patients with diagnosis of WPW syndrome, 71 patients, mean age 34.5+ 17, presented syncope. Transoesophageal electrophysiological study in control state and after isoproterenol infusion was performed in the out-patient clinic. Atrioventricular re-entrant tachycardia (AVRT) was more frequently induced than in asymptomatic patients (n ¼ 38, 53.5%, P , 0.01), less frequently than in those with tachycardia; atrial fibrillation (AF) and/or antidromic tachycardia (ATD) was induced in 28 patients (39%) more frequently (P , 0.05) than in asymptomatic patients or those with tachycardia. The incidence of high-risk form [rapid conduction over accessory pathway (AP) and AF or ATD induction] was higher in syncope group (n ¼ 18, 25%, P , 0.001) than in asymptomatic subjects (8%) or those with tachycardias (7.5%). Maximal rate conducted over AP was similar in patients with and without syncope, and higher in patients with spontaneous AF, but without syncope. Results were not age-related. Conclusion Tachycardia inducibility was higher in patients with syncope than in the asymptomatic group. The incidence of malignant WPW syndrome was higher in patients with syncope than in asymptomatic or symptomatic population, but the maximal rate conducted over AP was not higher and another mechanism could be also implicated in the mechanism of syncope.

SummaryBackgroundScreening for Wolff-Parkinson-White (WPW) syndrome is recommended in children and young adults. The aim of this study was to evaluate the clinical and electrophysiological characteristics of patent WPW syndrome in subjects ≥60 years of age.MethodsFour-hundred and fifty-nine consecutive patients with WPW syndrome, aged 8–80 years, were recruited; 32 (7%) of these patients were ≥60 years of age. The clinical, electrophysiological and therapeutic data for these patients were evaluated.ResultsSixteen men and 16 women, aged 60–81 years (67±4.5), were admitted for resuscitated sudden death (1), rapid atrial fibrillation (4), syncope (4), or junctional tachycardia (13); 10 patients were asymptomatic (10). Left lateral bundles of Kent were detected more frequently in patients over 60 years (56%) than in those < 60 years of age (40.5%). Reciprocal tachycardia was induced in 58% of subjects

Aims To determine the feasibility and the results of exercise testing (ET) and electrophysiological study (EPS) in outpatient asymptomatic children with a Wolff-Parkinson-White (WPW) syndrome. Methods and results Exercise testing and transesophageal EPS were performed in 55 outpatient asymptomatic children aged 6 to 19 years old (14 ± 3) with WPW. Wolff-Parkinson-White persisted during maximal exercise. Isoproterenol was not required in five children younger than 10 years old, because they developed a catecholaminergic sinus tachycardia. Maximal rate conducted through accessory pathway (AP) was higher in children younger than 16 years old than in teenagers ( P < 0.05). Atrioventricular re-entrant tachycardia (AVRT) was induced in six children; atrial fibrillation (AF) in 12 children. The induction of tachycardias and the dangerous forms (18%) were not influenced by age. After 5 ± 1 years, one child, 12 year old with inducible rapid AF, had a sudden cardiac arrest; two children became symptomatic after ablation. Conclusions Transesophageal EPS was required to determine the prognosis of asymptomatic WPW in children. The maximal rate conducted in AP was higher in children younger than 16 years old than in teenagers; other data did not differ. AVRT was rare; 71% of children had no inducible arrhythmia and were authorized to resume physical activities.

Resume La signification de la fibrillation auriculaire (FA) dans la cardiomyopathie dilatee primitive (CMD) reste discutee. Le but de l'etude a ete d'evaluer les donnees cliniques, electrophysiologiques et pronostiques de patients ayant une CMD et une FA permanente en comparaison avec des sujets en rythme sinusal. Methodes Trois cent vingt-trois patients ayant une CMD primitive et une fraction d'ejection du ventricule gauche (FEVG) inferieure a 40 % ont ete hospitalises pour des tachycardies ventriculaires (TV) ( n = 69), des syncopes ( n = 103) ou des TV non soutenues sur l'enregistrement Holter ( n = 151). 65 etaient en FA permanente (groupe I), les autres en rythme sinusal (groupe II). Un enregistrement Holter, une mesure de la FEVG et une etude electrophysiologique ont ete realises. Les patients ont ete suivis pendant 3 ± 2 ans. Resultats Les patients du groupe I sont plus souvent des hommes et sont plus vieux que ceux du groupe II (61 ± 8 vs 52 ± 12 ans). Les syncopes (31 vs 36 %), les TV soutenues spontanees (18 vs 23 %), la FEVG (28 ± 9 vs 29 ± 9 %) et l'induction d'une TV (25 vs 35 %) sont similaires dans les deux groupes. Il n'y a pas de difference significative quant aux risques de mort subite (1,5 vs 5 %), de deces lies a une insuffisance cardiaque (5 vs 7 %) ou de transplantation cardiaque (8 vs 3 %). Conclusion Les patients avec CMD primitive et FA permanente sont plus âges que ceux en rythme sinusal. Les autres donnees cliniques, electrophysiologiques et pronostiques ne sont pas affectees par la FA.

Transseptal puncture for left atrial (LA) access is still mainly performed using fluoroscopy and transesophageal or intracardiac echocardiography. We present an easily applicable approach for the guidance of transseptal puncture that uses the combination of a 3D-mapping system and CT-derived 3D-overlayed anatomy.A computer tomographic (CT) LA-angiography was performed in n = 65 patients prior to a scheduled atrial fibrillation ablation procedure. The CARTO3 (Biosense Webster, Diamond Bar, CA, USA) segmentation tool was used to create a 3D-reconstruction of cardiac anatomy and the spine. The CARTO UNIVU module was then used to overlay and register the segmented 3D-anatomy onto fluoroscopy. The 3D-reconstructed spine and cardiac anatomy were congruently aligned to their fluoroscopic counterparts in fluoroscopic views. The feasibility of the technique, its safety, and accuracy (assessed as contour offsets between 3D-overlay and angiographic LA anatomy) were evaluated. Overlay registration accuracy was analyzed by CARTO3 registration matrices. Transseptal puncture was feasible without complications in all 65 patients using the new 3D-overlay technique. Three-dimensional-overlay contour offsets were 1.6 ± 1.2 mm in left PV, 1.7 ± 1.2 mm in right PV, and 1.3 ± 1.0 mm in the LA roof region. Overlay registration accuracy was 4.9 ± 2.7 mm. The average time needed for anatomy segmentation was 204 ± 61 seconds, time needed for overlay registration was 18 ± 8 seconds.Three-dimensional-augmented fluoroscopy is feasible, safe, and easy to apply as guidance for transseptal puncture and demonstrates a high level of accuracy.

Contact-force (CF) sensing catheters are increasingly used in clinical electrophysiological practice due to their efficacy and safety profile. As data about the accuracy of this technology are scarce, we sought to quantify accuracy based on in vitro experiments.A custom-made force sensor was constructed that allowed exact force reference measurements registered via a flexible membrane. A Smarttouch Surround Flow (ST SF) ablation catheter (Biosense Webster, Diamond Bar, CA, USA) was brought in contact with the membrane of the force sensor in order to compare the ST SF force measurements to force sensor reference measurements. ST SF force sensing technology is based on deflection registration between the distal and proximal catheter tip. The experiment was repeated for n = 10 ST SF catheters, which showed no significant difference in accuracy levels. A series of measurements (n = 1200) was carried out for different angles of force acting to the catheter tip (0°/perpendicular contact, 30°, 60°, 90°/parallel contact). The mean absolute differences between reference and ST SF measurements were 1.7 ± 1.8 g (0°), 1.6 ± 1.2 g (30°), 1.4 ± 1.3 g (60°), and 6.6 ± 5.9 g (90°). Measurement accuracy was significantly higher in non-parallel contact when compared with parallel contact (P0.01).Catheter force measurements using the ST SF catheters show a high level of accuracy regarding differences to reference measurements and reproducibility. The reduced accuracy in measurements of 90° acting forces (parallel contact) might be clinically important when creating, for example, linear lesions.

Repeat procedures after persistent atrial fibrillation (AF) ablation are frequently performed for secondary atrial tachycardias (AT). Predictors of AT recurrence after the first repeat ablation have not yet been studied.We investigated predictors of AT recurrence in 117 patients who underwent ablation for secondary AT arising after a previous ablation for persistent AF using the Cox proportional hazards model.Acute ablation success rate was 94%. Over a follow-up period of 12 months, 61 patients (53%) were free from AT recurrence. Of the assessed predictors of AT recurrence, the number of ablated AT forms (1 vs. 1) was significantly associated with AT recurrence (hazard ratio 2.01, 95% CI 1.18-3.43, P = 0.01). Other variables including left atrial diameter, AT mechanism, or the characteristics of previous AF ablation did not have significant influence on AT recurrence (P0.05). Men had a tendency toward fewer AT recurrences than women (OR 0.60, 95% CI 0.34-1.05, P = 0.07). During a second AT ablation procedure, 19 (49%) patients were identified to have a recurrence of the previously ablated AT, whereas in 20 patients (51%) a new AT form was diagnosed.Ablation of atrial tachycardias following persistent AF ablation has a high acute success rate. However, a substantial number of patients develop new onset AT during follow-up. The occurrence of multiple AT forms during the repeat ablation procedure was the only predictive factor for AT recurrence.

Aims First-line ablation prior to antiarrhythmic drug (AAD) therapy is an option for symptomatic paroxysmal atrial fibrillation (PAF); however, the optimal ablation technique, radiofrequency (RF), or cryoballoon (CB) has to be determined. Methods and results The FREEZE Cohort Study compares RF and CB ablation. Treatment-naive patients were documented in the FREEZEplus Registry. Periprocedural data and outcome were analysed. From 2011 to 2014, a total of 373/4184 (8.9%) patients with PAF naive to AAD were identified. Pulmonary vein isolation (PVI) was performed with RF ( n = 180) or CB ( n = 193). In the RF group, patients were older (65 vs. 61 years, P < 0.01) compared with the CB group. The procedure time was significantly shorter and radiation exposure higher in the CB group. Major adverse events occurred in 1.6% (CB) and 3.7% (RF) of patients ( P = 0.22). AF/atrial tachycardia (AT) recurrence until discharge was 4.5% (RF) and 8.5% (CB, P = 0.2). Follow-up (FU) ≥12 months was available in 99 (RF) and 107 (CB) patients. After 1.4 years of FU, freedom from AF/atrial tachycardia (AT) was 61% (RF) and 71% (CB, P = 0.11). In the RF group, more patients underwent cardioversion, and a trend for more repeat ablations was observed. Persistent phrenic nerve palsy was observed in one patient treated by CB. Conclusion First-line ablation for PAF is safe and effective with either RF or CB. The procedure was faster with the CB, but the radiation exposure was higher. Although there was a trend for more recurrences and complications in the RF group, a more favourable risk profile in patients undergoing CB ablation might have biased the results. ClinicalTrials.gov identifier NCT01360008.

Data about localization reproducibility as well as spatial and visual accuracy of the new MediGuide® sensor-based electroanatomic navigation technology are scarce. We therefore sought to quantify these parameters based on phantom experiments.A realistic heart phantom was generated in a 3D-Printer. A CT scan was performed on the phantom. The phantom itself served as ground-truth reference to ensure exact and reproducible catheter placement. A MediGuide® catheter was repeatedly tagged at selected positions to assess accuracy of point localization. The catheter was also used to acquire a MediGuide®-scaled geometry in the EnSite Velocity® electroanatomic mapping system. The acquired geometries (MediGuide®-scaled and EnSite Velocity®-scaled) were compared to a CT segmentation of the phantom to quantify concordance. Distances between landmarks were measured in the EnSite Velocity®- and MediGuide®-scaled geometry and the CT dataset for Bland-Altman comparison. The visualization of virtual MediGuide® catheter tips was compared to their corresponding representation on fluoroscopic cine-loops. Point localization accuracy was 0.5 ± 0.3 mm for MediGuide® and 1.4 ± 0.7 mm for EnSite Velocity®. The 3D accuracy of the geometries was 1.1 ± 1.4 mm (MediGuide®-scaled) and 3.2 ± 1.6 mm (not MediGuide®-scaled). The offset between virtual MediGuide® catheter visualization and catheter representation on corresponding fluoroscopic cine-loops was 0.4 ± 0.1 mm.The MediGuide® system shows a very high level of accuracy regarding localization reproducibility as well as spatial and visual accuracy, which can be ascribed to the magnetic field localization technology. The observed offsets between the geometry visualization and the real phantom are below a clinically relevant threshold.

Apixaban is increasingly used for stroke prevention in patients with atrial fibrillation. Data about the safety of left atrial radiofrequency ablation procedures under continuous apixaban therapy are lacking. We performed a matched-cohort study of patients undergoing left atrium ablation procedures for atrial fibrillation or left atrial flutter. For each patient on apixaban, 2 patients on phenprocoumon were matched by age, gender, and type of arrhythmia. The primary safety end point was a composite of bleeding, thromboembolic events, and death. We identified 105 consecutive patients (35 women; mean age 63 years) on apixaban and matched 210 phenprocoumon patients (70 women, mean age 64 years). The primary end point was met in 11 patients of the apixaban group and 26 patients of the phenprocoumon group (10.5% vs 12.3%, p = 0.71). Major bleeding complications occurred in 1 patient of the apixaban group and 1 patient of the phenprocoumon group (1% vs 0.5%, p >0.99). Minor bleeding complications were observed in 10 patients of the apixaban group and 25 patients of the phenprocoumon group (9.5% vs 11.9%, p = 0.61). No patient in either group experienced a thromboembolic event and no patient died. In patients on apixaban, no clinical variable was predictive for bleeding complications. Left atrial ablation procedures under continuous oral anticoagulation with apixaban are feasible and as safe as under continuous oral anticoagulation with phenprocoumon.

The role of dissociated pulmonary vein (DPV) activity after pulmonary vein isolation (PVI) is still poorly defined. We evaluated electrophysiological features and clinical impact on long-term outcome of DPV activity.A total of 243 patients (mean age 63 ± 11 years; 63% males) undergoing PVI for paroxysmal atrial fibrillation (AF) were included. DPV activity was defined as a residual low frequency irregular PV rhythm. Patients were divided into Group 1 (presence of DPV activity; n = 65) or Group 2 (absence of DPV activity; n = 178).Of 936 isolated PVs, 112 PVs (12%) showed DPV activity. DPV activity was observed more frequently in PVs identified as AF triggers (P = 0.026). During follow-up (mean 12 ± 7 months), 15 of 65 patients of Group 1 (23%) and 57 of 178 patients of Group 2 (32%) had an arrhythmia recurrence (P = 0.23). At linear regression analysis, no independent predictor for clinical recurrence was identified. During the repeat ablation, 62 of 72 patients (86%) showed a recovered PV conduction without difference between the 2 groups. Clinically, all patients of Group 1 with PV reconnection (n = 13/15) had a recurrence of paroxysmal AF. In Group 2, 5 of 52 patients with reconnected PV developed non-PV related arrhythmias.DPV activity occurred in 12% of PVs after PVI and was observed more frequently in PVs identified as AF triggers. DPV activity was not predictive for AF recurrence during follow-up. PV-left atrium reconnection involving PVs with DPV activity leads to AF.

Methods. 17 physicians, experienced in transvenous lead removal, performed a lead extraction manoeuvre of an ICD lead on a torso phantom. They were advised to stop traction only when further traction would be considered as harmful to the patient or when—based on their experience—a change in the extraction strategy was indicated. Traction forces were recorded with a digital precision gauge.Results. Median traction forces on the endocardium were 10.9 N (range from 3.0 N to 24.7 N and interquartile range from 7.9 to 15.3). Forces applied to the proximal end were estimated to be 10% higher than those measured at the tip of the lead due to a friction loss.Conclusion. A traction force of around 11 N is typically exerted during standard transvenous extraction of ICD leads. A traction threshold for a safe procedure derived from a pool of experienced extractionists may be helpful for the development of required adequate simulator trainings.

One of the great discoveries in cardiac electrophysiology was the recognition of the crucial role of pulmonary vein (PV) myocardial sleeves for the initiation of atrial fibrillation (AF). Based on this concept, catheter ablation aiming at electrical isolation of all pulmonary veins has become the routine approach for of paroxysmal AF. Another concept implies selective isolation only of arrhythmogenic PVs. Based on the most important studies dealing with both approaches, we describe pros and cons of selective compared to complete pulmonary vein isolation (PVI) and illustrate why selective PVI has not found widespread acceptance in the electrophysiologic community.