An annotation-independent algorithm based on electrogram characteristics to guide the identification of ventricular tachycardia isthmuses in patients with structural heart disease.

BACKGROUND: Criteria such as electrograms voltage or late potentials have been largely utilized in the past to help identify areas of substrate maps that are within the ventricular tachycardia (VT) isthmus; yet their specificity and positive predictive value are quite low. The Lumipoint fractionation tool of the Rhythmia system illuminates regions with fractionated electrograms irrespective of their timing and annotation. We aimed to ascertain whether the use of this tool can rapidly identify areas within VT isthmuses from substrate maps. METHODS: Thirty patients with structural cardiomyopathy in whom a complete right ventricular-paced substrate map and a full reconstruction of the diastolic isthmus during VT could be obtained were enrolled. The VT isthmus border was projected on each substrate map to verify whether the areas illuminated by Lumipoint fell within those borders. The behavior of the electrograms detected at the illuminated areas of the substrate maps was studied during a right ventricular drive train and extra stimulus protocol: if the near field potentials showed a delayed conduction after a single extra stimulus, defined as a minimum of 10 ms increase of the time interval between the far field and the near field activation measured during the drive train, the electrogram was said to have a "decremental" behavior. RESULTS: The logistic analysis showed that areas with fractionated electrograms illuminated by the Lumipoint software and showing the greatest decremental behavior fell within the VT isthmus borders (OR = 1.66, CI: 1.41-1.75, p<0.001; OR=1.57 CI: 1.32-1.72, p<0.001, respectively) with a sensitivity, specificity, and positive predictive value of 87%, 96%, and 97%, respectively. CONCLUSIONS: Fractionated electrograms illuminated by the automated Lumipoint software on right ventricular-paced substrate maps showing the greatest decremental behavior fall within the VT isthmus borders with a probability of 0.97, irrespective of their timing, annotation, or voltage, without any need for subjective assessment of their involvement in slow conduction areas.

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.

Opportunities and drawbacks of the subcutaneous defibrillator across different clinical settings.

INTRODUCTION: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an established therapy for the prevention of sudden cardiac death (SCD) and an alternative to a transvenous implantable cardioverter-defibrillator system in selected patients. Beyond randomized clinical trials, many observational studies have described the clinical performance of S-ICD across different subgroups of patients. AREAS COVERED: Our review aimed to describe the opportunities and drawbacks of the S-ICD, focusing on their use in special populations and across different clinical settings. EXPERT OPINION: The choice to implant S-ICD should be based on the patient's tailored approach, which takes into account the adequate S-ICD screening at rest or during stress, the infective risk, the ventricular arrhythmia susceptibility, the progressive nature of the underlying disease, the work or sports activity, and the risk of lead-related complications.

[2020 Catheter Ablation Registry of the Italian Association of Arrhythmology and Cardiac Pacing]. / Registro Italiano Ablazioni 2020. Associazione Italiana di Aritmologia e Cardiostimolazione.

BACKGROUND: This report describes the findings of the 2020 Italian Catheter Ablation Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC). METHODS: Data collection was retrospective. A standardized questionnaire was completed by each of the participating centers. RESULTS: A total of 10 378 ablation procedures were performed by 66 institutions. Most centers (70%) have an electrophysiology laboratory, and 23% a hybrid cardiac surgery laboratory. All centers have a 3D mapping system. The median number of electrophysiologists and nurses involved in the electrophysiology laboratory was 3.5 and 3, respectively. An electrophysiology technician was involved in 35% of all centers. In 88.2% of cases, catheter ablation was performed for supraventricular arrhythmias; the most frequently treated arrhythmia was atrial fibrillation (39.4%), followed by atrioventricular nodal reentrant tachycardia (18.6%), and common atrial flutter (10.6%). In 72.9% of patients, catheter ablation was performed using a 3D mapping system, with a "near-zero" fluoroscopic approach in 37.7% of all patients. CONCLUSIONS: The 2020 Italian Catheter Ablation Registry confirmed that the electrophysiology activity was markedly affected by the COVID-19 pandemic; atrial fibrillation is the most frequently treated arrhythmia with an increasing number of procedures performed with a 3D mapping system and a "near-zero" approach.

Subcutaneous versus transvenous implantable cardioverter-defibrillator among drug-induced type-1 ECG pattern Brugada syndrome: a propensity score matching analysis from IBRYD study.

No real-world data are available about the complications rate in drug-induced type 1 Brugada Syndrome (BrS) patients with an implantable cardioverter-defibrillator (ICD). Aim of our study is to compare the device-related complications, infections, and inappropriate therapies among drug-induced type 1 BrS patients with transvenous- ICD (TV-ICD) versus subcutaneous-ICD (S-ICD). Data for this study were sourced from the IBRYD (Italian BRugada sYnDrome) registry which includes 619 drug-induced type-1 BrS patients followed at 20 Italian tertiary referral hospitals. For the present analysis, we selected 258 consecutive BrS patients implanted with ICD. 198 patients (76.7%) received a TV-ICD, while 60 a S-ICD (23.4%). And were followed-up for a median time of 84.3 [46.5-147] months. ICD inappropriate therapies were experienced by 16 patients (6.2%). 14 patients (7.1%) in the TVICD group and 2 patients (3.3%) in S-ICD group (log-rank P = 0.64). ICD-related complications occurred in 31 patients (12%); 29 (14.6%) in TV-ICD group and 2 (3.3%) in S-ICD group (log-rank P = 0.41). ICD-related infections occurred in 10 patients (3.88%); 9 (4.5%) in TV-ICD group and 1 (1.8%) in S-ICD group (log-rank P = 0.80). After balancing for potential confounders using the propensity score matching technique, no differences were found in terms of clinical outcomes between the two groups. In a real-world setting of drug-induced type-1 BrS patients with ICD, no significant differences in inappropriate ICD therapies, device-related complications, and infections were shown among S-ICD vs TV-ICD. However, a reduction in lead-related complications was observed in the S-ICD group. In conclusion, our evidence suggests that S-ICD is at least non-inferior to TV-ICD in this population and may also reduce the risk of lead-related complications which can expose the patients to the necessity of lead extractions.

The "Defibrillation Testing, Why Not?" survey. Testing of subcutaneous and transvenous defibrillators in the Italian clinical practice.

BACKGROUND: Defibrillation testing (DT) can be omitted in patients undergoing transvenous implantable cardioverter-defibrillator (T-ICD) implantation, but it is still recommended for patients at risk for a high defibrillation threshold and for ICD generator changes. Moreover, DT is still recommended on implantation of subcutaneous ICD (S-ICD). The aim of the present survey was to analyze the current practice of DT during T-ICD and S-ICD implantations. METHODS: In March 2021, an ad hoc questionnaire on the current performance of DT and the standard practice adopted during testing was completed at 72 Italian centers implanting S-ICD and T-ICD. RESULTS: 48 (67%) operators reported never performing DT during de-novo T-ICD implantations, while no operators perform it systematically. The remaining respondents perform it for patients at risk for a high defibrillation threshold. DT is never performed at T-ICD generator change. At the time of de-novo S-ICD implantation, DT is never performed by 9 (13%) operators and performed systematically by 48 (66%). The remaining operators frequently omit DT in patients with more severe systolic dysfunction. DT is not performed at S-ICD generator change by 92% of operators. DT is conducted by delivering a first shock energy of 65 J by 60% of operators, while the remaining 40% test lower energy values. CONCLUSIONS: In current clinical practice, most operators omit DT at T-ICD implantation, even when still recommended in the guidelines. DT is also frequently omitted at S-ICD implantation, and a wide variability exists among operators in the procedures followed during DT.

[2019 Catheter Ablation Registry of the Italian Association of Arrhythmology and Cardiac Pacing]. / Registro Italiano Ablazioni 2019. Associazione Italiana di Aritmologia e Cardiostimolazione.

BACKGROUND: This report describes the findings of the 2019 Italian Catheter Ablation Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC). METHODS: Data collection was retrospective. A standardized questionnaire was completed by each of the participating centers. RESULTS: A total of 15 201 ablation procedures were performed by 91 institutions. Most (78%) of the centers has one electrophysiology laboratory, and 17% of them has a hybrid cardiac surgery laboratory. Almost all (98%) centers have a 3D mapping system. The median number of electrophysiologists and nurses involved in the electrophysiology laboratory was 3 and an electrophysiology technician was involved in 30% of all centers. In 88.4% of cases, ablations were performed for supraventricular arrhythmias, and among these the most frequently treated arrhythmia was atrial fibrillation (32.9%), followed by atrioventricular nodal reentrant tachycardia (23.9%), and common atrial flutter (11.7%). In 10 256 (67.4%) patients catheter ablation was performed by means of a 3D mapping system, with a "near-zero" fluoroscopic approach in 4626 (30.4%) of all patients. CONCLUSIONS: The 2019 Italian Catheter Ablation Registry confirmed that atrial fibrillation is the most commonly treated arrhythmia in the ablation centers with an increasing number of procedures performed with a 3D mapping system and a "near-zero" approach.

Cardiac electrophysiology and pacing educational and training needs among early-career cardiologists: a national survey of the Young Committee of the Italian Association of Arrhythmology and Cardiac Pacing.

BACKGROUND: Over the past three decades, cardiac electrophysiology and pacing, including device therapy and catheter ablation of arrhythmias, has rapidly developed as a subspecialty in cardiology. Currently, there is no clear perception about the needs in cardiac electrophysiology and pacing among early-career cardiologists. METHODS: To address these concerns, the Young Committee of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) carried out a survey among those under the age of 40 years to obtain detailed information on practical activities and formal lessons during the fellowship in cardiology and their satisfaction and proficiency level at the end of the fellowship. RESULTS: We obtained 334 answers to the survey. In invasive cardiac electrophysiology and pacing, the percentage of participants attending the activity for a longer time (3-6 months) is lower compared with those in noninvasive subspecialties. About 40% of participants did not receive lessons on interventional cardiology, cardiac electrophysiology and pacing. On the contrary, 71% of participants received an adequate number of lessons on clinical arrhythmology. The vast majority of the participants expressed satisfaction for the education received in the echocardiographic, cardiac interventional laboratories and clinical arrhythmology, but about half of the participants were unsatisfied with the education received in cardiac electrophysiology and pacing. In interventional arrhythmology, the majority of the participants declare their lack of proficiency with two peaks for more complex procedures, namely interventional electrophysiology procedures (82%) and cardiac resynchronization therapy (CRT) procedures (76%). CONCLUSION: The present survey among Italian early-career cardiologists suggests that the majority of participants consider themselves not confident in performing cardiac electrophysiology and pacing procedures. Due to the complexity of the treatment for heart rhythm disorders and the long learning curve, structured additional training in cardiac electrophysiology and pacing procedures is required after cardiology fellowship.

Lead Abandonment and Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD) Implantation in a Cohort of Patients With ICD Lead Malfunction.

Background: When an implantable-cardioverter defibrillator (ICD) lead becomes non-functional, a recommendation currently exists for either lead abandonment or removal. Lead abandonment and subcutaneous ICD (S-ICD) implantation may represent an additional option for patients who do not require pacing. The aim of this study was to investigate the outcomes of a strategy of lead abandonment and S-ICD implantation in the setting of lead malfunction. Methods: We analyzed all consecutive patients who underwent S-ICD implantation after abandonment of malfunctioning leads and compared their outcomes with those of patients who underwent extraction and subsequent reimplantation of a single-chamber transvenous ICD (T-ICD). Results: Forty-three patients underwent S-ICD implantation after abandonment of malfunctioning leads, while 62 patients underwent extraction and subsequent reimplantation of a new T-ICD. The two groups were comparable. In the extraction group, no major complications occurred during extraction, while the procedure failed and an S-ICD was implanted in 4 patients. During a median follow-up of 21 months, 3 major complications or deaths occurred in the S-ICD group and 11 in the T-ICD group (HR 1.07; 95% CI 0.29-3.94; P = 0.912). Minor complications were 4 in the S-ICD group and 5 in the T-ICD group (HR 2.13; 95% CI 0.49-9.24; P = 0.238). Conclusions: In the event of ICD lead malfunction, extraction avoids the potential long-term risks of abandoned leads. Nonetheless the strategy of lead abandonment and S-ICD implantation was feasible and safe, with no significant increase in adverse outcomes, and may represent an option in selected clinical settings. Further studies are needed to fully understand the potential risks of lead abandonment. Clinical Trial Registration: URL: ClinicalTrials.gov Identifier: NCT02275637.

A very long-term observation of a family with dilated cardiomyopathy and overlapping phenotype from lamin A/C mutation.

AIMS: We aim to describe one of the longest longitudinal follow-ups reported so far (>22 years), concerning a whole family affected by a missense lamin A/C mutation (Arg60Gly), which manifested as an overlapping phenotype with cardiac and extracardiac involvement over time. METHODS: Starting from the family history, two generations of that family were prospectively observed, from 1997 until 2020. At baseline, four individuals with dilated cardiomyopathy and cardiac conduction defects showed the same mutation. This was also found in three young individuals, phenotypically unaffected at baseline assessment. RESULTS: The prolonged clinical and laboratory evaluation has shown the evolution of an overlapping phenotype in which cardiac alterations have been associated with lipodystrophy and neurological manifestations. In the first observed generation, the prognosis was negatively affected by the progression of heart failure and lipodystrophy, whereas in the second generation the first phenotypic manifestations became evident after the 2nd decade. Cardiac magnetic resonance played a relevant role in the early detection of cardiac alteration. Right bundle branch block was another sign of initial phenotypical expression. CONCLUSION: In lamin A/C gene mutation carriers, a strict, multidisciplinary follow-up allows the opportunity to monitor the progress of the disease and to intervene precociously with the best available treatments.

Right ventricular function assessed by cardiac magnetic resonance predicts the response to resynchronization therapy.

BACKGROUND AND AIM: Cardiac resynchronization therapy (CRT) reduces mortality and morbidity in chronic heart failure symptomatic patients with broad QRS who are already undergoing optimal medical treatment. However, approximately one-third of implanted patients do not show any benefit from this treatment. Right ventricle (RV) dysfunction leads to a worse outcome in patients with heart failure, but its role in predicting the response to CRT has shown conflicting results. The purpose of our study was to investigate how the RV function, assessed by cardiac magnetic resonance (CMR), could influence the outcome of heart failure patients treated with CRT. METHODS AND RESULTS: We retrospectively enrolled 72 heart failure patients, 38 affected by dilated cardiomyopathy (DCM) and 34 by ischemic dysfunction, with left bundle branch block, QRS greater than 120 ms and standard indications to CRT. We defined the response to CRT as an improvement of at least 10% of the left ventricular ejection fraction (LVEF) or at least one of the NYHA functional classes. We stratified the population into two groups based on the right ventricle ejection fraction (RVEF) at CMR: group 1 RVEF at least 55% (n = 32), group 2 RVEF less than 55% (n = 40). After a mean follow-up of 38 ±â€Š12 months, 44 patients (61%) were considered responders whereas 28 (39%) did not show any benefit. Patients in group 1 had a higher rate of response to CRT (75 vs. 50%, P = 0.03). At the univariate analysis RVEF [54 vs. 43%; confidence interval (CI) = 0.907-0.980; hazard ratio = 0.943; P = 0.003], RV end-systolic volume (56 vs. 84 ml; CI = 1.005-1.034; hazard ratio = 1.019; P = 0.008) and tricuspid annular plane systolic excursion (TAPSE) (16.4 vs. 14 mm; CI 0.745-0.976; heart rate = 0.853; P = 0.021) were the parameters most strongly associated with the response to CRT. Male sex, atrial fibrillation, and older age also negatively influenced the outcome. At a multivariate model, RVEF and older age remained significant. CONCLUSION: In our experience, patients with RV dysfunction less likely benefited from CRT. RV assessment, studied with CMR, appears to be a good predictor of the response to biventricular stimulation.

Nationwide survey on the current practice of ventricular tachycardia ablation.

METHODS: We performed a nationwide survey on the current practice of ventricular tachycardia catheter ablation in Italy during the year 2016. RESULTS: Among 145 operators participating in the survey, 58 (40.0%) did not perform any ventricular tachycardia ablation in 2016. Among those performing ventricular tachycardia ablation, 9 operators (6.2%) performed only right ventricular endocardial catheter ablation, 52 (35.9%) performed endocardial catheter ablation both in the right and left ventricle (LV) and 26 (17.9%) performed both endocardial and epicardial LV catheter ablations. Seventy operators (89.7%) among the 78 performing LV and epicardial ablations treated patients with ischemic cardiomyopathy; ablations in the setting of other causes were less frequently performed. The following were considered as minimum requirements for ventricular tachycardia ablation: presence of a three-dimensional mapping system (120 operators, 82.8%), ICU in the hospital (118 operators, 81.4%), operator's training in high volume centers (93 operators, 64.1%). Twenty-eight operators (19.3%) performed catheter ablation in patients with electrical storm only after hemodynamic stabilization, 41 operators (28.3%) also during the acute phase and 9 operators (6.2%) never performed catheter ablation in electrical storm patients; the remaining 67 operators did not perform ventricular tachycardia ablation at all, or performed ablations only in the right ventricle. CONCLUSION: The present survey provides a snapshot of the current invasive treatment of ventricular tachycardia by catheter ablation. The procedure, especially in the setting of ischemic cardiomyopathy, is performed nationwide. Complex cases, including those with electrical storm, should be managed within a preestablished integrated network of regional referral centers able to transfer patients as soon as possible.

Use and outcomes of subcutaneous implantable cardioverter-defibrillator (ICD) after transvenous ICD extraction: An analysis of current clinical practice and a comparison with transvenous ICD reimplantation.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) does not require the insertion of any leads into the cardiovascular system. OBJECTIVE: The aims of the study were to describe current practice and to measure outcomes associated with S-ICD or standard single-chamber transvenous ICD (TV-ICD) use after TV-ICD explantation. METHODS: We analyzed all consecutive patients who underwent transvenous extraction of an ICD and subsequent implantation of an S-ICD or a single-chamber TV-ICD at 12 Italian centers from 2011 to 2017. RESULTS: A total of 229 patients were extracted and subsequently reimplanted with an S-ICD (90; 39%) or a single-chamber TV-ICD (139; 61%). S-ICD implantation increased from 9% in 2011 to 85% in 2017 (P < .001). Patients reimplanted with an S-ICD were younger (53 ± 13 years vs 60 ± 18 years; P = .011) and more frequently had undergone extraction owing to infection (73% vs 52%; P < .001). The rates of complications at follow-up were comparable between groups (hazard ratio 0.97; 95% confidence interval 0.49-1.92; P = .940). No lead failures, systemic infections, or system-related deaths occurred in the S-ICD group. In the TV-ICD group, 1 lead fracture occurred and 2 systemic infections were reported, resulting in death in 1 case. In the S-ICD group, the rate of complications was lower when the generator was positioned in a sub- or intermuscular pocket (hazard ratio 0.21; 95% confidence interval 0.05-0.87; P = .048). CONCLUSION: Our results show an increasing use of S-ICD over the years in patients undergoing TV-ICD explantation. An S-ICD is preferably adopted in young patients, mostly in the case of infection. The complication rate was comparable between groups and decreased when a sub- or intermuscular S-ICD generator position was adopted.