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Introduction:The recently developed second-generation subcutaneous implantable cardioverter defibrillator (S-ICD) and the intermuscular two-incision implantation technique demonstrate potential favorable features that reduce inappropriate shocks and complications. However, data concerning large patient populations are lacking.The aim of this multicentre prospective study was to evaluate the safety and outcome of second-generation S-ICD using the intermuscular two-incision technique in a large population study. Methods and Results:The study population included 101 consecutive patients (75% male; mean age, 45 ± 13 years) who received second-generation S-ICD (EMBLEM; Boston Scientific, Marlborough, MA) implantation using the intermuscular twoincision technique as an alternative to the standard implantation technique. Twenty nine (29%) patients were implanted for secondary prevention. Twenty four (24%) patients had a previously implanted transvenous ICD. All patients were implanted without any procedure-related complications. Defibrillation testing was performed in 80 (79%) patients, and ventricular tachycardia was successfully converted at less than or equal to 65 J in 98.75% (79/80) of patients without pulse generator adjustments.During a median follow-up of 21 ± 10 months, no complications requiring surgical revision or local or systemic device-related infections were observed. Ten patients Disclosures: None.(9.9%) received appropriate and successful shocks for ventricular arrhythmias. Three (2.9%) patients experienced inappropriate shocks due to oversensing the cardiac signal (n = 1), noncardiac signal (n = 1), and a combination of both cardiac and noncardiac signals (n = 1), with one patient requiring device explantation. No patients required device explantation due to antitachycardia pacing indications.Conclusions: According to our multicentre study, second-generation S-ICD implanted with the intermuscular two-incision technique is an available safe combination and appears to be associated with a low risk of complications, such as inappropriate shocks. K E Y W O R D S implantable cardioverter defibrillator, intermuscular technique, subcutaneous implantable cardioverter defibrillator, two-incision technique 1 | INTRODUCTION Current guidelines state that the subcutaneous implantable cardioverter defibrillator (S-ICD) represents a therapeutic option for patients at highrisk of sudden cardiac death, in whom pacing or cardiac resynchronization therapy is not required. 1 The recent development of an entirely S-ICD constitutes a major evolution of defibrillator technology, and there has been consistent clinical evidence regarding its safety. 2-4 The standard S-ICD implantation technique requires three incisions and the placement of a midaxillary pulse generator under subcutaneous tissue. However, various alternative implantation techniques have been explored, 3 including the intermuscular two-incision technique. 4-6 New techniques may reduce complications such as erosion while improving the esthetic appeal of the puls...

Arrhythmogenic cardiomyopathy (AC) is a heart muscle disease characterized by a scarred ventricular myocardium with a distinctive propensity to ventricular arrhythmias (VAs) and sudden cardiac death, especially in young athletes. Arrhythmogenic right ventricular cardiomyopathy (ARVC) represents the best characterized variant of AC, with a peculiar genetic background, established diagnostic criteria and management guidelines; however, the identification of nongenetic causes of the disease, combined with the common demonstration of biventricular and left-dominant forms, has led to coin the term of “arrhythmogenic cardiomyopathy”, to better define the broad spectrum of the disease phenotypic expressions. The genetic basis of AC are pathogenic mutations in genes encoding the cardiac desmosomes, but also non-desmosomal and nongenetic variants were reported in patients with AC, some of which showing overlapping phenotypes with other non-ischemic diseases. The natural history of AC is characterized by VAs and progressive deterioration of cardiac performance. Different phases of the disease are recognized, each characterized by pathological and clinical features. Arrhythmic manifestations are age-related: Ventricular fibrillation and SCD are more frequent in young people, while sustained ventricular tachycardia is more common in the elderly, depending on the different nature of the myocardial lesions. This review aims to address the genetic basis, the clinical course and the phenotypic variants of AC.

Arrhythmogenic cardiomyopathy (ACM) is a genetically determined heart muscle disease characterized by fibro-fatty myocardial replacement, clinically associated with malignant ventricular arrhythmias and sudden cardiac death. Originally described a disease with a prevalent right ventricular (RV) involvement, subsequently two other phenotypes have been recognized, such as the left dominant and the biventricular phenotypes, for which a recent International Expert consensus document provided upgrade diagnostic criteria (the 2020 “Padua Criteria”). In this novel workup for the diagnosis of the entire spectrum of phenotypic variants of ACM, including left ventricular (LV) variants, cardiac magnetic resonance (CMR) has emerged as the cardiac imaging technique of choice, due to its capability of detailed morpho-functional and tissue characterization evaluation of both RV and LV. In this review, the key role of CMR in the diagnosis of ACM is outlined, including the supplemental value for the characterization of the disease variants. An ACM-specific CMR study protocol, as well as strengths and weaknesses of each imaging technique, is also provided. Key Points • Arrhythmogenic cardiomyopathy includes three different phenotypes: dominant right, biventricular, and dominant left. • In 2020, diagnostic criteria have been updated and cardiac magnetic resonance has emerged as the cardiac imaging technique of choice. • This aim of this review is to provide an update of the current state of art regarding the use of CMR in ACM, with a particular focus on novel diagnostic criteria, CMR protocols, and prognostic significance of CMR findings in ACM.

Arrhythmogenic cardiomyopathy (ACM) is an inheritable heart muscle disease characterised pathologically by fibrofatty myocardial replacement and clinically by ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Although, in its original description, the disease was believed to predominantly involve the right ventricle, biventricular and left-dominant variants, in which the myocardial lesions affect in parallel or even mostly the left ventricle, are nowadays commonly observed. The clinical management of these patients has two main purposes: the prevention of SCD and the control of arrhythmic and heart failure (HF) events. An implantable cardioverter defibrillator (ICD) is the only proven lifesaving treatment, despite significant morbidity because of device-related complications and inappropriate shocks. Selection of patients who can benefit the most from ICD therapy is one of the most challenging issues in clinical practice. Risk stratification in ACM patients is mostly based on arrhythmic burden and ventricular dysfunction severity, although other clinical features resulting from electrocardiogram and imaging modalities such as cardiac magnetic resonance may have a role. Medical therapy is crucial for treatment of VAs and the prevention of negative ventricular remodelling. In this regard, the efficacy of novel anti-HF molecules and drugs acting on the inflammatory pathway in patients with ACM is, to date, unknown. Catheter ablation represents an effective strategy to treat ventricular tachycardia relapses and recurrent ICD shocks. The present review will address the current strategies for prevention of SCD and treatment of VAs and HF in patients with ACM.