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Background: Stereotactic arrhythmia radioablation (STAR) is delivered with a planning target volume (PTV) prescription dose of 25 Gy, mostly to the surrounding 75–85% isodose line. This means that the average and maximum dose received by the target is less than 35 Gy, which is the minimum threshold required to create a homogenous transmural fibrosis. Similar to catheter ablation, the primary objective of STAR should be transmural fibrosis to prevent heterogenous intracardiac conduction velocities and the occurrence of sustained ventricular arrhythmias (sVA) caused by reentry. We hypothesize that the current dose prescription used in STAR is inadequate for the long-term prevention of sVA and that a significant increase in dose is necessary to induce transmural scar formation. Objective: A single arm, multi-center, phase II, dose escalation prospective clinical trial employing the i3 + 3 design is being conducted to examine the safety of a radiation dose-escalation strategy aimed at inducing transmural scar formation. The ultimate objective of this trial is to decrease the likelihood of sVA recurrence in patients at risk. Methods: Patients with ischemic or non-ischemic cardiomyopathy and recurrent sVA, with an ICD and history of ≥ 1 catheter ablation for sVA will be included. This is a prospective, multicenter, one-arm, dose-escalation trial utilizing the i3 + 3 design, a modified 3 + 3 specifically created to overcome limitations in traditional dose-finding studies. A total of 15 patients will be recruited. The trial aims to escalate the ITV dose from 27.0 Gy to an ITV prescription dose-equivalent level of maximum 35.1 Gy by keeping the PTV prescription dose constant at 25 Gy while increasing the dose to the target (i.e. the VT substrate without PTV margin) by step-wise reduction of the prescribing isodose line (85% down to 65%). The primary outcome of this trial is safety measured by registered radiation associated adverse events (AE) up to 90 days after study intervention including radiation associated serious adverse events graded as at least 4 or 5 according to CTCAE v5, radiation pneumonitis or pericarditis requiring hospitalization and decrease in LVEF ≥ 10% as assessed by echocardiography or cardiac MRI at 90 days after STAR. The sample size was determined assuming an acceptable primary outcome event rate of 20%. Secondary outcomes include sVA burden at 6 months after STAR, time to first sVA recurrence, reduction in appropriate ICD therapies, the need for escalation of antiarrhythmic drugs, non-radiation associated safety and patient reported outcome measures such as SF-36 and EQ5D. Discussion: DEFT-STAR is an innovative prospective phase II trial that aims to evaluate the optimal radiation dose for STAR in patients with therapy-refractory sVA. The trial has obtained IRB approval and focuses on determining the safe and effective radiation dose to be employed in the STAR procedure. Trial registration: NCT05594368. [ABSTRACT FROM AUTHOR]

Background: Prediction of the chamber of origin in patients with outflow tract ventricular arrhythmias (OTVA) remains challenging. A clinical risk score based on age, sex and presence of hypertension was associated with a left ventricular outflow tract (LVOT) origin. We aimed to validate this clinical score to predict an LVOT origin in patients with OTVA. Methods: In a two‐center observational cohort study, unselected patients undergoing catheter ablation (CA) for OTVA were enrolled. All procedures were performed using an electroanatomical mapping system. Successful ablation was defined as a ≥80% reduction of the initial overall PVC burden after 3 months of follow‐up. Patients with unsuccessful ablation were excluded from this analysis. Results: We included 187 consecutive patients with successful CA of idiopathic OTVA. Mean age was 52 ± 15 years, 102 patients (55%) were female, and 74 (40%) suffered from hypertension. A LVOT origin was found in 64 patients (34%). A score incorporating age, sex and presence of hypertension reached 73% sensitivity and 67% specificity for a low (0–1) and high (2–3) score, to predict an LVOT origin. The combination of one ECG algorithm (V2S/V3R‐index) with the clinical score resulted in a sensitivity and specificity of 81% and 70% for PVCs with R/S transition at V3. Conclusion: The published clinical score yielded a lower sensitivity and specificity in our cohort. However, for PVCs with R/S transition at V3, the combination with an existing ECG algorithm can improve the predictability of LVOT origin. [ABSTRACT FROM AUTHOR]

Fragmented QRS (fQRS) is an electrocardiographic (ECG) marker of myocardial conduction abnormality, characterized by additional notches in the QRS complex. The presence of fQRS has been associated with an increased risk of all-cause mortality and arrhythmia in patients with cardiovascular disease. However, current binary visual analysis is prone to intra- and inter-observer variability and different definitions are problematic in clinical practice. Therefore, objective quantification of fQRS is needed and could further improve risk stratification of these patients. We present an automated method for fQRS detection and quantification. First, a novel robust QRS complex segmentation strategy is proposed, which combines multi-lead information and excludes abnormal heartbeats automatically. Afterwards extracted features, based on variational mode decomposition (VMD), phase-rectified signal averaging (PRSA) and the number of baseline-crossings of the ECG, were used to train a machine learning classifier (Support Vector Machine) to discriminate fragmented from non-fragmented ECG-traces using multi-center data and combining different fQRS criteria used in clinical settings. The best model was trained on the combination of two independent previously annotated datasets and, compared to these visual fQRS annotations, achieved Kappa scores of 0.68 and 0.44, respectively. We also show that the algorithm might be used in both regular sinus rhythm and irregular beats during atrial fibrillation. These results demonstrate that the proposed approach could be relevant for clinical practice by objectively assessing and quantifying fQRS. The study sets the path for further clinical application of the developed automated fQRS algorithm. [ABSTRACT FROM AUTHOR]

Background: Radiofrequency catheter ablation of idiopathic premature ventricular complexes (PVCs) is an effective method for eliminating symptoms and preventing/reversing arrhythmia‐induced cardiomyopathy. One reason for procedural failure is low PVC frequency during the procedure. We aimed to investigate the relation between pre‐procedural PVC burden and outcome of idiopathic PVC catheter ablation. Methods: Patients who underwent idiopathic PVC ablation between 2013 and 2019 at two tertiary referral centers were retrospectively included. All procedures were performed using irrigated‐tip ablation catheters and a 3D electro‐anatomical mapping system. Sustained ablation success was defined as a ≥80% reduction of pre‐procedural PVC burden determined by 24h‐Holter at follow‐up. Results: Overall, 254 patients (median age 54 years [IQR 42–64]; 47% male) were enrolled. The median pre‐ablation PVC‐burden was 22% (IQR 11–31%), which was reduced to a post‐ablation PVC burden of 0.3% (IQR 0–4%) after a median of 90 days. Sustained ablation success was achieved in 182 patients (72%). Pre‐procedural PVC burden did not differ between patients with sustained ablation success and recurrence during follow‐up (median 21% vs. 22%, p =.76). When assessed in pre‐ablation PVC‐burden groups of ≤5%, 6–15%, 16–30%, and ≥31%, sustained ablation success was achieved in 67%, 75%, 71%, and 72%, respectively, with no significant difference (p =.89). Sustained ablation outcome for PVC‐burden ≤5% versus >5% showed no difference either (67% vs. 72%, p =.52). Conclusions: Pre‐procedural Holter‐determined PVC burden does not predict the outcome of idiopathic PVC ablation. Thus, catheter ablation may be a reasonable first choice also for patients with symptomatic yet rare PVCs. [ABSTRACT FROM AUTHOR]

Background: Patients with atrial fibrillation (AF) have an increased risk for the development of heart failure (HF). In this study, we aimed to detect predictors of HF hospitalizations in an unselected AF population. Methods: The Basel Atrial Fibrillation Cohort Study is an ongoing observational multicenter cohort study in Switzerland. For this analysis, 1193 patients with documented AF underwent clinical examination, venous blood sampling and resting 12-lead ECG at baseline. Questionnaires about lifestyle and medical history were obtained in person at baseline and during yearly follow-up phone calls. HF hospitalizations were validated by two independent physicians. Cox regression analyses were performed using a forward selection strategy. Results: Overall, 29.8% of all patients were female and mean age was 69 ±12 years. Mean follow-up time was 3.7 ±1.5 years. Hospitalization for HF occurred in 110 patients, corresponding to an incidence of 2.5 events per 100 person years of follow-up. Independent predictors for HF were body mass index (HR 1.40 [95%CI 1.17; 1.66], p = 0.0002), chronic kidney disease (2.27 [1.49; 3.45], p = 0.0001), diabetes mellitus (2.13 [1.41; 3.24], p = 0.0004), QTc interval (1.25 [1.04; 1.49], p = 0.02), brain natriuretic peptide (2.19 [1.73; 2.77], p<0.0001), diastolic blood pressure (0.79 [0.65; 0.96], p = 0.02), history of pulmonary vein isolation or electrical cardioversion (0.54 [0.36; 0.80], p = 0.003) and serum chloride (0.82 [0.70; 0.96], p = 0.02). Conclusions: In this unselected AF population, several traditional cardiovascular risk factors and arrhythmia interventions predicted HF hospitalizations, providing potential opportunities for the implementation of strategies to reduce HF among AF patients. [ABSTRACT FROM AUTHOR]

Echocardiography to Predict AF Recurrence Background Arrhythmia recurrence after atrial fibrillation (AF) ablation remains high and requires repeat interventions in a substantial number of patients. We assessed the value of conventional and 3-D echocardiography to predict AF recurrence. Methods and Results Consecutive patients undergoing AF ablation by means of pulmonary vein isolation were included in a prospective registry. Echocardiograms were obtained prior to the ablation procedure, and analyzed offline in a standardized manner, including 3-D left atrial (LA) volumetry and determination of LA function and sphericity. The primary endpoint, AF recurrence (>30 seconds) between 3 to 12 months after AF ablation, was independently adjudicated. We included 276 patients (73% male, mean age 59.9 ± 9.9 years). Paroxysmal and persistent AF were present in 178 (64%) and 98 (36%) patients, respectively. Mean left ventricular ejection fraction and indexed LA volume in 3-D (LAVI) were 52 ± 12% and 42 ± 13 mL/m2, respectively. AF recurrence was observed in 110 (40%) patients after a single procedure. Median (interquartile range) time to AF recurrence was 123 (92; 236) days. In multivariable Cox regression models, the only predictors for AF recurrence were the minimal, maximal, and indexed 3-D LA volumes, P = 0.024, P = 0.016, and P = 0.014, respectively. Quartile specific analysis of 3-D LAVI showed an HR of 1.885 (95%CI 1.066-3.334; P for trend = 0.015) for the highest compared to the lowest quartile. Conclusion Our results show the important role of LA volume for the long-term freedom from arrhythmia after AF ablation. These data also highlight the potential of 3-D echocardiography in this context and may facilitate patient selection for AF ablation. [ABSTRACT FROM AUTHOR]

Introduction: Left atrial (LA) enlargement is an important risk factor for incident stroke and a key determinant for the success of rhythm control strategies in patients with atrial fibrillation (AF). However, factors associated with LA volume in AF patients remain poorly understood. Methods: Patients with paroxysmal or persistent AF were enrolled in this study. Real time 3-D echocardiography was performed in all participants and analyzed offline in a standardized manner. We performed stepwise backward linear regression analyses using a broad set of clinical parameters to determine independent correlates for 3-D LA volume. Results: We included 210 patients (70.9% male, mean age 61±11years). Paroxysmal and persistent AF were present in 95 (45%) and 115 (55%) patients, respectively. Overall, 115 (55%) had hypertension, 11 (5%) had diabetes, and 18 (9%) had ischemic heart disease. Mean indexed LA volume was 36±12ml/m2. In multivariable models, significant associations were found for female sex (β coefficient -10.51 (95% confidence interval (CI) -17.85;-3.16), p = 0.0053), undergoing cardioversion (β 11.95 (CI 5.15; 18.74), p = 0.0006), diabetes (β 14.23 (CI 2.36; 26.10), p = 0.019), body surface area (BSA) (β 34.21 (CI 19.30; 49.12), p<0.0001), glomerular filtration rate (β -0.21 (CI -0.36; -0.06), p = 0.0064) and plasma levels of NT-pro brain natriuretic peptide (NT-proBNP) (β 6.79 (CI 4.05; 9.52), p<0.0001), but not age (p = 0.59) or hypertension (p = 0.42). Our final model explained 52% of the LA volume variability. Conclusions: In patients with AF, the most important correlates with LA volume are sex, BSA, diabetes, renal function and NT-proBNP, but not age or hypertension. These results may help to refine rhythm control strategies in AF patients. [ABSTRACT FROM AUTHOR]

Imaging of the heart anatomy plays an important role, especially in catheter ablation for the treatment of arrhythmias in adults with congenital heart disease (ACHD). We present a comprehensive overview of the current state‐of‐the‐art modalities available to plan and guide catheter ablation in an ACHD patient. In addition to the clinical assessment of the computed tomography and the integration of 3D reconstructions into the electroanatomical mapping system, 3D printing and virtual reality assessment showed its value in preprocedural planning of the intervention. [ABSTRACT FROM AUTHOR]

Abstract: A case of a professional ice-hockey with a blunt chest trauma is presented. A year after the first cardiac evaluation, he experienced sustained ventricular tachycardia after another slight chest trauma. An implantable cardioverter-defibrillator was implanted. The pathophysiological background of tachycardias after a blunt chest trauma and its management are discussed. [Copyright &y& Elsevier]

Introduction: The advent of electroanatomical mapping (EAM) systems for pulmonary vein isolation (PVI) has dramatically decreased radiation exposure. However, the need for some fluoroscopy remains for obtaining left atrial (LA) access. The aim was to test the feasibility of fluoroscopy-free PVI in patients with atrial fibrillation (AF) and a patent foramen ovale (PFO) guided solely by an EAM system. Methods: Consecutive patients with AF undergoing PVI and documented PFO were studied. An EAM-guided approach without fluoroscopy and ultrasound was used. After completing the map of the right atrium, the superior vena cava and the coronary sinus, a catheter pull-down to the PFO was performed allowing LA access. The map of the LA and subsequent PVI was also performed without fluoroscopy. Results: 30 patients [age 61±12 years, 73% male, ejection fraction 0.64 (0.53–0.65), LA size in parasternal long axis 38±7 mm] undergoing PVI were included. The time required for right atrial mapping including transseptal crossing was 9±4 minutes. Total procedure time was 127±37 minutes. Fluoroscopy-free PVI was feasible in 26/30 (87%) patients. In four patients, fluoroscopy was needed to access (n = 3) or to re-access (n = 1) the LA. In these four patients, total fluoroscopy time was 5±3 min and the DAP was 14.9±13.4 Gy*cm2. Single-procedure success rate was 80% (24/30) after a median follow-up of 12 months. Conclusion: In patients with a documented PFO, completely fluoroscopy-free PVI is feasible in the vast majority of cases. [ABSTRACT FROM AUTHOR]

Background To categorize indications of permanent pacemaker (PPM) implantation after transcatheter aortic valve implantation (TAVI), to determine predictors for conduction disturbances and to quantify the need for ventricular pacing during follow-up. Method We studied 97 patients (median age 83 years, 58% female) undergoing TAVI using the Medtronic CoreValve Revalving System (MCRS; Medtronic Inc., Minneapolis, MN, USA) or Edwards-Sapien Valve (Edwards Lifesciences, Irvine, CA, USA). During follow-up, no need for ventricular pacing was defined as <1% ventricular pacing and intrinsic 1:1 atrioventricular (AV) conduction. Results In the 35 patients (36.1%) undergoing PPM implantation three indication categories were identified: (1) high-grade AV block (Mobitz 2 or higher), (2) new-onset left bundle branch block (LBBB) with a prolonged PR interval, and (3) new-onset LBBB. The only independent predictors of high-grade AV block were the use of MCRS (odds ratio [OR] 79.25; 95% confidence interval [CI] 4.57-1373.31) and the presence of preprocedural right bundle branch block (OR 81.95; 95% 95% CI 8.72-770.46). Whereas high-grade AV block resolved only in 17% of cases, none of the patients receiving a PPM due to LBBB with or without PR prolongation required ventricular pacing during follow-up. Conclusion Our findings justify early PPM implantation in patients with high-grade AV block and may suggest a more conservative approach to PPM implantation in patients with new-onset LBBB after TAVI. [ABSTRACT FROM AUTHOR]

Aims The aim of this study was to determine the relationship between improved ejection fraction (EF) and occurrence of arrhythmias in patients with cardiac resynchronization therapy devices with defibrillator function (CRT-D). The hypothesis was that patients who experienced a marked improvement in EF also had fewer appropriate defibrillator interventions. Methods and results We analysed data of 270 patients from2 prospective registries with follow-up of ≥12 months and echocardiography performed ≥8 months after CRT-D implantation. The discriminator was whether left ventricular ejection fraction (LVEF) improved to >35% [cut-off for primary prevention implantable cardioverter-defibrillator (ICD) implantation]. Mean age was 61 ± 11 years, LVEF 22 ± 5%, and follow-up 40 ± 22 months. Ischaemic cardiomyopathy was present in 48%, and secondary prevention indication was present in 25%. Implantable cardioverter-defibrillator interventions were delivered to 35% of patients. Echocardiography (20 ± 15 months after implantation) showed an improvement in LVEF from 22% (SD 5.4%) to 30% (SD 9.8%). Improvement to >35% was seen in 21% of patients. Those who improved to >35% had fewer ICD interventions than those who did not (23 vs.38%; P-value 0.03). Analysing only patients with a primary prevention indication and stratifying again in patients with and without improvement of LVEF to >35%, the latter had highly significant more ICD-therapies (6 vs. 31%; P-value 0.0008). Conclusion Patients with CRT-D for primary prevention, whose LVEF improved to >35% during mid-term follow-up, are at low risk of first ICD therapies beyond year 1. If similar findings are reported in other patient cohorts, this might impact on decision-making at the time of battery depletion. [ABSTRACT FROM AUTHOR]

Background: The wearable cardioverter defibrillator (WCD) uses surface electrodes to detect arrhythmia before initiating a treatment sequence. However, it is also prone to inappropriate detection due to artefacts. Objective: The aim of this study is to assess the alarm burden in patients and its impact on clinical outcomes. Methods: Patients from the nationwide Swiss WCD Registry were included. Clinical characteristics and data were obtained from the WCDs. Arrhythmia recordings ≥30 s in length were analysed and categorized as VT/VF, atrial fibrillation (AF), supraventricular tachycardia (SVT) or artefact. Results: A total of 10653 device alarms were documented in 324 of 456 patients (71.1%) over a mean WCD wear-time of 2.0 ± 1.6 months. Episode duration was 30 s or more in 2996 alarms (28.2%). One hundred and eleven (3.7%) were VT/VF episodes. The remaining recordings were inappropriate detections (2736 (91%) due to artefacts; 117 (3.7%) AF; 48 (1.6%) SVT). Two-hundred and seven patients (45%) had three or more alarms per month. Obesity was significantly associated with three or more alarms per month (p = 0.01, 27.7% vs. 15.9%). High alarm burden was not associated with a lower average daily wear time (20.8 h vs. 20.7 h, p = 0.785) or a decreased implantable cardioverter defibrillator implantation rate after stopping WCD use (48% vs. 47.3%, p = 0.156). Conclusions: In patients using WCDs, alarms emitted by the device and impending inappropriate shocks were frequent and most commonly caused by artefacts. A high alarm burden was associated with obesity but did not lead to a decreased adherence. [ABSTRACT FROM AUTHOR]

Introduction: Previous data have shown that about 25% of pts receiving CRT have atrial fibrillation (AF) but AF pts have been underrepresented in randomized CRT trials. The ESC/EHRA CRT Survey II collected data on current CRT implantation practice in 42 European countries. This analysis focuses on CRT implantation practice with regard to the presence of AF. Methods and Results: Between October 2015 and January 2017, 11.088 patients (pts) with an initial implant or upgrade from a previous device were included in the Survey. We analyzed 10843 pts with available data on AF presence. Overall, 4582 pts (42.2%) had AF. Permanent AF was present in 1889 pts. (42.4% of all AF pts), persistent AF in 994 (22.3%) and paroxysmal AF in 1548 pts (34.7%). AF pts. were older, had more advanced HF stage and more co-morbidities than pts. without AF (see table). There were also differences with regard to pacemaker dependency, CRT indication and device type implanted. Perioperative bleeding occurred slightly more often in AF pts. (1.3 vs. 0.8%, p=0.002) but the overall complication rate was not increased (5.2 vs. 5.8%, p=n.s.). Adverse events until discharge were more frequent in AF pts (5.4 vs. 4.3%, p=0.01), mostly due to increases in infections, worsening renal function and arrhythmias, but did not more often necessitate re-intervention (4.0 vs. 4.1%). Conclusion: The percentage of pts currently receiving CRT with concomitant AF is higher than previously reported. AF pts are older and sicker than pts receiving CRT without AF. Assuming a worse prognosis in the AF population, there is need for more prospective data on these pts. [ABSTRACT FROM AUTHOR]