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Background The association of epicardial adipose tissue (EAT) and its metabolic activity with atrial fibrillation (AF) is an area of active investigation. Left atrial (LA) enhancing EAT (e-EAT) at cardiac CT may be a noninvasive surrogate marker for the metabolic activity of EAT. Purpose To determine the relationship between LA e-EAT and recurrence after AF ablation. Materials and Methods In a secondary analysis of a prospective registry of consecutive patients (from July 2018 to December 2019) undergoing first AF ablation, total and LA EAT were segmented on preprocedural noncontrast- and contrast-enhanced cardiac CT scans. LA e-EAT volume fraction was defined as the LA EAT volume difference between the noncontrast- and contrast-enhanced scan divided by the total LA EAT volume on the noncontrast-enhanced scan (threshold values, -15 HU to -195 HU). Continuous variables were compared between groups by using the Mann-Whitney

Aims The aim of the study was to compare the 1-year efficacy and safety of a novel cryoballoon (NCB) ablation system (POLARx; Boston Scientific) for pulmonary vein isolation (PVI) compared with the standard cryoballoon (SCB) system (Arctic Front, Medtronic). Methods and results Consecutive patients with atrial fibrillation (AF) undergoing PVI using the NCB and the SCB at two centres were included. We report 1-year efficacy after 12 months, short-term safety and hospitalizations within the blanking period, and predictors for AF recurrence. In case of repeat procedures, pulmonary vein (PV) reconnection patterns were characterized. Eighty patients (age 66 ± 10 years, ejection fraction 57 ± 10%, left atrial volume index 39 ± 13 mL/m2, paroxysmal AF in 64%) were studied. After a single procedure and a follow-up of 12 months, 68% in the NCB group and 70% in the SCB group showed no recurrence of AF/atrial tachycardias (P = 0.422). One patient in the NCB group suffered a periprocedural stroke with full recovery. There were no differences regarding hospitalizations during follow-up between the groups. PV reconnection observed during 12 repeat procedures (4 NCB, 8 SCB) pattern was comparable between the groups with more reconnections in the right-sided compared with the left-sided PVs. Conclusion In this multicentre study comparing two currently available cryoballoon ablation systems for PVI, no differences were observed in the efficacy and safety during a follow-up of 12 months.

Introduction: Contact force-sensing catheters are widely used for ablation of cardiac arrhythmias. They allow quantification of catheter-to-tissue contact, which is an important determinant for lesion formation and may reduce the risk of complications. The accuracy of these sensors may vary across the measurement range, catheter-to-tissue angle, and amongst manufacturers and we aim to compare the accuracy and reproducibility of four different force sensing ablation catheters. Methods: A measurement setup containing a heated saline water bath with an integrated force measurement unit was constructed and validated. Subsequently, we investigated four different catheter models, each equipped with a unique measurement technology: Tacticath Quartz (Abbott), AcQBlate Force (Biotronik/Acutus), Stablepoint (Boston Scientific), and Smarttouch SF (Biosense Webster). For each model, the accuracy of three different catheters was measured within the range of 0-60 grams and at contact angles of 0°, 30°, 45°, 60°, and 90°. Results: In total, 6685 measurements were performed using 4x3 catheters (median of 568, IQR 511-606 measurements per catheter). Over the entire measurement-range, the force measured by the catheters deviated from the real force by the following absolute mean values: Tacticath 1.29g ±0.99g, AcQBlate Force 2.87g ±2.37g, Stablepoint 1.38g ±1.29g, and Smarttouch 2.26g ±2.70g. For some models, significant under- and overestimation of >10g were observed at higher forces. Mean absolute errors of all models across the range of 10-40g were Conclusion: Contact measured by force-sensing catheters is accurate with 1-3g deviation within the range of 10g to 40g. Significant errors can occur at higher forces with potential clinical consequences.

Background: A pace and ablate strategy may be performed in refractory atrial fibrillation with rapid ventricular response. Objective: We aimed to assess sex-related differences in patient selection and clinical outcomes after pace and ablate. Methods: In a retrospective multicentre study, patients undergoing AV junction ablation were studied. Sex-related differences in baseline characteristics, all-cause mortality, heart failure (HF) hospitalizations, and device-related complications were assessed. Results: Overall, 513 patients underwent AV junction ablation (median age 75 years, 50% men). At baseline, men were younger (72 vs. 78 years, p < 0.001), more frequently had non-paroxysmal AF (82% vs. 72%, p = 0.006), had a lower LVEF (35% vs. 55%, p < 0.001) and more frequently had cardiac resynchronization therapy (75% vs. 25%, p < 0.001). Interventional complications were rare in both groups (1.2% vs. 1.6%, p = 0.72). Patients were followed for a median of 42 months in survivors (IQR 22–62). After 4 years of follow-up, the combined endpoint of all-cause death or HF hospitalization occurred more often in men (38% vs. 27%, p = 0.008). The same was observed for HF hospitalizations (22% vs. 11%, p = 0.021) and all-cause death (28% vs. 21%, p = 0.017). Sex category remained an independent predictor of death or HF hospitalization after adjustment for age, LVEF and type of stimulation. Lead-related complications, infections, and upgrade to ICD or CRT occurred in 2.1%, 0.2% and 3.5% of patients, respectively. Conclusions: Pace and ablate is safe with a need for subsequent device-related re-interventions in 5.8% over 4 years. We found significant sex-related differences in patient selection, and women had a more favourable clinical course after AV junction ablation.

Aims Leadless cardiac pacemaker (PM) implantation differs from conventional PM implantation. While the procedure has been considered safe, recent real-world data raised concerns about the learning curve of new operators and their implantation quality. The goal of this study was to investigate the influence of the first operator’s experience on leadless PM implantation quality and procedural efficiency. Methods and results We performed a bicentric analysis of all Micra TPS™ implantations in two large tertiary referral hospitals. We assessed both leadless PM implantation quality based on the absence of complications (requiring intervention or prolonged hospitalization), good electrical performance (pacing threshold ≤ 1.5 V/0.24 ms, R-wave amplitude > 5 mV), and acceptable fluoroscopy duration ( Conclusion The operator’s learning curve is a critical factor for leadless PM implantation quality and procedural efficiency.

Background: Hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD) and athletes’ heart share an increased prevalence of atrial fibrillation. Atrial cardiomyopathy in these patients may have different characteristics and help to distinguish these conditions. Methods: In this single-center study, we prospectively collected and analyzed electrocardiographic (12-lead ECG, signal-averaged ECG (SAECG), 24 h Holter ECG) and echocardiographic data in patients with HCM and HHD and in endurance athletes. Patients with atrial fibrillation were excluded. Results: We compared data of 27 patients with HCM (70% males, mean age 50 ± 14 years), 324 patients with HHD (52% males, mean age 75 ± 5.5 years), and 215 endurance athletes (72% males, mean age 42 ± 7.5 years). HCM patients had significantly longer filtered P-wave duration (153 ± 26 ms) and PR interval (191 ± 48 ms) compared to HHD patients (144 ± 16 ms, p = 0.012 and 178 ± 31, p = 0.034, respectively) and athletes (134 ± 14 ms, p = 0.001 and 165 ± 26 ms, both p < 0.001, respectively). HCM patients had a mean of 4.9 ± 16 premature atrial complexes per hour. Premature atrial complexes per hour were significantly more frequent in HHD patients (27 ± 86, p < 0.001), but not in athletes (2.7 ± 23, p = 0.639). Left atrial volume index (LAVI) was 43 ± 14 mL/m2 in HCM patients and significantly larger than age- and sex-corrected LAVI in HHD patients 30 ± 10 mL/m2; p < 0.001) and athletes (31 ± 9.5 mL/m2; p < 0.001). A borderline interventricular septum thickness ≥13 mm and ≤15 mm was found in 114 (35%) HHD patients, 12 (6%) athletes and 3 (11%) HCM patients. Conclusions: Structural and electrical atrial remodeling is more advanced in HCM patients compared to HHD patients and athletes.

Hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD) and athletes' heart share an increased prevalence of atrial fibrillation. Atrial cardiomyopathy in these patients may have different characteristics and help to distinguish these conditions.In this single-center study, we prospectively collected and analyzed electrocardiographic (12-lead ECG, signal-averaged ECG (SAECG), 24 h Holter ECG) and echocardiographic data in patients with HCM and HHD and in endurance athletes. Patients with atrial fibrillation were excluded.We compared data of 27 patients with HCM (70% males, mean age 50 ± 14 years), 324 patients with HHD (52% males, mean age 75 ± 5.5 years), and 215 endurance athletes (72% males, mean age 42 ± 7.5 years). HCM patients had significantly longer filtered P-wave duration (153 ± 26 ms) and PR interval (191 ± 48 ms) compared to HHD patients (144 ± 16 ms,Structural and electrical atrial remodeling is more advanced in HCM patients compared to HHD patients and athletes.

Aims To validate the performance of a multipolar pulsed-field ablation (PFA) catheter compared to a standard pentaspline 3D-mapping catheter for endpoint assessment of pulmonary vein isolation (PVI). PFA for PVI using single-shot devices combines the benefits of high procedural efficacy and safety. A newly available multipolar PFA catheter allows real-time recording of pulmonary vein (PV) signals during PVI. Methods and results Patients undergoing first PVI using PFA with the standard ablation protocol (eight applications per PV) were studied. Entrance and exit block (10 V/2 ms) were assessed using the PFA catheter. Subsequently, a high-density 3D electroanatomical bipolar voltage map (3D-EAM) was constructed using a standard pentaspline 3D-mapping catheter. Additional PFA applications were delivered only after confirmation of residual PV connection by 3D-EAM. In 56 patients, 213 PVs were targeted for ablation. Acute PVI was achieved in 100% of PVs: in 199/213 (93%) PVs with the standard ablation protocol alone and in the remaining 14 PVs after additional PFA applications. The accuracy of PV assessment with the PFA catheter after the standard ablation protocol was 91% (194/213 veins). In 5/213 (2.3%) PVs, the PFA catheter incorrectly indicated PV-isolation. In 14/213 (6.6%), the PFA catheter incorrectly indicated residual PV-conduction due to high-output pace-capture. Lowering the output to 5 V/1 ms reduced this observation to 0.9% (2/213) and increased the overall accuracy to 97% (206/213). Conclusion A novel multipolar PFA catheter allows reliable endpoint assessment for PVI. Due to its design, far-field sensing and high-output pace-capture can occur. Lowering the pacing output increases the accuracy from 91 to 97%.

INTRODUCTION Conventional transvenous pacemaker leads may interfere with the tricuspid valve leaflets, tendinous chords and papillary muscles, resulting in significant tricuspid valve regurgitation (TR). Leadless pacemakers (LLPMs) theoretically cause less mechanical interference with the tricuspid valve apparatus. However, data on TR after LLPM implantation are sparse and conflicting. Our goal was to investigate the prevalence of significant TR before and after LLPM implantation. METHODS Patients who received a leadless LLPM (Micra™ TPS, Medtronic, US) between 05/2016 and 05/2021 at our center were included in this observational study if they had at least a pre- and postinterventional echocardiogram (TTE). The evolution of TR severity was assessed. Following a systematic literature review on TR evolution after implantation of a LLPM, data were pooled in a random-effects meta-analysis. RESULTS We included 69 patients (median age 78 years [interquartile range (IQR) 72-84 years], 26% women). Follow-up duration between baseline and follow-up TTE was 11.4 months (IQR 3.5-20.1 months). At follow-up, overall TR severity was not different compared to baseline (p=0.49). Six patients (9%) had new significant TR during follow-up after LLPM implantation, whereas TR severity improved in seven patients (10%). In the systematic review, we identified seven additional articles that investigated the prevalence of significant TR after LLPM implantation. The meta-analysis based on 297 patients failed to show a difference in significant TR before and after LLPM implantation (risk ratio 1.22, 95%-CI 0.97-1.53, p=0.11). CONCLUSION To date, there is no substantial evidence for a significant change in TR after implantation of a LLPM. This article is protected by copyright. All rights reserved.

Background: The prevalence of atrial fibrillation (AF) is high in older patients. The present study aimed to estimate the age and sex specific prevalence of clinical and screen-detected atrial fibrillation (AF) in hospitalized patients. Methods: The STAR-FIB cohort study was a prospective cohort study recruiting participants from a large source population of hospitalized patients aged 65–84 years. The estimated size of the source population was 26,035 (95% CI 25,918–26,152), and 795 consenting patients without clinical AF were included in the cohort study after stratification by sex and age (49.2% females, mean age 74.7 years). Patients in the cohort study underwent three seven-day Holter ECGs in intervals of two months to screen for AF. Results: In the source population, the estimated prevalence of clinical AF was 22.2% (95% CI 18.4–26.1), 23.8% for males (95% CI 20.9–26.6) and 19.8% for females (95% CI 17.3–22.4, p for difference between sexes, 0.004). There was a linear trend for an increase in the prevalence of clinical AF with increasing age, overall and in both sexes. In the cohort study, AF was newly diagnosed in 38 patients, for an estimated prevalence of screen-detected AF of 4.9% overall (95% CI 3.3–6.6), 5.5% in males (95% CI 3.2–7.8) and 4.0% in females (95% CI 2.0–6.0, p for difference between sexes, 0.041). The estimated prevalence of screen-detected AF in the source population was 3.8% overall, 4.2% in males and 3.2% in females. Conclusion: In a large hospital-based patient population aged 65–84 years, the prevalence of clinical AF and of screen-detected AF was 22.2% and 3.8%, respectively, and significantly higher in males than females.

Aims Catheter ablation for atrial fibrillation (AF) is increasingly performed. Both clinical risk factors as well as the AF phenotype have been shown to influence ablation outcomes. The inter-relationship of the two however is incompletely understood. Methods In a retrospective analysis of a prospective registry of patients undergoing a first pulmonary vein isolation, the association of 8 predefined clinical risk factors (age >70 years, female gender, hypertension, BMI >30 kg/m2, coronary artery disease, heart failure, chronic kidney disease (CKD; eGFR Results Overall, 715 patients were enrolled (median age 63 years, 27% females, 69% paroxysmal AF). The prevalence of obesity, hypertension, heart failure and CKD was significantly higher in persistent AF, while female gender was more prevalent in paroxysmal AF. After 2 years of follow-up, overall freedom from recurrence was 46%, and was higher in paroxysmal AF compared to persistent AF (54.1% vs. 29.1%, p Conclusion Clinical risk factors predict outcome after pulmonary vein isolation in patients with paroxysmal, but not persistent AF. This is likely due to a strong association of those risk factors with the occurrence of persistent AF. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

INTRODUCTION Diaphragmatic myopotential oversensing (dMPO) by implantable cardioverter defibrillators (ICDs) is thought to be a rare condition that can be misdiagnosed as lead failure and lead to unnecessary lead replacement. We observed several cases of dMPO in patients with Sorin/LivaNova ICDs (MicroPort Sci.). We sought to systematically assess the incidence of dMPO in patients with Sorin/LivaNova ICDs. METHODS AND RESULTS A predefined number of 100 consecutive patients with Sorin/LivaNova ICDs were prospectively included in the device clinic of our center. Stored arrhythmia episodes were checked for spontaneous dMPO. In addition, we performed provocation maneuvers by Valsalva. At least one episode of spontaneous or provoked dMPO was seen in 12 (12%) of the 100 patients included in the study (86% males, median age: 66 years). Nine of 89 patients (10%) with true bipolar and 3 of 11 patients (27%) with integrated bipolar sensing configuration were affected. Spontaneous dMPO was observed in 7 of 58 patients (12%) with sensitivity programmed to 0.4 mV and in 2 of 42 patients (5%) with sensitivity programmed to 0.6 mV (not significant). In three patients, dMPO could be provoked with no spontaneous episodes recorded. In two nonpacemaker-dependent patients with a CRT-D, ventricular pacing was temporarily inhibited. No antitachycardia therapy was triggered by dMPO in any patient. CONCLUSIONS DMPO is frequent in patients with Sorin/LivaNova ICDs, especially with sensitivity programmed to 0.4 mV. It also frequently occurs with true bipolar sensing configuration. DMPO should not be misinterpreted as lead failure to avoid unnecessary lead replacement.

OBJECTIVES Our goal was to analyse the implantation and outcome of thoracoscopic epicardial leads after a failed endovascular approach or follow-up (FU) complications after endovascular implantation. METHODS We reviewed the records of patients with failed endovascular left ventricular (LV) lead placement or complications during FU, who were subsequently referred to cardiac surgeons for treatment with thoracoscopic LV lead implantation. We analysed the reasons for endovascular failure; the indications for the surgical procedures; and the clinical, echocardiographic and device FU results. RESULTS Between 2010 and 2013, a total of 23 patients were included. Among them, 17 of the patients had no previous cardiothoracic surgery, 13 (76%) had successful video-assisted thoracoscopy (VAT) LV lead implantation, 3 (18%) had a conversion to thoracotomy and 1 (6%) failed. Of the 6 patients with prior cardiothoracic surgery, 2 (33%) had VAT only, 3 (50%) had primary thoracotomies and 1 (17%) had a conversion. Two major complications occurred. The reasons for LV endovascular lead failure were subclavian vein occlusion (n = 2), implant failure (n = 13) and complications during the FU period (n = 8). FU information was available for 20 patients: 17 (85%) had improved symptoms. The median FU period was 33 months. A total of 78% of patients were in New York Heart Association (NYHA) functional class III–IV before the operation; 30% were in NYHA functional class III–IV at the last FU examination. The left ventricular ejection fraction increased from 25% before surgery to 31% at the last FU examination. Overall, sensing and pacing threshold values remained stable over time. In 1 patient, lead revision was necessary due to an increase in the pacing threshold. CONCLUSIONS VAT implantation of LV leads had an excellent response rate with an improvement in NYHA functional class and left ventricular ejection fraction. The lead measurements were mainly stable over time.

Contemporary cardiac implantable electronic devices such as pacemakers or event recorders are powered by primary batteries. Device replacement due to battery depletion may cause complications and is costly. The goal of energy harvesting devices is to power the implant with energy from intracorporeal power sources such as vibrations and blood flow. By replacing primary batteries with energy harvesters, reinterventions can be avoided and the size of the total device might be reduced. This paper introduces a device with a lever, which is deflected by the blood stream within the right ventricular outflow tract (RVOT), an attractive site for cardiac pacing. The resulting torque is converted to electrical energy by an electromagnetic mechanism. The blood flow harvester weighs 6.4 g and has a volume of 2 cm3, making the harvester small enough for catheter implantation. It was tested in an experimental setup mimicking flow conditions in the RVOT. The blood flow harvester generated a mean power of 14.39 ± 8.38 μW at 60 bpm (1 Hz) and up to 82.64 ± 17.14 μW at 200 bpm (3.33 Hz) during bench experiments at 1 m/s peak flow velocity. Therefore, it presents a viable alternative to power batteryless and leadless cardiac pacemakers.

Funding Acknowledgements Type of funding sources: None. Background A pace & ablate strategy may be performed in cases of severe refractory atrial arrhythmias. Purpose We aimed to assess gender related differences in patient selection and clinical outcomes after pace & ablate. Methods In a retrospective multicenter study, patients undergoing AV-junction-ablation between 2011 and 2019 were studied. Gender-related differences in terms of baseline characteristics, device-related complications, heart failure (HF) hospitalisations and death were assessed. Results Overall, 513 patients underwent AV-junction-ablation (median age 75 years, 50% males). At baseline, male patients were younger (72 vs. 78 years, p Conclusion A Pace & Ablate strategy is safe and results in improvement of EHRA class and LVEF in a substantial number of patients. We found significant gender differences in patient selection for pace & ablate. Female patients had a more favorable clinical course after AV-junction-ablation, which was independent of age, EF and type of stimulation. Abstract Figure. Comb. endpoint of death or heart failure

INTRODUCTION Chemical ablation by retrograde infusion of ethanol into the vein of Marshall (VOM-EI) can facilitate the achievement of mitral isthmus block. This study sought to describe the efficacy and safety of this technique. METHODS AND RESULTS Twenty-two consecutive patients (14 males, median age 71 years) with attempted VOM-EI for mitral isthmus ablation were included in the study. VOM-EI was successfully performed with a median of 4���ml of 96% ethanol in 19 patients (86%) and the mitral isthmus was successfully blocked in all (100%). Touch up endocardial and/or epicardial ablation after VOM-EI was necessary for 12 patients (63%). Perimitral flutter was present in 12 patients (63%) during VOM-EI and terminated or slowed by VOM-EI in 4 and 3 patients, respectively. The low-voltage area of the mitral isthmus region increased from 3.1���cm2 (interquartile range [IQR] 0-7.9) before to 13.2���cm2 (IQR: 8.2-15.0) after VOM-EI and correlated significantly with the volume of ethanol injected (p���=���.03). Median high-sensitive cardiac troponin-T increased significantly from 330���ng/L (IQR: 221-516) the evening of the procedure to 598���ng/L (IQR: 382-769; p���=���.02) the following morning. A small pericardial effusion occurred in three patients (16%), mild pericarditis in one (5%), and uneventful VOM dissection in two (11%). After a median follow-up of 3.5 months (IQR: 3.0-11.0), 10 of 18 patients (56%) with VOM-EI and available follow-up had arrhythmia recurrence. Repeat ablation was performed in five patients (50%) and peri-mitral flutter diagnosed in three (60%). CONCLUSION VOM-EI is feasible, safe, and effective to achieve acute mitral isthmus block.

AIMS OF THE STUDY Anticoagulation of patients with screen-detected atrial fibrillation may prevent ischaemic strokes. The STAR-FIB study programme aims to determine the age- and sex-specific prevalence of silent atrial fibrillation and to develop a clinical prediction model to identify patients at risk of undiagnosed atrial fibrillation in a hospitalised patient population. METHODS The STAR-FIB study programme includes a prospective cohort study and a case-control study of hospitalised patients aged 65–84 years, evenly distributed for both age and sex. We recruited 795 patients without atrial fibrillation for the cohort study (49.2% females; median age 74.8 years). All patients had three serial 7-day Holter ECGs to screen for silent atrial fibrillation. The primary endpoint will be any episode of atrial fibrillation or atrial flutter of ≥30 seconds duration. The age- and sex-specific prevalence of newly diagnosed atrial fibrillation will be estimated. For the case-control study, 120 patients with paroxysmal atrial fibrillation were recruited as cases (41.7% females; median age 74.6 years); controls will be randomly selected from the cohort study in a 2:1 ratio. All participants in the cohort study and all cases were prospectively evaluated including clinical, laboratory, echocardiographic and electrical parameters. A clinical prediction model for undiagnosed atrial fibrillation will be derived in the case-control study and externally validated in the cohort study. CONCLUSIONS The STAR-FIB study programme will estimate the age- and sex-specific prevalence of silent atrial fibrillation in a hospitalised patient population, and develop and validate a clinical prediction model to identify patients at risk of silent atrial fibrillation.

Sex-related differences in prevalence, clinical presentation, and outcome of cardiac channelopathies are increasingly recognized, despite their autosomal transmission and hence equal genetic predisposition among sexes. In congenital long-QT syndrome, adult women carry a greater risk for Torsades de pointes and sudden cardiac death than do men. In contrast, Brugada syndrome is observed predominantly in adult men, with a considerably higher risk of arrhythmic sudden cardiac death in adult men than in women. In both conditions, the risk for arrhythmias varies with age. Sex-associated differences appear less evident in other cardiac channelopathies, likely a reflection of their rare(r) occurrence and our limited knowledge. In several cardiac channelopathies, sex-specific predictors of outcome have been identified. Together with genetic and environmental factors, sex hormones contribute to the sex-related disparities in cardiac channelopathies through modulation of the expression and function of cardiac ion channels. Despite these insights, essential knowledge gaps exist in the mechanistic understanding of these differences, warranting further investigation. Precise application of the available knowledge may improve the individualized care of patients with cardiac channelopathies. Promoting the reporting of sex-related phenotype and outcome parameters in clinical and experimental studies and advancing research on cardiac channelopathy animal models should translate into improved patient outcomes. This review provides a critical digest of the current evidence for sex-related differences in cardiac channelopathies and emphasizes their clinical implications and remaining gaps requiring further research.

BACKGROUND The implantation of left ventricular (LV) leads for cardiac resynchronization therapy (CRT) and the management of lead-related complications can be challenging. The introduction of the quadripolar IS-4 LV lead may have facilitated the implantation procedure and may have reduced lead-related complications. Data of long-term follow-up (FU) comparing the IS-4 lead with the IS-1 LV lead are rare and conflicting. PURPOSE Comparison of lead-related complications and all-cause mortality between CRT patients who received an IS-4 or an IS-1 LV lead in the long-term FU. METHODS Adults with an indication for a CRT-Defibrillator or CRT-Pacemaker, a successful endovascular IS-4 or IS-1 LV lead implantation, and a minimal FU of three years were included in this retrospective study. The combined primary endpoint was freedom from lead-related complications defined as (i) occurrence of persisting high pacing threshold (>2.75V/0.4ms), (ii) unresolved phrenic nerve stimulation, (iii) LV lead dislodgement/disruption, (iv) the necessity of re-interventions affecting the LV lead, and (v) LV lead deactivation/explantation. Secondary endpoints were all singular complications and all-cause mortality. RESULTS Eligible for the study were 133 patients (IS-4 n = 66; IS-1 n = 67) with a mean FU of 4.03 ± 1.93 years. Baseline characteristics of both patient groups did not differ significantly. Freedom from lead-related complications was higher in patients with an IS-4 lead as compared to an IS-1 lead (Figure 1; 87.9% vs. 65.7%; p = 0.002). The secondary outcomes showed a higher rate of LV lead dislodgement/disruption (4.5% vs. 17.9%; p = 0.015) in the IS-1 patient group and more patients suffered from unresolved phrenic nerve stimulation with an IS-1 lead (3.0% vs. 13.4%; p = 0.029). LV lead deactivation/explantation during FU and LV lead-related re-interventions were fewer in case of an IS-4 lead (4.5% vs 22.4%; p = 0.003; 6.1% vs. 17.9%; p = 0.036, respectively). The rate of persisting high pacing thresholds and all-cause mortality did not differ (4.5% vs. 9.0%; p = 0.492; 22.7% vs 25.4%; p = 0.721, respectively). CONCLUSION The quadripolar IS-4 LV lead showed in this retrospective study a better long-term performance than the bipolar IS-1 lead. Abstract Figure 1

Background Structural disarray of hypertrophied myocytes and interstitial fibrosis characterize hypertrophic cardiomyopathy (HCM). These morphological changes also affect atrial myocytes and, together with hemodynamic alterations because of HCM, may lead to atrial cardiomyopathy. Purpose To investigate the incremental value of P-wave parameters to differentiate left ventricular hypertrophy (LVH) because of HCM from LVH in hypertensive heart disease (HHD) and athletes heart. Methods In a prospective study, we compared electrocardiographic (including signal-averaged ECG of the P wave) and echocardiographic data of patients with HCM, HHD and athletes heart. We developed a predictive model with a simple scoring system to identify HCM. Results We compared data of 27 patients with HCM (70% males, 49.8 ± 14.5 years), 324 patients with HHD (52% males, 74.8 ± 5.5 years), and 215 subjects with athletes heart (72% males, 42.3 ± 7.5). The table shows the significant differences among the 3 groups. We included the following parameters into a predictive score to differentiate HCM from other forms of LVH: QRS width (>88ms = 1 point), P-wave integral (>688µVs = 1 point) and septum thickness (>12mm = 2 points). A score >2 (Youden index 0.626) correctly classified HCM in 81% of the cases with a sensitivity and specificity of 82% an 81%, respectively. Conclusion Differentiation of HCM from other forms of LVH is improved by including atrial parameters. A simple scoring system including septum thickness, QRS width and P wave integral allowed identification of patients with HCM with a sensitivity and specificity of >80%. This score needs to be validated prospectively. Table 1 HCM HHD Athletes P-value HCM vs HHD* HCM vs Athletes* 95%-CI P-value 95%-CI P-value P-wave duration [ms] 152.7 ± 25.8 143.9 ± 16.5 133.5 ± 14.2 Abstract Figure 1

Subdermal solar harvesting has the potential to obviate the need for the periodic battery replacements as required in patients with cardiac pacemakers. The achievable power output of the subdermal solar module depends on implantation depth, optical skin properties and to an important part on solar cell characteristics. Monte Carlo simulations of light distribution in human skin were used to estimate the power output of subdermal solar cells under midday sunlight exposure in geographical mid-latitudes as a function of implantation depth and solar panel size. For the darkest skin type, the daily energy demand of a modern cardiac pacemaker (0.864 J at a power demand of 10 μ W ) can be provided by a 2 cm 2 solar cell implanted subdermally at a depth of 3 mm when exposed to just 11 min of midday, clear sky irradiance. Our study reveals that solar harvesting with relatively small solar cells if optimized for the spectral subdermal fluence has the potential to power cardiac pacemakers in all skin types within reasonable irradiation exposure times. Solar energy harvesting is very promising to power electronic implants.

Background Pacing leads are the Achilles heel of pacemakers. Most manufacturers report a 3-year survival rate of >99% of their leads. We observed several failures of the Beflex/Vega leads (MicroPort, Shanghai, China; formerly Sorin/LivaNova). Objective The purpose of this study was to investigate failure rates of Beflex/Vega leads. Methods We analyzed the performance of Beflex/Vega leads implanted at our tertiary referral center. All-cause lead failures (any issues requiring reinterventions such as lead dislocations, cardiac perforations, and electrical abnormalities) were identified during follow-up. The Beflex/Vega lead was compared with a reference lead (CapSureFix Novus 5076, Medtronic, Minneapolis, MN) implanted within the same period and by the same operators. Results A total of 585 leads were analyzed (382 Beflex/Vega and 203 CapSureFix Novus 5076 leads). Cumulative failure rate estimates were 5.2%, 6.3%, and 12.4% after 1, 2, and 3 years for the Beflex/Vega lead. This was worse compared to the reference lead (1.5%, 1.5%, 3.7% after 1, 2, and 3 years; P = .001). Early failure manifestations up to 3 months occurred at a similar rate (Beflex/Vega vs CapSureFix Novus 5076 lead: 1.3% vs 0.5% for dislocations; 1.3% vs 1.0% for perforations). During follow-up, electrical abnormalities such as noise oversensing (P = .013) and increased pacing thresholds (P = .003) became more frequent in the Beflex/Vega group. Electrical abnormalities were the most common failure manifestation 3 years after implantation in this group (9.4% vs 2.2% for the CapSureFix Novus 5076). Conclusion The failure rate of the Beflex/Vega lead of >10% after 3 years was higher than that of a competitor lead. This gives rise to concern since >135,000 such leads are active worldwide.

Visual Abstract, Highlights • The new leadless pacemakers overcome important limitations of conventional devices but only provide single-chamber pacing capability. • The presented concept involves 2 leadless pacemakers that communicate wirelessly with each other and thus enable synchronized leadless dual-chamber pacing. • A novel technology is presented for pacemaker communication, using the myocardium and blood as the transmission medium. Optimal communication parameters were assessed in vivo and in vitro, and various features having an influence on signal transmission have been identified. • A leadless dual-chamber pacemaker prototype was developed and successfully tested in vivo. • The presented technique has shown to be a promising and energy-efficient wireless communication method for leadless dual-chamber pacemakers., Summary Contemporary leadless pacemakers only feature single-chamber pacing capability. This study presents a prototype of a leadless dual-chamber pacemaker. Highly energy-efficient intrabody communication was implemented for wireless pacemaker synchronization. Optimal communication parameters were obtained by in vivo and ex vivo measurements in the heart and blood. The prototype successfully performed dual-chamber pacing in vivo. The presented wireless communication method may in the future also enable leadless cardiac resynchronization therapy.

OBJECTIVE Unexplained cardiac arrest (UCA) is often the first manifestation of an inherited arrhythmogenic disease. Genetic testing in UCA is challenging due to the complexities of variant interpretation in the absence of supporting cardiac phenotype. We aimed to investigate if a KCNQ1 variant [p.(Pro64_Pro70del)], previously reported as pathogenic, contributes to the long-QT syndrome phenotype, co-segregates with disease or affects KCNQ1 function in vitro. METHODS DNA was extracted from peripheral blood of a 22-year-old male after resuscitation from UCA. Targeted exome sequencing was performed using the TruSight-One Sequencing Panel (Illumina). Variants in 190 clinically relevant cardiac genes with minor allele frequency A in PKP2 (p.Arg811Ser), classified as likely benign. Two asymptomatic family members with no evident phenotype hosted the KCNQ1 variant. Functional studies showed that the wild-type and mutant channels have no significant differences in current levels, conductance-voltage relationships, as well as activation and deactivation kinetics, in the absence and presence of the auxiliary subunit KCNE1. CONCLUSIONS Based on our data and previous reports, available evidence is insufficient to consider the variant KCNQ1:c.190_210del as pathogenic. Our findings call for cautious interpretation of genetic tests in UCA in the absence of a clinical phenotype.

Introduction Pacing leads remain the weak link of current pacemaker systems. Various differences in design and material exist among companies. Lead performance is mainly assessed via post-marketing studies of the manufacturing companies. Reliable independent reports are rare. We aimed to study the early and long-term performance of the Microport (formerly Sorin/Livanova) Beflex and Vega leads at our centre, for which a lead survival >99% at 3 years has been reported by the company. Method In this single centre, retrospective study we analysed the performance of all right ventricular Microport pacemaker leads implanted at our centre between January 2014 and January 2018. Only first pacemaker implants were considered. Lead failure was defined as any lead issue requiring reintervention during follow-up (dislocation, perforation, electrical abnormalities such as lead noise or excessively high thresholds). Results A total of 271 Microport right ventricular pacing leads were implanted (233 Beflex and 38 Vega leads). Mean patient age was 76±13.1 years (66% men). Dual chamber pacemakers were implanted in 162 patients (60%) and single chamber in 109 (40%). Mean threshold at implant was 0.6V/0.5ms (range 0.3–1.2V), mean R wave 13.2 mV (range 1.5–30mV) and mean impedance 816 Ohm (range 469–1639 Ohm). Patients without available follow-up information were excluded (N=18, 6.6%). The remaining 253 patients (93.4%) were analysed. Median follow-up was 1.26 years, IQR [25%=0.91 and 75%=2.24]. We observed a total of 25 lead failures (10%). Lead dislocation occurred in 2 cases (0.8%), lead perforation in 5 cases (2%), electrical abnormalities in 6 cases (2.4%) and excessively high threshold in 12 cases (4.8%; mean voltage 4V, range 2–7.5V; mean pulse width 0.75ms, range 0.35–1ms). Yearly incidence of lead failure per 100 leads was 6.1% (95%-CI [4.09–8.98] with a failure rate of 12.74% at 3 year in Kaplan-Meier analysis (Figure). Figure 1 Conclusion We found an unexpectedly high rate of lead failure of the Microport Beflex and Vega pacing leads at our centre. The two main reasons for premature lead failure were excessively high thresholds as well as electrical abnormalities during follow-up. Comparison of lead performance with other centres and against other leads are needed to further assess the magnitude of the problem.

Introduction Patients with complete transposition of the great arteries (d-TGA) and atrial switch face a high lifetime risk of arrhythmias. Interventions in these patients are challenging because of their particular anatomy. Reports on ablation procedures in this patient population are scarce and missing for Switzerland. Method We retrospectively analyzed all ablation procedures performed in the above-mentioned population at a Swiss tertiary care center. Results Among 73 d-TGA pts. (71% male; N=37 Senning; N=36 Mustard) followed at our center, 17 ablations were performed in 11 pts. (15%; one ablation in 8 pts., two in 2 pts. and five in 1 patient). Median age at first ablation was 34 years (range 15–49 years). A total of 17 different intra-atrial reentry tachycardias (IART) and 3 AVNRT were targeted. Of the IART, 10 were cavotricuspid isthmus (CTI)-dependent and 7 were not. In two procedures (12%) only the systemic venous (SV) baffle was accessed for ablation. In 15 procedures (88%), ablation was performed within the pulmonary venous (PV) baffle. Access to the PV baffle was retrograde via the aorta in 6 cases (35%), via a baffle leak in 3 (18%) and via baffle puncture in 6 (35%). All procedures with retrograde approach to the PV baffle or with SV baffle only ablation were performed up to January 2012 and all remaining procedures afterwards. The 3 pts. requiring repeat procedures had retrograde or SV baffle approaches initially, and one additional ablation via baffle puncture was successful. The CTI was targeted in 10 pts. (91%) and ablation was finally successful in all with bidirectional block demonstrated in 8 pts. The coronary sinus was found to drain into the SV baffle in 5 pts. (46%) and useful for assessment of CTI block. The seven CTI-independent IART were scar-related micro-reentries. Ablation of all 3 AVNRTs was successful after one procedure without recurrence. Slow pathway ablation was performed in the SV baffle in two and in the PV baffle in one case (Figure). After a median follow-up of 7 months (range 2–186 months) 9 pts. are without recurrence and in 2 pts. rare self-limited arrhythmias still occur. No procedural complications occurred. Conclusion Arrhythmias in patients with complete d-TGA and atrial switch are mainly CTI-dependent IART or scar-related micro-reentries, and a few patients also have AVNRT. Ablation of these arrhythmias is safe and successful if PV baffle access is achieved via a baffle leak or baffle puncture.

BACKGROUND Radiofrequency catheter ablation (RFA) is an effective treatment for atrial fibrillation. However, ablation lesions are usually only assessed functionally. The immediate effect of RFA on the tissue is not directly visualized. Optical coherence tomography (OCT) is an imaging technique that uses light to capture high-resolution images with histology-like quality. Therefore, it might be used for high-precision imaging of ablation lesions. METHODS AND RESULTS Radiofrequency ablation lesions (n = 25) were produced on the freshly excised left and right ventricular porcine endocardium. A Thermocool ST SF NAV ablation catheter (Biosense Webster Inc) and an EP-Shuttle ablation generator (Stockert GmbH) were used to produce ablation lesions with powers from 10 to 40 W (energies ranging from 100 Ws to 900 Ws). After ablation, the tissue was imaged with a swept source OCT system (at a wavelength of 1300 nm). Subsequently, the ablation lesions underwent the histological analysis. The ablation lesions could be visualized by OCT in all 17 samples with ablation powers ≥20 W, meanwhile, no lesion could be observed in the other eight samples with lower power (10 W). Lesion depths and lesion radiuses, as assessed by OCT, correlated well with those observed on the subsequent histological analysis (Spearman's r = 0.94, P

AIMS Supraventricular arrhythmia diagnosis using the surface electrocardiogram (sECG) is often cumbersome due to limited atrial signal quality. In some instances, use of esophageal electrocardiography (eECG) may facilitate the diagnosis. Here, we present a novel approach to reconstruct cardiac activation maps from eECG recordings. METHODS eECGs and sECGs were recorded from 19 individuals using standard acquisition tools. From the recordings, algorithms were developed to estimate the esophageal ECG catheter's position and to reconstruct high-resolution mappings of the cardiac electric activity projected in the esophagus over time. RESULTS Esophageal two-dimensional activation maps were created for five healthy individuals and 14 patients suffering from different arrhythmias. The maps are displayed as time-dependent contour plots, which not only show voltage over time as conventional ECGs, but also the location, direction, and projected propagation speed of the cardiac depolarization wavefront in the esophagus. Representative examples of sinus rhythm, atrial flutter, and ventricular pre-excitation are shown. CONCLUSION The methodology presented in this report provides a high-resolution view of the cardiac electric field in the esophagus. It is the first step toward a three-dimensional mapping system, which shall be able to reconstruct a three-dimensional view of the cardiac activation from recordings within the esophagus.

In 2018, the Swiss Society of Cardiology celebrated its70thyear. Is this also a celebration for the achievement ofwomen in cardiology? Yes and no.

PURPOSE To compare lead failure manifestation and lead performance of the Biotronik Linox/Sorin Vigila defibrillator lead (Linox group) with the St. Jude Medical Riata/Riata ST (Riata group) and Medtronic Sprint Fidelis defibrillator leads (Fidelis group). METHODS We assessed the performance of all aforementioned leads implanted at our center and investigated the manifestation of lead failures. RESULTS Of 93 Linox, 86 Riata, and 81 Fidelis leads implanted at our center, 11 (12%), 22 (26%), and 25 (31%) leads failed during a median follow-up of 46, 61, and 84 months, respectively. Inappropriate shocks were delivered in 64% (Linox), 5% (Riata), and 32% (Fidelis) of lead failures; a device alert was noted in none (Linox), 5% (Riata), and 52% (Fidelis); and lead failure was a coincidental finding in 36% (Linox), 91% (Riata), and 16% (Fidelis) of cases (p

OBJECTIVE Abnormal ECG findings suggestive of cardiac disease are frequent in patients with funnel chest, although structural heart disease is rare. Electrocardiographic characteristics and changes following new surgical treatments in young adults are not described so far. The aim of the study was to analyze electrocardiographic characteristics of patients with funnel chest before and after minimally invasive funnel chest correction by the Nuss procedure. METHODS Twenty-six patients with surgical correction of funnel chest using pectus bar were included. Twelve-lead ECGs before and later than one year after surgery were analyzed. RESULTS In postoperative ECGs, amplitude of P wave in lead II and negative terminal amplitude of P wave in lead V1 decreased from 0.13 to 0.10mV (p=0.03), and from 0.10 to 0.04mV (p

Genetic testing in survivors of sudden cardiac arrest (SCA) with a suspicious cardiac phenotype is considered clinically useful, whereas its value in the absence of phenotype is disputed. We aimed to evaluate the clinical utility of genetic testing in survivors of SCA with or without cardiac phenotype. Sixty unrelated SCA survivors (median age: 34 [interquartile range 20 to 43] years, 82% male) without coronary artery disease were included: 24 (40%) with detectable cardiac phenotype (Ph(+)SCA) after the SCA event and 36 (60%) with no clear cardiac phenotype (Ph(-)SCA). The targeted exome sequencing was performed using the TruSight-One Sequencing Panel (Illumina). Variants in 185 clinically relevant cardiac genes with minor allele frequency

Objective: A new generation of leadless cardiac pacemakers effectively overcomes the main limitations of conventional devices, but only offer single-chamber pacing, although dual-chamber or multisite pacing is highly desirable for most patients. The combination of several leadless pacemakers could facilitate a leadless multisite pacemaker but requires an energy-efficient wireless communication for device synchronization. This study investigates the characteristics of conductive intracardiac communication between leadless pacemakers to provide a basis for future designs of leadless multisite pacemaker systems. Methods: Signal propagation and impedance behavior of blood and heart tissue were examined by in vitro and in vivo measurements on domestic pig hearts and by finite-element simulations in the frequency range of 1 kHz to 1 MHz. Results: A better signal transmission was obtained for frequencies higher than 10 kHz. The influence of a variety of practical parameters on signal transmission could be identified. A larger distance between pacemakers increases signal attenuation. A better signal transmission is obtained through larger inter-electrode distances and a larger electrode surface area. Furthermore, the influence of pacemaker encapsulation and relative device orientation was assessed. Conclusion: This study suggests that conductive intracardiac communication is well suited to be incorporated in leadless pacemakers. It potentially offers very low power consumption using low communication frequencies. Significance: The presented technique enables highly desired leadless multisite pacing in near future.