Feasibility and safety of left atrial access for ablation of atrial fibrillation in patients with persistent left superior vena cava.

BACKGROUND: In patients with persistent left superior vena cava (PLSVC) ablation procedures can be challenging. We sought to determine the feasibility and safety of left atrial ablations in patients with PLSVC, especially when PLSVC is unknown prior to the ablation procedure. METHODS AND RESULTS: In this retrospective analysis 15 adult patients (mean age 64.6 ± 14.5 years, 53.3% male) with PLSVC undergoing 27 ablation procedures for atrial fibrillation or left atrial flutter were included. In 5 (33.3%) patients PLSVC was only discovered during the procedure. Transseptal puncture (TSP) was declared "difficult" by the ablating physician in 13 of 27 (48.2%) procedures and was not successfully completed in the first attempt in two patients with known PLSVC. Once TSP was successfully completed, all relevant structures were reached both during mapping and ablation in all procedures independent of whether PLSVC was known prior to the procedure. One major complication (3.7%) occurred in 27 procedures in a patient with known PLSVC. In the patients with unknown PLSVC no complication occurred. CONCLUSION: In experienced hands, left atrial access and ablation in patients with PLSVC is feasible and safe, particularly with regard to patients in whom the PLSVC is unknown prior to the ablation procedure.

RF electrode-tissue coverage significantly influences steam pop incidence and lesion size.

BACKGROUND: Steam pops are a rare complication associated with radiofrequency (RF) ablation and are hard to predict. The aim of this study was to assess the influence of coverage between the RF ablation electrode and cardiac tissue on steam pop incidence and lesion size. METHODS AND RESULTS: An ex vivo model using porcine cardiac preparations and contact force sensing catheters was designed to perform RF ablations at different coverage levels between the RF electrode and cardiac tissue. During coverage level I, only the distal part of the ablation electrode was in contact with tissue. During coverage level II half of the ablation electrode, and during coverage level III the entire ablation electrode was embedded in tissue. RF applications (n = 60) at different coverage levels I-III were systematically performed using the same standardized ablation protocol. Ablations during coverage level III resulted in a significantly higher rate of steam pops (100%) when compared to ablations during coverage level II (10%) and coverage level I (0%), log rank p < .001. Coverage level I ablations resulted in significantly smaller lesion depths, diameters, and impedance drops when compared to higher coverage level ablations, p < .001. In the controlled ex vivo model, there was no difference in applied contact force or energy between different coverage levels. CONCLUSIONS: The level of coverage between RF electrode, cardiac tissue, and the surrounding fluid significantly influenced the incidence of steam pops in an ex vivo setup. Larger coverage between RF electrode and tissue resulted in significantly larger lesion dimensions.

Cardiac resynchronisation therapy in patients with left bundle branch block with residual conduction.

AIM: To evaluate whether left bundle branch block with residual conduction (rLBBB) is associated with worse outcomes after cardiac resynchronisation therapy (CRT). METHODS: All consecutive CRT implants at our institution between 2006 and 2013 were identified from our local device registry. Pre- and post-implant patient specific data were extracted from clinical records. RESULTS: A total of 690 CRT implants were identified during the study period. Prior to CRT, 52.2% of patients had true left bundle branch block (LBBB), 19.1% a pacing-induced LBBB (pLBBB), 11.2% a rLBBB, 0.8% a right bundle branch block (RBBB), and 16.5% had a nonspecific intraventricular conduction delay (IVCD) electrocardiogram pattern. Mean age at implant was 67.5 years (standard deviation [SD] = 10.6), mean left ventricular ejection fraction (LV EF) was 25.7% (SD = 7.9%), and mean QRS duration was 158.4 ms (SD = 32 ms). After CRT, QRS duration was significantly reduced in the LBBB (p < 0.001), pLBBB (p < 0.001), rLBBB (p < 0.001), RBBB (p = 0.04), and IVCD groups (p = 0.03). LV EF significantly improved in the LBBB (p < 0.001), rLBBB (p = 0.002), and pLBBB (p < 0.001) groups, but the RBBB and IVCD groups showed no improvement. There was no significant difference in mortality between the LBBB and rLBBB groups. LV EF post-CRT, chronic kidney disease, hyperkalaemia, hypernatremia, and age at implant were significant predictors of mortality. CONCLUSION: CRT in patients with rLBBB results in improved LV EF and similar mortality rates to CRT patients with complete LBBB. Predictors of mortality post-CRT include post-CRT LV EF, presence of CKD, hyperkalaemia, hypernatremia, and older age at implant.

Safety and outcome of very high-power short-duration ablation using 70 W for pulmonary vein isolation in patients with paroxysmal atrial fibrillation.

AIMS: Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) in patients with paroxysmal atrial fibrillation (PAF) is effective but hampered by pulmonary vein reconnection due to insufficient ablation lesions. High-power delivery over a short period of time (HPSD) in RFA is stated to create more efficient lesions. The aim of this study was to compare intraprocedural safety and outcome of HPSD ablation to conventional power settings in patients undergoing PVI for PAF. METHODS AND RESULTS: We included 197 patients with PAF that were scheduled for PVI. An ablation protocol with 70 W and a duration cut-off of 7 s at the anterior left atrium (LA) and 5 s at the posterior LA (HPSD group; n = 97) was compared to a conventional power protocol with 30-40 W for 20-40 s (standard group; n = 100) in terms of periprocedural complications and a 1-year outcome. The HPSD group showed significantly less arrhythmia recurrence during 1-year follow-up with 83.1% of patients free from atrial fibrillation compared to 65.1% in the standard group (P < 0.013). No pericardial tamponade, periprocedural thromboembolic complications, or atrio-oesophageal fistula occurred in either group. Mean radiofrequency time (12.4 ± 3.4 min vs. 35.6 ± 12.1 min) and procedural time (89.5 ± 23.9 min vs. 111.15 ± 27.9 min) were significantly shorter in the HPSD group compared to the standard group (both P < 0.001). CONCLUSION: High-power short-duration ablation demonstrated a comparable safety profile to conventional ablation. High-power short-duration ablation using 70 W for 5-7 s leads to significantly less arrhythmia recurrences after 1 year. Radiofrequency and procedural time were significantly shortened.

Early recurrence after pulmonary vein isolation is associated with inferior long-term outcomes: Insights from a retrospective cohort study.

AIMS: The aim of this retrospective cohort study was to assess the influence of early recurrence (ER) after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) on long-term outcomes and to identify clinical variables associated with ER. METHODS: We retrospectively collected clinical and procedural data from 1285 patients with paroxysmal AF who underwent PVI from 2011 to 2016. Kaplan-Meier, receiver operating characteristic (ROC) curve, logistic and Cox regression analyses were performed to analyze the influence of ER on long-term outcomes. RESULTS: ER was observed in 13% of patients. Kaplan-Meier analyses showed significantly different outcomes in 1285 patients with and without ER (49% vs 74%, log rank P < .01) and in 286 patients in the subgroup that underwent reablation (44% vs 79%, log rank P < .01). The hazard ratio (HR) of ER was 1.7 within 48 hours (5% of patients), 2.7 within 1 month (5%), 3.0 within 2 months (2%), and 6.4 within 3 months (1%) for late recurrence (LR), P < .01. ROC analysis (area under the curve [AUC] = 0.79) resulted in 70.3% sensitivity and 74.2% specificity for a 14-day blanking period, and 53.1% sensitivity and 85.5% specificity for a 30-day blanking period. Female patients (odds ratio [OR] 1.69, P < .01) and those with diabetes (OR 1.95, P = .01) were at higher risk for ER. CONCLUSIONS: ER is observed in a substantial number of patients with paroxysmal AF after PVI and has a continuous direct effect on LR according to the timing of ER. Randomized trials are required to assess the safety and effects of reablations in a shortened blanking period on long-term outcomes.

EP radiofrequency generators: Significant offsets between selected and delivered power?

INTRODUCTION: For radiofrequency (RF) ablation, the EP Shuttle® (Stockert GmbH, Freiburg, Germany), Ampere® (St. Jude Medical, St. Paul, MN, USA), and SmartAblate® (Biosense Webster, Diamond Bar, CA, USA) generator models are most frequently used in clinical practice. The aim of this study was to assess the correlation between selected and delivered RF power for different generators. METHODS AND RESULTS: In an experimental setup, ablation catheters were connected to the EP Shuttle® , Ampere® , and SmartAblate® generators. The power delivered by the generators was measured using a current converter and an oscilloscope. The selected power displayed on the generator was compared to the actually delivered power measured by the experimental setup (n = 800 measurements). The offsets between selected and delivered power increased significantly with impedance (EP Shuttle® ). For example, at a selected power of 30 W, the delivered power was 40.3 W (EP Shuttle® ), 30.1 W (Ampere® ), and 28.1 W (SmartAblate® ) at an impedance of 200 Ω. In addition, ablation lesions (n = 80) were created in ex vivo porcine cardiac muscle preparations. The resulting ablation lesion size was calculated in caliper measurements. When the EP Shuttle® generator was operated at 200 Ω, the resulting lesion size was significantly larger than at 100 Ω. There were no significant offsets between power delivery and lesion size when using the Ampere® or SmartAblate® generators. CONCLUSIONS: The Ampere® and SmartAblate® generator models deliver accurate power as selected by the user. The power delivered by the EP Shuttle® generator exceeds the selected power by up to 40% depending on impedance. The findings were confirmed in ex vivo porcine heart experiments and should be considered in clinical practice.

Catheter ablation of left atrial arrhythmias on uninterrupted oral anticoagulation with vitamin K antagonists: What is the relationship between international normalized ratio, activated clotting time, and procedure-related complications?

BACKGROUND: Ablation of atrial fibrillation (AF) on uninterrupted phenprocoumon reduces periprocedural thromboembolic and bleeding complications. Heparin is administered intraprocedurally to achieve activated clotting times (ACT) of 300-400 seconds. We investigated the effect of international normalized ratio (INR) on ACT and intraprocedural heparin requirements. Moreover, safety of a target ACT of 250-300 seconds was investigated. METHODS AND RESULTS: We studied 949 patients referred for AF or left atrial tachycardia ablation. Patients were divided into Group 1 (n = 249) with an INR <2 and Group 2 (n = 700) with an INR ≥2. Mean INR was 1.7 ± 0.13 in Group 1 and 2.3 ± 0.25 in Group 2. Baseline, mean, minimum and maximum ACT were significantly lower in Group 1 (138 ± 17 seconds vs. 145 ± 21 seconds; 281 ± 28 seconds vs. 288 ± 29 seconds; 251 ± 36 seconds vs. 258 ± 34 seconds; 307 ± 32 seconds vs. 316 ± 40 seconds; P <0.05). Intraprocedural heparin requirements adjusted to body weight were lower in Group 1 (127 ± 41 U/kg vs. 122 ± 40 U/kg). Weak correlations between INR and baseline, mean, minimum and maximum ACT as well as intraprocedural heparin requirements were observed. No differences regarding major or minor complications were found. INR and periprocedural anticoagulation parameters had no influence on major complications. No thromboembolic complications were observed in both groups with a target ACT value of 250-300 seconds. CONCLUSIONS: There is only a weak correlation between INR, intraprocedural ACT, and intraprocedural heparin requirements. Periprocedural target ACT of 250-300 seconds seems safe and does not increase periprocedural bleeding and thromboembolic complications in patients undergoing RF ablation on uninterrupted phenprocoumon therapy.

Evaluation of a new very low dose imaging protocol: feasibility and impact on X-ray dose levels in electrophysiology procedures.

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.

Sensor-Based Electromagnetic Navigation (Mediguide®): How Accurate Is It? A Phantom Model Study.

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.

Early arrhythmia recurrence after catheter ablation for persistent atrial fibrillation: is it predictive for late recurrence?

BACKGROUND: Early recurrence of atrial tachyarrhythmia (ERAT) is common after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF), but its clinical significance in patients with persistent AF remains unclear. We sought to determine the predictive value of ERAT for rhythm outcome after RFCA for persistent AF. METHODS: The study included 207 consecutive patients (mean age 66.4 ± 10.7 years, male 66.2%) with persistent and long-standing persistent AF undergoing de novo pulmonary vein isolation (± atrial substrate ablation). All patients remained off antiarrhythmic drugs. ERAT was defined as any atrial arrhythmia ≥ 30 s occurring within the first 30 days. Late recurrence (LR) was determined during follow-up visits scheduled 1, 3, 6 and 12 months post-ablation using 7-day Holter ECGs. RESULTS: ERAT occurred in 143/207 (69.1%) patients as AF (60%) or atrial tachycardia (40%) and was persistent in 82% of cases. During a median follow-up of 22.2 months, LR occurred significantly more often in patients with ERAT than in patients without ERAT (92.3 vs. 43.8%, P < 0.001). The only independent predictors for LR were ERAT (OR 16.8, 95% CI 6.184-45.797, P < 0.001) and intraprocedural termination to sinus rhythm (OR 0.052, 95% CI 0.003-0.851, P = 0.038). Extending the blanking period from 30 to 90 days did not impact LR rates. CONCLUSION: ERAT following ablation of persistent AF is strongly associated with late arrhythmia recurrence, which challenges the assumption that ERAT represents merely a transient phenomenon. While limiting the blanking period to 30 days seems justified, the benefit of early re-ablations remains to be addressed in future studies.

Deep sedation with propofol in patients undergoing left atrial ablation procedures-Is it safe?

Background: Catheter ablation for atrial fibrillation (AF) or left atrial tachycardia is well established. To avoid body movement and pain, sedative and analgesic agents are used. Objective: The aim was to investigate safety of sedation/anti-pain protocol administered by electrophysiology (EP) staff. Methods: A total of 3211 consecutive patients (61% male) undergoing left atrial ablation for paroxysmal AF (37.1%), persistent AF (35.3%) or left atrial tachycardia (27.6%) were included. Midazolam, fentanyl, and propofol were administered by EP staff. In case of respiratory depression, endotracheal intubation (eIT) or noninvasive ventilation (NIV) was implemented. Risk factors for eIT or NIV were analyzed. Results: Mean doses of propofol, midazolam, and fentanyl were 33.7 ± 16.7 mg, 3 ± 11.1 mg, and 0.16 ± 2.2 mg, respectively. Norepinephrine was administered in 396 of 3211 patients (12.3%) because of blood pressure drop (mean arterial pressure <60 mm Hg). NIV was necessary in 47 patients (1.5%) and eIT in 1 patient (0.03%). Procedure duration, high body mass index (BMI), high CHADS2-VASC2 score, high age, low glomerular filtration rate, diabetes mellitus, and low baseline oxygen saturation were associated with NIV or eIT. The only independent predictor for NIV/eIT was high BMI (>30.1 ± 9.0 kg/m2). Therefore, patients with a BMI of ≥30 had a 40% higher risk for the need of NIV/eIT during the procedure in our study. Conclusion: Sedation/anti-pain control including midazolam, propofol, and fentanyl administered by EP staff is safe, with only 1.53% requirement of NIV/eIT. High BMI (>30 kg/m2) emerged as an independent predictor for eIT/NIV.

Myocardial Minimal Damage After Rapid Ventricular Pacing - the prospective randomized multicentre MyDate-Trial.

Therapy of choice for the primary and secondary prevention of sudden cardiac death is the implantation of an implantable cardioverter defibrillator (ICD). Whereas appropriate and inappropriate ICD shocks lead to myocardial microdamage, this is not known for antitachycardia pacing (ATP). In total, 150 ICD recipients (66 ± 12 years, 81.3% male, 93.3% primary prevention, 30.0% resynchronization therapy) were randomly assigned to an ICD implantation with or without intraoperative ATP. In the group with ATP, the pacing maneuver was performed twice, each time applying 8 impulses à 6 Volt x 1.0 milliseconds to the myocardium. High sensitive Troponin T (hsTnT) levels were determined prior to the implantation and thereafter. There was no significant difference in the release of hsTnT between the two randomization groups (delta TnT without ATP in median 0.010 ng/ml [min. -0.016 ng/ml-max. 0.075 ng/ml] vs. with ATP in median 0.013 ng/ml [min. -0.005-0.287 ng/ml], p = 0.323). Setting a hsTnT cutoff of 0.059 ng/dl as a regularly augmented postoperative hsTnT level, no relevant difference between the two groups regarding the postoperative hsTnT levels above this cutoff could be identified (without ATP n = 10 [14.7%] vs. with ATP n = 16 [21.9%], p = 0.287). There was no significant difference in the release of high sensitive Troponin between patients without intraoperative ATP compared to those with intraoperative ATP. Hence, antitachycardia pacing does not seem to cause significant myocardial microdamage. This may further support its use as a painless and efficient method to terminate ventricular tachycardia in high-risk patients.

Patients with pacemakers or defibrillators do not need to worry about e-Cars: An observational study.

BACKGROUND: Electric cars are increasingly used for public and private transportation and represent possible sources of electromagnetic interference (EMI). Potential implications for patients with cardiac implantable electronic devices (CIED) range from unnecessary driving restrictions to life-threatening device malfunction. This prospective, cross-sectional study was designed to assess the EMI risk of electric cars on CIED function. METHODS: One hundred and eight consecutive patients with CIEDs presenting for routine follow-up between May 2014 and January 2015 were enrolled in the study. The participants were exposed to electromagnetic fields generated by the four most common electric cars (Nissan Leaf, Tesla Model S, BMW i3, VW eUp) while roller-bench test-driving at Institute of Automotive Technology, Department of Mechanical Engineering, Technical University, Munich. The primary endpoint was any abnormalities in CIED function (e.g. oversensing with pacing-inhibition, inappropriate therapy or mode-switching) while driving or charging electric cars as assessed by electrocardiographic recordings and device interrogation. RESULTS: No change in device function or programming was seen in this cohort which is representative of contemporary CIED devices. The largest electromagnetic field detected was along the charging cable during high current charging (116.5 µT). The field strength in the cabin was lower (2.1-3.6 µT). CONCLUSIONS: Electric cars produce electromagnetic fields; however, they did not affect CIED function or programming in our cohort. Driving and charging of electric cars is likely safe for patients with CIEDs.

Atrial fibrillation ablation in adults with congenital heart disease on uninterrupted oral anticoagulation is safe and efficient.

BACKGROUND: The prevalence of atrial fibrillation (AF) is significantly higher in adults with congenital heart disease (ACHD) compared to patients without congenital heart disease (CHD). As AF in ACHD patients might have significant hemodynamic consequences, rhythm control is particularly desirable but rarely achieved by antiarrhythmic drugs. The aim of this study was to investigate safety and long-term outcome of AF ablation in ACHD patients. METHODS: All ACHD patients (n = 46) that underwent AF ablation at our centre from 2013 to 2017 were included in the study. CHD was classified as simple (46%), moderate (41%) or complex (13%). The majority of patients (61%) suffered from persistent AF (paroxysmal AF 39%). Persistent AF was present in 57% of patients with simple, in 58% of patients with moderate and 83% of patients with complex CHD. All patients underwent radiofrequency (RF) ablation on uninterrupted oral anticoagulation. Pulmonary vein isolation (PVI) was performed in patients with paroxysmal AF, whereas patients with persistent AF underwent PVI and ablation of complex fractionated atrial electrograms (CFAE). RESULTS: No major complications occurred. Single-procedure success after 18 months off antiarrhythmic drugs was 61% for paroxysmal AF and 29% for persistent AF (p = 0.003). Multiple procedures (mean 2.1 ± 1.4) increased long-term success to 82% for paroxysmal AF and 48% for persistent AF (p = 0.05). Long-term ablation success was 64% for simple, 62% for moderate and 50% for complex CHD patients. CONCLUSIONS: AF ablation in ACHD patients is feasible and safe regardless of CHD complexity. Success rates in patients with paroxysmal AF are high and comparable to patients without CHD. In ACHD patients with persistent AF, success rates of ablation are markedly reduced which might be due to a different and/or more extensive (bi-)atrial substrate. In the cohort of complex ACHD patients with persistent AF as the dominant AF type, long-term success of AF ablation is limited.

Incidence of magnet mode in patients with implantable cardioverter defibrillators.

PURPOSE: To determine the current incidence of antitachycardia therapy suspension due to magnet reversion in patients with implantable cardioverter defibrillators (ICDs). METHODS: From March 2012 to September 2018, all St. Jude Medical ICD interrogations performed at the Deutsches Herzzentrum München were screened for stored events of antitachycardia therapy suspension caused by static magnetic fields (flux densities ≥ 1 mT as defined in St. Jude Medical ICDs) affecting the giant magnetoresistance (GMR) sensor. Intentional ICD deactivation or inappropriate magnet application in the hospital was classified as non-environmental electromagnetic interference (EMI) whereas in the case of any other stored magnet reversion, the event was classified as presumably environmental EMI. RESULTS: Data from 201 St. Jude Medical ICD patients (mean age 62 ± 24 years, 165 males/36 females) were included in the analysis. ICD interrogations occurred at a mean follow-up of 25.1 months ± 15.6 months and summed up to a total of 464 patient-years of follow-up. A total number of 43 magnet reversion events were detected in 21 patients. Thirty-two events in 13 patients were presumably related to environmental EMI sources. Suspension of antitachycardia therapy only occurred in a temporary fashion. None of the patients experienced any ventricular tachyarrhythmia during ICD inhibition. The incidence of antitachycardia therapy suspension due to magnet reversion related to presumably environmental EMI sources was 6.9% per patient and year. CONCLUSION: Although none of the patients experienced any harmful event, antitachycardia therapy suspension due to magnet reversion is a common issue. Patients should be well-educated about potential EMI sources as well as trained in handling them.

The incidence, indications and predictors of acute pacemaker implantation after ablation of persistent atrial fibrillation.

INTRODUCTION: Patients with persistent atrial fibrillation (AF) may additionally suffer from a concealed sinus node disease. We sought to determine the incidence, indications and predictors of acute pacemaker [PM] implantation within 1 week after the ablation of persistent AF. METHODS AND RESULTS: We performed a retrospective analysis of patients, who had had an ablation of persistent AF at our center. Between 01/2011 and 08/2016, 1234 patients (mean age 65 ± 10 years, 66.7% male) without prior PM implantation underwent an ablation of persistent AF. Pulmonary vein isolation (PVI) was performed in 1158 (93.8%), the additional ablation of complex fractionated atrial electrograms (CFAE) in 1109 (89.9%) and linear ablation in 524 (42.5%) patients. Temporary cardiac pacing was necessary in 27 (2.2%) patients. The temporary PM was removed in 15 patients (1.2%) because sinus node recovered after a median of 1.0 (minimum 0.1-maximum 2.0) day. The remaining 12 (1.0%) patients required the implantation of a permanent PM. Another 13 (1.1%) patients required permanent PM implantation without prior temporary pacing. In a multivariable regression model, age [OR 1.07 (1.02-1.12), p = 0.006], sinus pauses prior to ablation [OR 7.97 (2.36-26.88), p = 0.001] and atria with low voltage [OR 2.83 (1.31-6.11), p = 0.008] were identified as significant predictors for acute cardiac pacing. CONCLUSION: Acute cardiac pacing within 1 week after the ablation of persistent AF was necessary in 40 (3.2%) patients. Age, sinus pauses in history prior to ablation and the existence of low-voltage areas in the atria were identified as relevant risk factors.

The impact of multipole pacing on left ventricular function in patients with cardiac resynchronization therapy - A real-time three-dimensional echocardiography approach.

BACKGROUND: Cardiac resynchronization therapy (CRT) is standard of care in heart failure (HF), however this technique is associated with a non-responder rate of 30%. Multipole pacing (MPP) with a quadripolar lead may optimize CRT and responder rate by creating two electrical wave fronts in the left ventricular (LV) myocardium simultaneously in order to reduce mechanical dyssynchrony. The objective of this study was to investigate the acute impact of MPP on LV function by assessing systolic dyssynchrony index (SDI) and left ventricular ejection fraction (LVEF) via real-time three-dimensional echocardiography (RT3DE). METHODS: In 41 consecutive patients (87.8% male; mean age 66.0 ±â€¯12.7 years) who received CRT defibrillators with a quadripolar LV lead, RT3DE datasets were acquired the day after implantation under the following pacing configurations: Baseline AAI, conventional biventricular pacing using distal or proximal LV poles and MPP. Datasets were analyzed in paired samples evaluating SDI and LVEF depending on programmed pacing modality. RESULTS: MPP resulted in statistically significant reduction of SDI compared to baseline (6.3%; IQR 4.4-7.8 and 9.9%; IQR 8.0-12.7; p < 0.001) and to conventional biventricular pacing using distal (7.6%; IQR 6.5-9.1; p < 0.001) or proximal (7.4%; IQR 6.2-8.8; p < 0.001) LV poles respectively. MPP yielded significant increase in LVEF compared to baseline (30.6%; IQR 25.8-37.5 and 27.2%; IQR 21.1-33.6; p < 0.001) and to conventional biventricular pacing configuration with distal (28.1%; IQR 22.1-34.5; p < 0.001) or proximal (28.6%; IQR 23.2-34.9; p < 0.001) LV poles respectively. CONCLUSIONS: Multipole pacing improves mechanical dyssynchrony of the left ventricular myocardium as assessed by SDI and LVEF.

Safety of Uninterrupted Periprocedural Edoxaban Versus Phenprocoumon for Patients Who Underwent Left Atrial Catheter Ablation Procedures.

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.

Right Bundle Branch Block-Like Pattern During Uncomplicated Right Ventricular Pacing and the Effect of Pacing Site.

Right bundle branch block (RBBB) configuration is an unexpected finding during right ventricular (RV) pacing that raises the suspicion of inadvertent left ventricular lead positioning. The aim of this study was to evaluate the prevalence of paced RBBB pattern in relation to RV lead location. This is a secondary analysis of a prospective, multicenter study, which randomized implantable cardioverter defibrillator recipients to an apical versus midseptal defibrillator lead positioning. A 12-lead electrocardiogram was recorded during intrinsic rhythm and RV pacing. Paced RBBB-like pattern was defined as positive (>0.05 mV) net amplitude of QRS complex in leads V1 and/or V2. In total, 226 patients (65.6 ± 12.0 years, 20.8% women, 53.1% apical site) were included in the study. The prevalence of paced RBBB pattern in the total population was 15.5%. A significantly lower percentage of patients in the midseptal group demonstrated RBBB-type configuration during RV pacing compared with the apical group (1.9% vs 27.5%, p <0.001). Baseline RBBB, prolonged QRS duration during intrinsic rhythm, and reduced ejection fraction were not associated with increased likelihood of paced RBBB. In the subgroup of patients with RBBB type during pacing, 91.4% of patients had a paced QRS axis from -30° to -90°, whereas 100% of patients displayed a negative QRS vector at lead V3. In conclusion, RBBB configuration is encountered in a considerable percentage of device recipients during uncomplicated RV pacing. Midseptal lead positioning is associated with significantly lower likelihood of paced RBBB pattern compared with apical location.