Multimodality imaging in arrhythmogenic cardiomyopathy - From diagnosis to management.

Arrhythmogenic Cardiomyopathy (AC), an inherited cardiac disorder characterized by myocardial fibrofatty replacement, carries a significant risk of sudden cardiac death (SCD) due to ventricular arrhythmias. A comprehensive multimodality imaging approach, including echocardiography, cardiac magnetic resonance imaging (CMR), and cardiac computed tomography (CCT), allows for accurate diagnosis, effective risk stratification, vigilant monitoring, and appropriate intervention, leading to improved patient outcomes and the prevention of SCD. Echocardiography is primary tool ventricular morphology and function assessment, CMR provides detailed visualization, CCT is essential in early stages for excluding congenital anomalies and coronary artery disease. Echocardiography is preferred for follow-up, with CMR capturing changes over time. The strategic use of these imaging methods aids in confirming AC, differentiating it from other conditions, tracking its progression, managing complications, and addressing end-stage scenarios.

Multimodality Imaging in Advanced Heart Failure for Diagnosis, Management and Follow-Up: A Comprehensive Review.

Advanced heart failure (AHF) presents a complex landscape with challenges spanning diagnosis, management, and patient outcomes. In response, the integration of multimodality imaging techniques has emerged as a pivotal approach. This comprehensive review delves into the profound significance of these imaging strategies within AHF scenarios. Multimodality imaging, encompassing echocardiography, cardiac magnetic resonance imaging (CMR), nuclear imaging and cardiac computed tomography (CCT), stands as a cornerstone in the care of patients with both short- and long-term mechanical support devices. These techniques facilitate precise device selection, placement, and vigilant monitoring, ensuring patient safety and optimal device functionality. In the context of orthotopic cardiac transplant (OTC), the role of multimodality imaging remains indispensable. Echocardiography offers invaluable insights into allograft function and potential complications. Advanced methods, like speckle tracking echocardiography (STE), empower the detection of acute cell rejection. Nuclear imaging, CMR and CCT further enhance diagnostic precision, especially concerning allograft rejection and cardiac allograft vasculopathy. This comprehensive imaging approach goes beyond diagnosis, shaping treatment strategies and risk assessment. By harmonizing diverse imaging modalities, clinicians gain a panoramic understanding of each patient's unique condition, facilitating well-informed decisions. The aim is to highlight the novelty and unique aspects of recently published papers in the field. Thus, this review underscores the irreplaceable role of multimodality imaging in elevating patient outcomes, refining treatment precision, and propelling advancements in the evolving landscape of advanced heart failure management.

Coronary artery calcium score: we know where we are but not where we may be.

Cardiac computed tomography angiography (CCTA) has emerged as a cost-effective and time-saving technique for excluding coronary artery disease. One valuable tool obtained by CCTA is the coronary artery calcium (CAC) score. The use of CAC scoring has shown promise in the risk assessment and stratification of cardiovascular disease. CAC scores can be complemented by plaque analysis to assess vulnerable plaque characteristics and further refine risk assessment. This paper aims to provide a comprehensive understanding of the value of the CAC as a prognostic tool and its implications for patient risk assessment, treatment strategies, and outcomes. CAC scoring has demonstrated superior ability in stratifying patients, especially asymptomatic individuals, compared to traditional risk factors and scoring systems. The main evidence suggests that individuals with a CAC score of 0 have a good long-term prognosis, while an elevated CAC score is associated with increased cardiovascular risk. Finally, the clinical power of CAC scoring and the development of new models for risk stratification could be enhanced by machine learning algorithms.

New Non-Invasive Imaging Technologies in Cardiac Transplant Follow-Up: Acquired Evidence and Future Options.

Heart transplantation (HT) is the established treatment for end-stage heart failure, significantly enhancing patients' survival and quality of life. To ensure optimal outcomes, the routine monitoring of HT recipients is paramount. While existing guidelines offer guidance on a blend of invasive and non-invasive imaging techniques, certain aspects such as the timing of echocardiographic assessments and the role of echocardiography or cardiac magnetic resonance (CMR) as alternatives to serial endomyocardial biopsies (EMBs) for rejection monitoring are not specifically outlined in the guidelines. Furthermore, invasive coronary angiography (ICA) is still recommended as the gold-standard procedure, usually performed one year after surgery and every two years thereafter. This review focuses on recent advancements in non-invasive and contrast-saving imaging techniques that have been investigated for HT patients. The aim of the manuscript is to identify imaging modalities that may potentially replace or reduce the need for invasive procedures such as ICA and EMB, considering their respective advantages and disadvantages. We emphasize the transformative potential of non-invasive techniques in elevating patient care. Advanced echocardiography techniques, including strain imaging and tissue Doppler imaging, offer enhanced insights into cardiac function, while CMR, through its multi-parametric mapping techniques, such as T1 and T2 mapping, allows for the non-invasive assessment of inflammation and tissue characterization. Cardiac computed tomography (CCT), particularly with its ability to evaluate coronary artery disease and assess graft vasculopathy, emerges as an integral tool in the follow-up of HT patients. Recent studies have highlighted the potential of nuclear myocardial perfusion imaging, including myocardial blood flow quantification, as a non-invasive method for diagnosing and prognosticating CAV. These advanced imaging approaches hold promise in mitigating the need for invasive procedures like ICA and EMB when evaluating the benefits and limitations of each modality.

Scarring/arrhythmogenic cardiomyopathy.

The designation of 'arrhythmogenic cardiomyopathy' reflects the evolving concept of a heart muscle disease affecting not only the right ventricle (ARVC) but also the left ventricle (LV), with phenotypic variants characterized by a biventricular (BIV) or predominant LV involvement (ALVC). Herein, we use the term 'scarring/arrhythmogenic cardiomyopathy (S/ACM)' to emphasize that the disease phenotype is distinctively characterized by loss of ventricular myocardium due to myocyte death with subsequent fibrous or fibro-fatty scar tissue replacement. The myocardial scarring predisposes to potentially lethal ventricular arrhythmias and underlies the impairment of systolic ventricular function. S/ACM is an 'umbrella term' which includes a variety of conditions, either genetic or acquired (mostly post-inflammatory), sharing the typical 'scarring' phenotypic features of the disease. Differential diagnoses include 'non-scarring' heart diseases leading to either RV dilatation from left-to-right shunt or LV dilatation/dysfunction from a dilated cardiomyopathy. The development of 2020 upgraded criteria ('Padua criteria') for diagnosis of S/ACM reflected the evolving clinical experience with the expanding spectrum of S/ACM phenotypes and the advances in cardiac magnetic resonance (CMR) imaging. The Padua criteria aimed to improve the diagnosis of S/ACM by incorporation of CMR myocardial tissue characterization findings. Risk stratification of S/ACM patients is mostly based on arrhythmic burden and ventricular dysfunction severity, although other ECG or imaging parameters may have a role. Medical therapy is crucial for treatment of ventricular arrhythmias and heart failure. Implantable cardioverter defibrillator (ICD) is the only proven life-saving treatment, despite its 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.

Spontaneous coronary artery dissection: the emerging role of coronary computed tomography.

Spontaneous coronary artery dissection (SCAD) is a cause of acute coronary syndrome and myocardial infarction, more frequent among young women. Invasive coronary angiography (ICA) is the gold standard for the diagnosis of SCAD, although the risk of propagating dissection flap is considerable. Therefore, coronary computed tomography angiography (CCTA) is an emerging alternative modality to diagnose SCAD with the advantage of being a non-invasive technique. Clinicians should be aware of the predisposing conditions and pathophysiology to raise the pre-test probability of SCAD and select the most appropriate diagnostic tools. In recent times, improvements in spatial and temporal resolution and the use of semi-automated software providing quantitative assessment make CCTA a valid alternative to ICA also for the follow-up. Moreover, CCTA may be helpful to screen and evaluate extra-coronary arteriopathies closely related to SCAD. In this review, we illustrate the current and the potential role of CCTA in the diagnosis of SCAD, highlighting advantages and disadvantages of this imaging modality compared to ICA.

Cardiac magnetic resonance imaging of arrhythmogenic cardiomyopathy: evolving diagnostic perspectives.

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.

Pregnancy in Women with Arrhythmogenic Left Ventricular Cardiomyopathy.

BACKGROUND: In the last few years, a phenotypic variant of arrhythmogenic cardiomyopathy (ACM) labeled arrhythmogenic left ventricular cardiomyopathy (ALVC) has been defined and researched. This type of cardiomyopathy is characterized by a predominant left ventricular (LV) involvement with no or minor right ventricular (RV) abnormalities. Data on the specific risk and management of pregnancy in women affected by ALVC are, thus far, not available. We have sought to characterize pregnancy course and outcomes in women affected by ALVC through the evaluation of a series of childbearing patients. METHODS: A series of consecutive female ALVC patients were analyzed in a cross-sectional, retrospective study. Study protocol included 12-lead ECG assessments, 24-h Holter ECG evaluations, 2D-echocardiogram tests, cardiac magnetic resonance assessments, and genetic analysis. Furthermore, the long-term disease course of childbearing patients was compared with a group of nulliparous ALVC women. RESULTS: A total of 35 patients (mean age 45 ± 9 years, 51% probands) were analyzed. Sixteen women (46%) reported a pregnancy, for a total of 27 singleton viable pregnancies (mean age at first childbirth 30 ± 9 years). Before pregnancy, all patients were in the NYHA class I and none of the patients reported a previous heart failure (HF) episode. No significant differences were found between childbearing and nulliparous women regarding ECG features, LV dimensions, function, and extent of late enhancement. Overall, 7 patients (20%, 4 belonging to the childbearing group) experienced a sustained ventricular tachycardia and 2 (6%)-one for each group-showed heart failure (HF) episodes. The analysis of arrhythmia-free survival patients did not show significant differences between childbearing and nulliparous women. CONCLUSIONS: In a cohort of ALVC patients without previous episodes of HF, pregnancy was well tolerated, with no significant influence on disease progression and degree of electrical instability. Further studies on a larger cohort of women with different degrees of disease extent and genetic background are needed in order to achieve a more comprehensive knowledge regarding the outcome of pregnancy in ALVC patients.

Impact of coronavirus disease 19 outbreak on arrhythmic events and mortality among implantable cardioverter defibrillator patients followed up by remote monitoring: a single center study from the Veneto region of Italy.

BACKGROUND: The 2020 severe acute respiratory syndrome coronavirus 2 outbreak entailed reduced availability of traditional (in-office) cardiology consultations. Remote monitoring is an alternative way of caring that may potentially mitigate the negative effects of the epidemic to the care of cardiovascular diseases. We evaluated the outcome of implantable cardioverter defibrillator (ICD) carriers followed up remotely in 2020 (epidemic period) versus 2019 (control). METHODS: We included all patients with an ICD who remained remotely monitored from the beginning to the end of each year. The combined end point included: new-onset atrial fibrillation; sustained ventricular tachycardia >170 bpm without ICD intervention; appropriate ICD intervention (either shock or antitachycardia pacing); any-cause death. Multiple events in the same patients were counted separately if occurring ≥48 h apart. RESULTS: In 2020, 52 end points occurred in 37 of 366 (10%) ICD carriers [0.14/patient (95% confidence interval [CI] = 0.11-0.19)] versus 43 end points in 32 of 325 (10%) ICD carriers in 2019 [0.13/patient (95% CI = 0.10-0.18) P  = 0.75]. There was no difference between the distribution of any individual end point in 2020 versus 2019 although a nonsignificant mortality increase was observed (from 2.8% to 4.6%, P  = 0.19). The lowest weekly event rate occurred during the national lock down in spring 2020 but a similar trend occurred also in 2019 suggesting that the effect may not be linked to social distancing measures. CONCLUSIONS: We did not observe an increase in a combined end point including arrhythmic events and mortality in ICD carriers who were remotely monitored in 2020, compared to 2019, despite the negative impact of the coronavirus disease 2019 outbreak on the healthcare system.

Added Value of CCTA-Derived Features to Predict MACEs in Stable Patients Undergoing Coronary Computed Tomography.

Clinical evidence has emphasized the importance of coronary plaques' characteristics, rather than lumen stenosis, for the outcome of cardiovascular events. Coronary computed tomographic angiography (CCTA) has a well-established role as a non-invasive tool for assessing plaques. The aim of this study was to compare clinical characteristics and CCTA-derived information of stable patients with non-severe plaques in predicting major adverse cardiac events (MACEs) during follow-up. We retrospectively selected 371 patients (64% male) who underwent CCTA in our center from March 2016 to January 2021 with Coronary Artery Disease­Reporting and Data System (CAD-RADS) 0 to 3. Of those, 198 patients (53% male) had CAD-RADS 0 to 1. Among them, 183 (49%) had normal pericoronary fat attenuation index (pFAI), while 15 (60% male) had pFAI ≥ 70.1 Hounsfield unit (HU). The remaining 173 patients (76% male) had CAD-RADS 2 to 3 and were divided into patients with at least one low attenuation plaque (LAP) and patients without LAPs (n-LAP). Compared to n-LAP, patients with LAPs had higher pFAI (p = 0.005) and had more plaques than patients with n-LAP. Presence of LAPs was significantly higher in elderly (p < 0.001), males (p < 0.001) and patients with traditional risk factors (hypertension p = 0.0001, hyperlipemia p = 0.0003, smoking p = 0.0003, diabetes p = <0.0001, familiarity p = 0.0007). Among patients with CAD-RADS 0 to 1, the ones with pFAI ≥ 70.1 HU were more often hyperlipidemic (p = 0.05) and smokers (p = 0.007). Follow-up (25,4 months, range: 17.6−39.2 months) demonstrated that LAP and pFAI ≥ 70.1 significantly and independently (p = 0.04) predisposed to outcomes (overall mortality and interventional procedures). There is an added value of CCTA-derived features in stratifying cardiovascular risk in low- to intermediate-risk patients with non-severe, non-calcified coronary plaques. This is of utmost clinical relevance as it is possible to identify a subset of patients with increased risk who need strengthening in therapeutic management and closer follow-up even in the absence of severe CAD. Further studies are needed to evaluate the effect of medical treatments on pericoronary inflammation and plaque composition.

Clinical profile and long-term follow-up of a cohort of patients with desmoplakin cardiomyopathy.

BACKGROUND: Desmoplakin (DSP) genetic variants have been reported in arrhythmogenic cardiomyopathy with particular regard to predominant left ventricular (LV) involvement. OBJECTIVE: The purpose of this study was to improve our understanding of clinical phenotype and outcome of DSP variant carriers. METHODS: The clinical picture and outcome of 73 patients (36% probands) harboring a pathogenic/likely pathogenic DSP variant were evaluated. RESULTS: The phenotype during follow-up (mean 11 years; range 1-39 years) changed in 25 patients (35%), arrhythmogenic LV cardiomyopathy (ALVC) forms being the most frequent (n = 26 [36%]), followed by biventricular (BIV; n = 20 [27%]) and arrhythmogenic right ventricular cardiomyopathy (ARVC; n = 16 [22%]) forms. Major ventricular arrhythmias were detected in 21 patients (29%), and they were more common in ARVC (n = 6, 56%) and BIV forms (n = 8, 40%) than in ALVC forms (n = 4, 15%). In patients with ALVC, major ventricular arrhythmias occurred in the setting of a normal/mildly reduced systolic function. Heart failure (HF) occurred in 6 patients (8%); none affected with ALVC. Females showed more commonly LV involvement, while ARVC forms were more frequently detected in males (21 [61%] vs 15 [38%]; P = .147). Males showed a higher incidence of major ventricular arrhythmias (18 [52%] vs 9 [24%]; P = .036), HF (11 [31%] vs 1 [3%]; P = .004), and cardiac death (11 [31%] vs 0 [0%]; P < .001). CONCLUSION: The clinical phenotype in pathogenic/likely pathogenic DSP variant carriers is wide. Although most patients show LV involvement, 16 (22%) has right ventricular abnormalities in keeping with a "classical" arrhythmogenic cardiomyopathy form. In ALVC, HF and major ventricular arrhythmias seem less common than in right ventricular and BIV variants. Females show more frequently LV involvement and a better outcome.

Thyroid dysfunction on the heart: clinical effects, prognostic impact and management strategies.

Thyroid hormones have a considerable influence on cardiac function and structure. There are direct and indirect effects of thyroid hormone on the cardiovascular system, which are prominent in both hypothyroidism and hyperthyroidism. In this review, we discuss how thyroid dysfunction impacts cardiovascular pathophysiology and the underlying molecular mechanisms.

Prognostic Role of Myocardial Edema as Evidenced by Early Cardiac Magnetic Resonance in Survivors of Out-of-Hospital Cardiac Arrest: A Multicenter Study.

Background Sudden cardiac arrest (SCA) may be caused by an acute and reversible myocardial injury, a chronic and irreversible myocardial damage, or a primary ventricular arrhythmia. Cardiac magnetic resonance imaging may identify myocardial edema (ME), which denotes acute and reversible myocardial damage. We evaluated the arrhythmic outcome of SCA survivors during follow-up and tested the prognostic role of ME. Methods and Results We included a consecutive series of 101 (71% men, median age 47 years) SCA survivors from 9 collaborative centers who underwent early (<1 month) cardiac magnetic resonance imaging and received an implantable cardioverter-defibrillator (ICD). On T2-weighted sequences, ME was found in 18 of 101 (18%) patients. According to cardiac magnetic resonance imaging findings, the arrhythmic SCA was ascribed to acute myocardial injury (either ischemic [n=10] or inflammatory [n=8]), to chronic structural heart diseases (ischemic heart disease [n=11], cardiomyopathy [n=20], or other [n=23]), or to primarily arrhythmic syndrome (n=29). During a follow-up of 47 months (28 to 67 months), 24 of 101 (24%) patients received an appropriate ICD intervention. ME was associated with a significantly higher survival free from both any ICD interventions (log-rank=0.04) and ICD shocks (log-rank=0.03) and remained an independent predictor of better arrhythmic outcome after adjustment for left ventricular ejection fraction and late gadolinium enhancement. The risk of appropriate ICD intervention was unrelated to the type of underlying heart disease. Conclusions ME on early cardiac magnetic resonance imaging, which denotes an acute and transient arrhythmogenic substrate, predicted a favorable long-term arrhythmic outcome of SCA survivors. These findings may have a substantial impact on future guidelines on the management of SCA survivors.

Arrhythmogenic Cardiomyopathy-Current Treatment and Future Options.

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.

Arrhythmogenic Left Ventricular Cardiomyopathy: Genotype-Phenotype Correlations and New Diagnostic Criteria.

Arrhythmogenic cardiomyopathy (ACM) is an inherited heart muscle disease characterized by loss of ventricular myocardium and fibrofatty replacement, which predisposes to scar-related ventricular arrhythmias and sudden cardiac death, particularly in the young and athletes. Although in its original description the disease was characterized by an exclusive or at least predominant right ventricle (RV) involvement, it has been demonstrated that the fibrofatty scar can also localize in the left ventricle (LV), with the LV lesion that can equalize or even overcome that of the RV. While the right-dominant form is typically associated with mutations in genes encoding for desmosomal proteins, other (non-desmosomal) mutations have been showed to cause the biventricular and left-dominant variants. This has led to a critical evaluation of the 2010 International Task Force criteria, which exclusively addressed the right phenotypic manifestations of ACM. An International Expert consensus document has been recently developed to provide upgraded criteria ("the Padua Criteria") for the diagnosis of the whole spectrum of ACM phenotypes, particularly left-dominant forms, highlighting the use of cardiac magnetic resonance. This review aims to offer an overview of the current knowledge on the genetic basis, the phenotypic expressions, and the diagnosis of left-sided variants, both biventricular and left-dominant, of ACM.

Coronary artery calcium on standard chest computed tomography predicts cardiovascular events after liver transplantation.

AIMS: Cardiac complications are a leading cause of mortality after orthotopic liver transplantation (LT) and pre-operative risk stratification is challenging. We evaluated whether coronary artery calcium (CAC) score calculated on a standard (non-thin layer, non-ECG gated) chest computed tomography (CT) predicted cardiac outcome after LT. METHODS: We included a consecutive series of LT recipients who underwent pre-operative cardiac evaluation including stress-testing or cardiac catheterization in high-risk patients. Patients with a history of coronary artery disease or coronary revascularization were excluded. The CAC score was calculated from the chest CT routinely performed before LT. CAC values were not available at the time of pre-transplant cardiac evaluation and did not affect LT eligibility. The primary end-point included peri-operative arrhythmic cardiac arrest and sustained ventricular arrhythmias; heart failure, myocardial infarction and cardiac death within 1-year after LT. RESULTS: The study population consisted of 301 patients (median age 56 years, 76% males). At chest CT, 49% had CAC = 0; 27% had CAC = 1-99, 15% had CAC = 100-399 and 9% CAC > 400. The primary end-point incidence increased from 7% in patients with CAC = 0 to 27% in patients with CAC > 400 (p = 0.007). At multivariable analysis including traditional risk factors, CAC remained an independent predictor of cardiac events (p = 0.01). CONCLUSIONS: CAC score calculated on a standard chest CT stratified the risk of cardiac events in patients who underwent LT after negative pre-transplant cardiac evaluation. These findings suggest that evaluation of CAC from a standard chest CT performed for other reasons can be used as an early cardiac risk stratification tool before LT.

Differential diagnosis of arrhythmogenic cardiomyopathy: phenocopies versus disease variants.

Arrhythmogenic cardiomyopathy (ACM) is a genetic heart muscle disease caused by mutations of desmosomal genes in about 50% of patients. Affected patients may have defective non-desmosomal genes. The ACM phenotype may occur in other genetic cardiomyopathies, cardio-cutaneous syndromes or neuromuscular disorders. A sizeable proportion of patients have non-genetic diseases with clinical features resembling ACM (phenocopies). The identification of biventricular and left-dominant phenotypic variants has made differential diagnosis more difficult because of the broader spectrum of phenocopies which requires a detailed clinical study with appropriate evaluation of most prominent and discriminatory disease features. Conditions that enter into differential diagnosis of ACM include heart muscle diseases affecting the right ventricle, the left ventricle, or both. To confirm a conclusive diagnosis of ACM, these differential possibilities need to be reasonably excluded by an accurate and targeted clinical evaluation. This article reviews the clinical and imaging features of major phenocopies of ACM and provides indications for differential diagnosis. The recent etiologic classification of Arrhythmogenic Cardiomyopathies, whose common denominator is the distinctive phenotype characterized by a hypokinetic and non-dilated ventricle with a large amount of myocardial fibrosis underlying its propensity to generate ventricular arrhythmias is also addressed.

Arrhythmogenic Cardiomyopathy and Sports Activity.

Arrhythmogenic right-ventricular cardiomyopathy (ARVC) is a genetically determined heart disease characterized by progressive myocyte death and substitution by fibrofatty tissue. Life-threatening ventricular arrhythmias may occur during the course of the disease and are distinctively triggered by sports activity: for this reason, ARVC is one of the leading causes of sudden death in the athlete. Early identification of affected athletes by preparticipation screening in the pre-symptomatic phase is essential, but differential diagnosis with the athlete's heart may be challenging. Variants with predominant involvement of the left ventricle are difficult to diagnose unless cardiac magnetic resonance is performed. Athletes with overt ARVC or asymptomatic carriers of pathological gene mutations, including those with an implantable cardioverter defibrillator, should refrain from competitive sports, while a moderate-intensity recreational physical activity appears safe.