Electrical storm treatment by percutaneous stellate ganglion block: the STAR study.

BACKGROUND AND AIMS: An electrical storm (ES) is a clinical emergency with a paucity of established treatment options. Despite initial encouraging reports about the safety and effectiveness of percutaneous stellate ganglion block (PSGB), many questions remained unsettled and evidence from a prospective multicentre study was still lacking. For these purposes, the STAR study was designed. METHODS: This is a multicentre observational study enrolling patients suffering from an ES refractory to standard treatment from 1 July 2017 to 30 June 2023. The primary outcome was the reduction of treated arrhythmic events by at least 50% comparing the 12 h following PSGB with the 12 h before the procedure. STAR operators were specifically trained to both the anterior anatomical and the lateral ultrasound-guided approach. RESULTS: A total of 131 patients from 19 centres were enrolled and underwent 184 PSGBs. Patients were mainly male (83.2%) with a median age of 68 (63.8-69.2) years and a depressed left ventricular ejection fraction (25.0 ± 12.3%). The primary outcome was reached in 92% of patients, and the median reduction of arrhythmic episodes between 12 h before and after PSGB was 100% (interquartile range -100% to -92.3%). Arrhythmic episodes requiring treatment were significantly reduced comparing 12 h before the first PSGB with 12 h after the last procedure [six (3-15.8) vs. 0 (0-1), P < .0001] and comparing 1 h before with 1 h after each procedure [2 (0-6) vs. 0 (0-0), P < .001]. One major complication occurred (0.5%). CONCLUSIONS: The findings of this large, prospective, multicentre study provide evidence in favour of the effectiveness and safety of PSGB for the treatment of refractory ES.

Pilot study to assess the early cardiac safety of carbon ion radiotherapy for intra- and para-cardiac tumours.

PURPOSE: Modern photon radiotherapy effectively spares cardiac structures more than previous volumetric approaches. Still, it is related to non-negligible cardiac toxicity due to the low-dose bath of surrounding normal tissues. However, the dosimetric advantages of particle radiotherapy make it a promising treatment for para- and intra-cardiac tumours. In the current short report, we evaluate the cardiac safety profile of carbon ion radiotherapy (CIRT) for radioresistant intra- and para-cardiac malignancies in a real-world setting. METHODS: We retrospectively analysed serum biomarkers (TnI, CRP and NT-proBNP), echocardiographic, and both 12-lead and 24-hour Holter electrocardiogram (ECG) data of consecutive patients with radioresistant intra- and para-cardiac tumours irradiated with CIRT between June 2019 and September 2022. In the CIRT planning optimization process, to minimize the delivered doses, we contoured and gave a high priority to the cardiac substructures. Weekly re-evaluative 4D computed tomography scans were carried out throughout the treatment. RESULTS: A total of 16 patients with intra- and para-cardiac localizations of radioresistant tumours were treated up to a total dose of 70.4 Gy relative biological effectiveness (RBE) and a mean heart dose of 2.41 Gy(RBE). We did not record any significant variation of the analysed serum biomarkers after CIRT nor significant changes of echocardiographic features, biventricular strain, or 12-lead and 24-hour Holter ECG parameters during 6 months of follow-up. CONCLUSION: Our pilot study suggests that carbon ion radiotherapy is a promising radiation technique capable of sparing off-target side effects at the cardiac level. A larger cohort, long-term follow-up and further prospective studies are needed to confirm these findings.

Continuous stellate ganglion block for ventricular arrhythmias: case series, systematic review, and differences from thoracic epidural anaesthesia.

AIMS: Percutaneous stellate ganglion block (PSGB) through single-bolus injection and thoracic epidural anaesthesia (TEA) have been proposed for the acute management of refractory ventricular arrhythmias (VAs). However, data on continuous PSGB (C-PSGB) are scant. The aim of this study is to report our dual-centre experience with C-PSGB and to perform a systematic review on C-PSGB and TEA. METHODS AND RESULTS: Consecutive patients receiving C-PSGB at two centres were enrolled. The systematic literature review follows the latest Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Our case series (26 patients, 88% male, 60 ± 16 years, all with advanced structural heart disease, left ventricular ejection fraction 23 ± 11%, 32 C-PSGBs performed, with a median duration of 3 days) shows that C-PSGB is feasible and safe and leads to complete VAs suppression in 59% and to overall clinical benefit in 94% of cases. Overall, 61 patients received 68 C-PSGBs and 22 TEA, with complete VA suppression in 63% of C-PSGBs (61% of patients). Most TEA procedures (55%) were performed on intubated patients, as opposed to 28% of C-PSGBs (P = 0.02); 63% of cases were on full anticoagulation at C-PSGB, none at TEA (P < 0.001). Ropivacaine and lidocaine were the most used drugs for C-PSGB, and the available data support a starting dose of 12 and 100 mg/h, respectively. No major complications occurred, yet TEA discontinuation rate due to side effects was higher than C-PSGB (18 vs. 1%, P = 0.01). CONCLUSION: Continuous PSGB seems feasible, safe, and effective for the acute management of refractory VAs. The antiarrhythmic effect may be accomplished with less concerns for concomitant anticoagulation compared with TEA and with a lower side-effect related discontinuation rate.

Real-world data of patients affected by advanced heart failure treated with implantable cardioverter defibrillator and left ventricular assist device: Results of a multicenter observational study.

BACKGROUND: Left ventricular assist device (L-VAD) implantation is increasingly used in patients with heart failure (HF) and most patients also have an implantable cardioverter defibrillator (ICD). Limited data are available on the incidence of ICD therapies and complications in this special setting. The aim of this study was to analyze the real-world incidence and predictors of ICD therapies, complications and interactions between ICD and L-VAD. METHODS: We conducted a multicenter retrospective observational study in patients with advanced HF implanted with ICD and a continuous-flow L-VAD, followed-up in five advanced HF centers in Northern Italy. RESULTS: A total of 234 patients (89.7% male, median age 59, 48.3% with ischemic etiology) were enrolled. After a median follow-up of 21 months, 66 patients (28.2%) experienced an appropriate ICD therapy, 22 patients (9.4%) an inappropriate ICD therapy, and 17 patients (7.3%) suffered from an interaction between ICD and L-VAD. The composite outcome of all ICD-related complications was reported in 41 patients (17.5%), and 121 (51.7%) experienced an L-VAD-related complication. At multivariable analysis, an active ventricular tachycardia (VT) zone and a prior ICD generator replacement were independent predictors of ICD therapies and of total ICD-related complications, respectively. CONCLUSIONS: Real-world patients with both L-VAD and ICD experience a high rate of ICD therapies and complications. Our findings suggest the importance of tailoring device programming in order to minimize the incidence of unnecessary ICD therapies, thus sparing the need for ICD generator replacement, a procedure associated to a high risk of complications.

Modern subcutaneous implantable defibrillator therapy in patients with cardiomyopathies and channelopathies: data from a large multicentre registry.

AIMS: Patients with cardiomyopathies and channelopathies are usually younger and have a predominantly arrhythmia-related prognosis; they have nearly normal life expectancy thanks to the protection against sudden cardiac death provided by the implantable cardioverter defibrillator (ICD). The subcutaneous ICD (S-ICD) is an effective alternative to the transvenous ICD and has evolved over the years. This study aimed to evaluate the rate of inappropriate shocks (IS), appropriate therapies, and device-related complications in patients with cardiomyopathies and channelopathies who underwent modern S-ICD implantation. METHODS AND RESULTS: We enrolled consecutive patients with cardiomyopathies and channelopathies who had undergone implantation of a modern S-ICD from January 2016 to December 2020 and who were followed up until December 2022. A total of 1338 S-ICD implantations were performed within the observation period. Of these patients, 628 had cardiomyopathies or channelopathies. The rate of IS at 12 months was 4.6% [95% confidence interval (CI): 2.8-6.9] in patients with cardiomyopathies and 1.1% (95% CI: 0.1-3.8) in patients with channelopathies (P = 0.032). No significant differences were noted over a median follow-up of 43 months [hazard ratio (HR): 0.76; 95% CI: 0.45-1.31; P = 0.351]. The rate of appropriate shocks at 12 months was 2.3% (95% CI: 1.1-4.1) in patients with cardiomyopathies and 2.1% (95% CI: 0.6-5.3) in patients with channelopathies (P = 1.0). The rate of device-related complications was 0.9% (95% CI: 0.3-2.3) and 3.2% (95% CI: 1.2-6.8), respectively (P = 0.074). No significant differences were noted over the entire follow-up. The need for pacing was low, occurring in 0.8% of patients. CONCLUSION: Modern S-ICDs may be a valuable alternative to transvenous ICDs in patients with cardiomyopathies and channelopathies. Our findings suggest that modern S-ICD therapy carries a low rate of IS. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Reduction in inappropriate therapies through device programming in subcutaneous implantable defibrillator patients: data from clinical practice.

AIMS: In subcutaneous implantable cardioverter defibrillator (S-ICD) recipients, the UNTOUCHED study demonstrated a very low inappropriate shock rate on programming a conditional zone between 200 and 250 bpm and a shock zone for arrhythmias >250 bpm. The extent to which this programming approach is adopted in clinical practice is still unknown, as is its impact on the rates of inappropriate and appropriate therapies. METHODS AND RESULTS: We assessed ICD programming on implantation and during follow-up in a cohort of 1468 consecutive S-ICD recipients in 56 Italian centres. We also measured the occurrence of inappropriate and appropriate shocks during follow-up. On implantation, the median programmed conditional zone cut-off was set to 200 bpm (IQR: 200-220) and the shock zone cut-off was 230 bpm (IQR: 210-250). During follow-up, the conditional zone cut-off rate was not significantly changed, while the shock zone cut-off was changed in 622 (42%) patients and the median value increased to 250 bpm (IQR: 230-250) (P < 0.001). UNTOUCHED-like programming of detection cut-offs was adopted in 426 (29%) patients immediately after device implantation, and in 714 (49%, P < 0.001) at the last follow-up. UNTOUCHED-like programming was independently associated with fewer inappropriate shocks (hazard ratio 0.50, 95%CI 0.25-0.98, P = 0.044), and had no impact on appropriate and ineffective shocks. CONCLUSIONS: In recent years, S-ICD implanting centres have increasingly programmed high arrhythmia detection cut-off rates, at the time of implantation in the case of new S-ICD recipients, and during follow-up in the case of pre-existing implants. This has contributed significantly to reducing the incidence of inappropriate shocks in clinical practice. Rordorf: Programming of the S-ICD. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Intermuscular technique for implantation of the subcutaneous implantable defibrillator: a propensity-matched case-control study.

AIMS: A previous randomized study demonstrated that the subcutaneous implantable cardioverter defibrillator (S-ICD) was noninferior to transvenous ICD with respect to device-related complications and inappropriate shocks. However, that was performed prior to the widespread adoption of pulse generator implantation in the intermuscular (IM) space instead of the traditional subcutaneous (SC) pocket. The aim of this analysis was to compare survival from device-related complications and inappropriate shocks between patients who underwent S-ICD implantation with the generator positioned in an IM position in comparison with an SC pocket. METHODS AND RESULTS: We analysed 1577 consecutive patients who had undergone S-ICD implantation from 2013 to 2021 and were followed up until December 2021. Subcutaneous patients (n = 290) were propensity matched with patients of the IM group (n = 290), and their outcomes were compared. : During a median follow-up of 28 months, device-related complications were reported in 28 (4.8%) patients and inappropriate shocks were reported in 37 (6.4%) patients. The risk of complication was lower in the matched IM group than in the SC group [hazard ratio 0.41, 95% confidence interval (CI) 0.17-0.99, P = 0.041], as well as the composite of complications and inappropriate shocks (hazard ratio 0.50, 95% CI 0.30-0.86, P = 0.013). The risk of appropriate shocks was similar between groups (hazard ratio 0.90, 95% CI 0.50-1.61, P = 0.721). There was no significant interaction between generator positioning and variables such as gender, age, body mass index, and ejection fraction. CONCLUSION: Our data showed the superiority of the IM S-ICD generator positioning in reducing device-related complications and inappropriate shocks. CLINICAL TRIAL REGISTRATION: Clinical Trial Registration: ClinicalTrials.gov; NCT02275637.

Procedure, management, and outcome of subcutaneous implantable cardioverter-defibrillator extraction in clinical practice.

AIMS: Subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy is expanding rapidly. However, there are few data on the S-ICD extraction procedure and subsequent patient management. The aim of this analysis was to describe the procedure, management, and outcome of S-ICD extractions in clinical practice. METHODS AND RESULTS: We enrolled consecutive patients who required complete S-ICD extraction at 66 Italian centres. From 2013 to 2022, 2718 patients undergoing de novo implantation of an S-ICD were enrolled. Of these, 71 required complete S-ICD system extraction (17 owing to infection). The S-ICD system was successfully extracted in all patients, and no complications were reported; the median procedure duration was 40 (25th-75th percentile: 20-55) min. Simple manual traction was sufficient to remove the lead in 59 (84%) patients, in whom lead-dwelling time was shorter [20 (9-32) months vs. 30 (22-41) months; P = 0.032]. Hospitalization time was short in the case of both non-infectious [2 (1-2) days] and infectious indications [3 (1-6) days]. In the case of infection, no patients required post-extraction intravenous antibiotics, the median duration of any antibiotic therapy was 10 (10-14) days, and the re-implantation was performed during the same procedure in 29% of cases. No complications arose over a median of 21 months. CONCLUSION: The S-ICD extraction was safe and easy to perform, with no complications. Simple traction of the lead was successful in most patients, but specific tools could be needed for systems implanted for a longer time. The peri- and post-procedural management of S-ICD extraction was free from complications and not burdensome for patients and healthcare system. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/Identifier: NCT02275637.

STereotactic Arrhythmia Radioablation (STAR): the Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary consortium (STOPSTORM.eu) and review of current patterns of STAR practice in Europe.

The EU Horizon 2020 Framework-funded Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary (STOPSTORM) consortium has been established as a large research network for investigating STereotactic Arrhythmia Radioablation (STAR) for ventricular tachycardia (VT). The aim is to provide a pooled treatment database to evaluate patterns of practice and outcomes of STAR and finally to harmonize STAR within Europe. The consortium comprises 31 clinical and research institutions. The project is divided into nine work packages (WPs): (i) observational cohort; (ii) standardization and harmonization of target delineation; (iii) harmonized prospective cohort; (iv) quality assurance (QA); (v) analysis and evaluation; (vi, ix) ethics and regulations; and (vii, viii) project coordination and dissemination. To provide a review of current clinical STAR practice in Europe, a comprehensive questionnaire was performed at project start. The STOPSTORM Institutions' experience in VT catheter ablation (83% ≥ 20 ann.) and stereotactic body radiotherapy (59% > 200 ann.) was adequate, and 84 STAR treatments were performed until project launch, while 8/22 centres already recruited VT patients in national clinical trials. The majority currently base their target definition on mapping during VT (96%) and/or pace mapping (75%), reduced voltage areas (63%), or late ventricular potentials (75%) during sinus rhythm. The majority currently apply a single-fraction dose of 25 Gy while planning techniques and dose prescription methods vary greatly. The current clinical STAR practice in the STOPSTORM consortium highlights potential areas of optimization and harmonization for substrate mapping, target delineation, motion management, dosimetry, and QA, which will be addressed in the various WPs.

Ivabradine as a treatment option for junctional ectopic tachycardia in an adult female.

A Junctional ectopic tachycardia diagnosis was performed using two electrophysiological maneuvers in an adult female with a narrow-complex supraventricular tachycardia with a bystander AV-node slow pathway conduction, who previously underwent catheter ablation attempts for an atrio-ventricular nodal re-entrant tachycardia misdiagnosis. The first maneuver was atrial entrainment with an atrial-His-His-atrial response. The second was based on the response to a premature atrial complex delivered at different phases of the tachycardia cycle confirming that anterograde slow pathway conduction and retrograde fast pathway were not involved. Considering that verapamil, diltiazem, bisoprolol + flecainide, and nadolol were ineffective, we tried ivabradine with no sustained arrhythmias during 18-months.

Patient acceptance of subcutaneous versus transvenous defibrillator systems: A multi-center experience.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an effective alternative to the transvenous ICD. No study has yet compared S-ICD and transvenous ICD by assessing patient acceptance as a patient-centered outcome. OBJECTIVE: To evaluate the patient acceptance of the S-ICD and to investigate its association with clinical and implantation variables. In patients with symptomatic heart failure and reduced ejection fraction (HFrEF), the acceptance of the S-ICD was compared with a control group of patients who received a transvenous ICD. METHODS: Patient acceptance was calculated with the Florida Patient Acceptance Survey (FPAS) which measures four factors: return to function (RTF), device-related distress (DRD), positive appraisal (PA), and body image concerns (BIC). The survey was administered 12 months after implantation. RESULTS: 176 patients underwent S-ICD implantation. The total FPAS and the single factors did not differ according to gender, body habitus, or generator positioning. Patients with HFrEF had lower FPAS and RTF. Younger patients showed better RTF (75 [56-94] vs. 56 [50-81], p = .029). Patients who experienced device complications or device therapies showed higher DRD (40 [35-60] vs. 25 [10-50], p = .019). Patients with HFrEF receiving the S-ICD had comparable FPAS, RTF, DRD, and BIC to HFrEF patients implanted with the transvenous ICD while exhibited significantly better PA (88 [75-100] vs. 81 [63-94], p = .02). CONCLUSIONS: Our analysis revealed positive patient acceptance of the S-ICD, even in groups at risk of more distress such as women or patients with thinner body habitus, and regardless of the generator positioning. Among patients receiving ICDs for HFrEF, S-ICD was associated with better PA versus transvenous ICD.

The impact of particle radiotherapy on the functioning of cardiac implantable electronic devices: a systematic review of in vitro and in vivo studies according to PICO criteria.

The number of oncological patients who may benefit from proton beam radiotherapy (PBT) or carbon ion radiotherapy (CIRT), overall referred to as particle radiotherapy (RT), is expected to strongly increase in the next future, as well as the number of cardiological patients requiring cardiac implantable electronic devices (CIEDs). The management of patients with a CIED requiring particle RT deserves peculiar attention compared to those undergoing conventional photon beam RT, mostly due to the potential generation of secondary neutrons by particle beams interactions. Current consensus documents recommend managing these patients as being at intermediate/high risk of RT-induced device malfunctioning regardless of the dose on the CIED and the beam delivery method used, despite the last one significantly affects secondary neutrons generation (very limited neutrons production with active scanning as opposed to the passive scattering technique). The key issues for the current review were expressed in four questions according to the Population, Intervention, Control, Outcome criteria. Three in vitro and five in vivo studies were included. Based on the available data, PBT and CIRT with active scanning have a limited potential to interfere with CIED that has only emerged from in vitro study so far, while a significant potential for neutron-related, not severe, CIED malfunctions (resets) was consistently reported in both clinical and in vitro studies with passive scattering.

Anatomical-based percutaneous left stellate ganglion block in patients with drug-refractory electrical storm and structural heart disease: a single-centre case series.

AIMS: The adoption of percutaneous stellate ganglion blockade for the treatment of drug-refractory electrical storm (ES) has been increasingly reported; however, the time of onset of the anti-arrhythmic effects, the safety of a purely anatomical approach in conscious patients and the additional benefit of repeated procedures remain unclear. METHODS AND RESULTS: This study included consecutive patients undergoing percutaneous left stellate ganglion blockade (PLSGB) in our centre for drug-refractory ES. Lidocaine, bupivacaine, or a combination of both were injected in the vicinity of the left stellate ganglion. Overall, 18 PLSGBs were performed in 11 patients (age 69 ± 13 years; 63.6% men, left ventricular ejection fraction 31.6 ± 16%). Seven patients received only one PLSGB; three underwent two procedures and one required three PLSGB and two continuous infusions to control ventricular arrhythmias (VAs). All PLSGBs were performed with an anatomical approach; lidocaine, alone, or in combination was used in 77.7% of the procedures. The median burden of VAs 1 h after each block was zero compared with five in the hour before (P < 0.001); 83% of the patients were free from VAs; the efficacy at 24 h increased with repeated blocks. The anti-arrhythmic efficacy of PLSGB was not related to anisocoria. No procedure-related complications were reported. CONCLUSION: Anatomical-based PLSGB is a safe and rapidly effective treatment for refractory ES; repeated blocks provide additional benefits. Percutaneous left stellate ganglion blockade should be considered for stabilizing patients to allow further ES management.

Long-term outcome of catheter ablation for atrial fibrillation in patients with severe left atrial enlargement and reduced left ventricular ejection fraction.

AIMS: Data regarding the efficacy of catheter ablation in heart failure patients with severely dilated left atrium and reduced left ventricular ejection fraction (LVEF) are scanty. We sought to assess the efficacy of catheter ablation in patients with reduced LVEF and severe left atrial (LA) enlargement, and to compare it to those patients with preserved left ventricular function and equally dilated left atrium. METHODS AND RESULTS: Three patient groups with paroxysmal or persistent atrial fibrillation (AF) undergoing a first pulmonary vein isolation (PVI) were considered: Group 1 included patients with normal or mildly abnormal LA volume (≤41 mL/m2) and normal LVEF; Group 2 included patients with severe LA enlargement (>48 mL/m2) and normal LVEF; and Group 3 included patients with severe LA enlargement and reduced LVEF. Time to event analysis was used to investigate AF recurrences. The study cohort includes 439 patients; Group 3 had a higher prevalence of cardiovascular risk factors. LA enlargement was associated with a two-fold in risk of AF recurrence, on the contrary only a smaller non-significant increase of 30% was shown with the further addition of LVEF reduction. CONCLUSIONS: The long-term outcome of patients with severe LA dilatation and reduced LVEF is comparable to those with severe LA enlargement but preserved LVEF. Long-term efficacy of PVI is certainly affected by the enlargement of the left atrium, but less so by the addition of a reduced LVEF. CA remains the best strategy for rhythm control both in paroxysmal and persistent AF in this subgroup of patients.

Home delivery of the communicator for remote monitoring of cardiac implantable devices: A multicenter experience during the covid-19 lockdown.

BACKGROUND: During the COVID-19 pandemic in-person visits for patients with cardiac implantable electronic devices should be replaced by remote monitoring (RM), in order to prevent viral transmission. A direct home-delivery service of the RM communicator has been implemented at 49 Italian arrhythmia centers. METHODS: According to individual patient preference or the organizational decision of the center, patients were assigned to the home-delivery group or the standard in-clinic delivery group. In the former case, patients received telephone training on the activation process and use of the communicator. In June 2020, the centers were asked to reply to an ad hoc questionnaire to describe and evaluate their experience in the previous 3 months. RESULTS: RM was activated in 1324 patients: 821 (62%) received the communicator at home and the communicator was activated remotely. Activation required one additional call in 49% of cases, and the median time needed to complete the activation process was 15 min [25th-75th percentile: 10-20]. 753 (92%) patients were able to complete the correct activation of the system. At the time when the questionnaire was completed, 743 (90%) communicators were regularly transmitting data. The service was generally deemed useful (96% of respondents) in facilitating the activation of RM during the COVID-19 pandemic and possibly beyond. CONCLUSIONS: Home delivery of the communicator proved to be a successful approach to system activation, and received positive feedback from clinicians. The increased use of a RM protocol will reduce risks for both providers and patients, while maintaining high-quality care.

Ventricular activation patterns during intrinsic conduction and right ventricular pacing in cardiac resynchronization therapy patients.

BACKGROUND: Cardiac resynchronization therapy (CRT) involves stimulation of both right ventricle (RV) and left ventricle (LV). LV pacing from the sites of delayed electrical activation improves CRT response. The RV-LV conduction is typically measured in intrinsic rhythm. The differences in RV-LV conduction patterns and timing between intrinsic rhythm and during paced RV activation, these differences are not fully understood. METHODS: Enrolled patients were implanted with a de novo CRT device and quadripolar LV lead, with lead implant locations at the implanting physician's discretion. QRS duration and conduction delay between the RV lead and each of the four LV electrodes (D1, M2, M3, and P4) were measured during intrinsic conduction and RV pacing. RESULTS: Conduction measurements were collected from 275 patients across 14 international centers (68 ± 13 years of age, 73% male, 45% ischemic, 158 ± 22 ms QRS duration). Mean RV-LV conduction time was shorter during intrinsic conduction versus RV pacing by 59.6 ms (106.5 ± 36.5 versus 166.1 ± 32.1 ms, p < 0.001). The intra-LV activation delay between the latest and earliest activating LV electrode was also shorter during intrinsic conduction versus RV pacing by 6.6 ms (20.6 ± 13.1 vs. 27.2 ± 21.2 ms, p < 0.001). Intrinsic conduction and RV pacing resulted in a different activation order in 72.7% of patients, and the same LV activation order in 27.3%. CONCLUSIONS: Differences in RV-LV conduction time, intra-LV conduction time, and activation pattern were observed between intrinsic conduction and RV pacing. These findings highlight the importance of evaluating intrinsic versus paced ventricular activation to guide LV pacing site selection in CRT patients.

Leadless pacing in cardiac transplant recipients: Primary results of a multicenter case experience.

About 4.5-20% of patients after heart transplant require pacemaker (PM) implantation. The high infective risk profile and the low probability of pacing dependency make heart-transplanted patients the ideal candidates for a leadless single-chamber PM. We report the first multicenter experience of leadless PM implantation in a series of heart-transplanted patients with a long-term follow-up. Our data confirm the feasibility and acceptable safety of leadless device in this peculiar kind of patients, despite implantation seems to be slightly more challenging with respect to non-transplanted patients. Although more data are required, a leadless single-chamber surveillance PM seems a valuable option for heart-transplanted patients.

Out-of-hospital cardiac arrest due to idiopathic ventricular fibrillation in patients with normal electrocardiograms: results from a multicentre long-term registry.

AIMS: To define the clinical characteristics and long-term clinical outcomes of a large cohort of patients with idiopathic ventricular fibrillation (IVF) and normal 12-lead electrocardiograms (ECGs). METHODS AND RESULTS: Patients with ventricular fibrillation as the presenting rhythm, normal baseline, and follow-up ECGs with no signs of cardiac channelopathy including early repolarization or atrioventricular conduction abnormalities, and without structural heart disease were included in a registry. A total of 245 patients (median age: 38 years; males 59%) were recruited from 25 centres. An implantable cardioverter-defibrillator (ICD) was implanted in 226 patients (92%), while 18 patients (8%) were treated with drug therapy only. Over a median follow-up of 63 months (interquartile range: 25-110 months), 12 patients died (5%); in four of them (1.6%) the lethal event was of cardiac origin. Patients treated with antiarrhythmic drugs only had a higher rate of cardiovascular death compared to patients who received an ICD (16% vs. 0.4%, P = 0.001). Fifty-two patients (21%) experienced an arrhythmic recurrence. Age ≤16 years at the time of the first ventricular arrhythmia was the only predictor of arrhythmic recurrence on multivariable analysis [hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.18-0.92; P = 0.03]. CONCLUSION: Patients with IVF and persistently normal ECGs frequently have arrhythmic recurrences, but a good prognosis when treated with an ICD. Children are a category of IVF patients at higher risk of arrhythmic recurrences.