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.

Vacuum-Implemented Removal of Lead Vegetations in Cardiac Device-Related Infective Endocarditis.

When approaching infected lead removal in cardiac device-related infective endocarditis (CDRIE), a surgical consideration for large (>20 mm) vegetations is recommended. We report our experience with the removal of large CDRIE vegetations using the AngioVac system, as an alternative to conventional surgery. We retrospectively reviewed all infected lead extractions performed with a prior debulking using the AngioVac system, between October 2016 and April 2022 at our institution. A total of 13 patients presented a mean of 2(1) infected leads after a mean of 5.7(5.7) years from implantation (seven implantable cardioverter-defibrillators, four cardiac resynchronization therapy-defibrillators, and two pacemakers). The AngioVac system was used as a venous−venous bypass in six cases (46.2%), venous−venous ECMO-like circuit (with an oxygenator) in five (38.5%), and venous−arterial ECMO-like circuit in two cases (15.4%). Successful (>70%) aspiration of the vegetations was achieved in 12 patients (92.3%) and an intraoperative complication (cardiac perforation) only occurred in 1 case (7.7%). Subsequent lead extraction was successful in all cases, either manually (38.5%) or using mechanical tools (61.5%). The AngioVac system is a promising effective and safe option for large vegetation debulking in CDRIE. Planning the extracorporeal circuit design may represent the optimal strategy to enhance the tolerability of the procedure and minimize adverse events.

Evolving Diagnostic Criteria for Arrhythmogenic Cardiomyopathy.

Criteria for diagnosis of arrhythmogenic cardiomyopathy (ACM) were first proposed in 1994 and revised in 2010 by a Task Force. Although the Task Force criteria demonstrated a good accuracy for diagnosis of the original right ventricular phenotype (arrhythmogenic right ventricular cardiomyopathy), they lacked sensitivity for identification of the expanding phenotypic spectrum of ACM, which includes left-sided variants and did not incorporate late-gadolinium enhancement findings by cardiac magnetic resonance. The 2020 International criteria ("Padua criteria") have been developed by International experts with the aim to improve the diagnosis of ACM by providing new criteria for the diagnosis of left ventricular phenotypic features. The key upgrade was the incorporation of tissue characterization findings by cardiac magnetic resonance for noninvasive detection of late-gadolinium enhancement/myocardial fibrosis that are determinants for characterization of arrhythmogenic biventricular and left ventricular cardiomyopathy. The 2020 International criteria are heavily dependent on cardiac magnetic resonance, which has become mandatory to characterize the ACM phenotype and to exclude other diagnoses. New criteria regarding left ventricular depolarization and repolarization ECG abnormalities and ventricular arrhythmias of left ventricular origin were also provided. This article reviews the evolving approach to diagnosis of ACM, going back to the 1994 and 2010 International Task Force criteria and then grapple with the modern 2020 International criteria.

Appropriate use criteria for cardiovascular magnetic resonance imaging (CMR): SIC-SIRM position paper part 1 (ischemic and congenital heart diseases, cardio-oncology, cardiac masses and heart transplant).

Cardiac magnetic resonance (CMR) has emerged as new mainstream technique for the evaluation of patients with cardiac diseases, providing unique information to support clinical decision-making. This document has been developed by a joined group of experts of the Italian Society of Cardiology and Italian society of Radiology and aims to produce an updated consensus statement about the current state of technology and clinical applications of CMR. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac radiology. Part 1 of the document will cover ischemic heart disease, congenital heart disease, cardio-oncology, cardiac masses and heart transplant.

The alcohol-induced cardiomyopathy: A cardiovascular magnetic resonance characterization.

BACKGROUND: Alcoholic cardiomyopathy(ACM) is part of the non-ischaemic dilated cardiomyopathy(NI-DCM) spectrum. Little is known about cardiovascular magnetic resonance(CMR) features in ACM patients. The aim of this study is to describe CMR findings and their prognostic impact in ACM patients. METHODS: Consecutive ACM patients evaluated in five referral CMR centres from January 2005 to December 2018 were enrolled. CMR findings and their prognostic value were compared to idiopathic NI-DCM(iNI-DCM) patients. The main outcome was a composite of death/heart transplantation/life-threatening arrhythmias. RESULTS: Overall 114 patients (52 with ACM and 62 with iNI-DCM) were included. ACM patients were more often males compared to iNI-DCM (90% vs 64%, respectively, p ≤ 0.001) and were characterized by a more pronounced biventricular adverse remodelling than iNI-DCM, i.e. lower LVEF (31 ± 12% vs 38 ± 11% respectively, p = 0.001) and larger left ventricular end-diastolic volume (116 ± 40 ml/m2 vs 67 ± 20 ml/m2 respectively, p < 0.001). Similarly to iNI-DCM, late gadolinium enhancement (LGE), mainly midwall, was present in more than 40% of ACM patients but, conversely, it was not associated with adverse outcome(p = 0.15). LGE localization was prevalently septal (87%) in ACM vs lateral in iNI-DCM(p < 0.05). Over a median follow-up of 42 months [Interquartile Range 24-68], adverse outcomes were similar in both groups(p = 0.67). CONCLUSIONS: ACM represents a specific phenotype of NI-DCM, with severe morpho-functional features at the onset, but similar long-term outcomes compared to iNI-DCM. Despite the presence and pattern of distribution of LGE was comparable, ACM and iNI-DCM showed a different LGE localization, mostly septal in ACM and lateral in iNI-DCM, with different prognostic impact.

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.

'Hot phase' clinical presentation in arrhythmogenic cardiomyopathy.

AIMS: The aim of this study is to evaluate the clinical features of patients affected by arrhythmogenic cardiomyopathy (AC), presenting with chest pain and myocardial enzyme release in the setting of normal coronary arteries ('hot phase'). METHODS AND RESULTS: We collected detailed anamnestic, clinical, instrumental, genetic, and histopathological findings as well as follow-up data in a series of AC patients who experienced a hot phase. A total of 23 subjects (12 males, mean age at the first episode 27 ± 16 years) were identified among 560 AC probands and family members (5%). At first episode, 10 patients (43%) already fulfilled AC diagnostic criteria. Twelve-lead electrocardiogram recorded during symptoms showed ST-segment elevation in 11 patients (48%). Endomyocardial biopsy was performed in 11 patients, 8 of them during the acute phase showing histologic evidence of virus-negative myocarditis in 88%. Cardiac magnetic resonance was performed in 21 patients, 12 of them during the acute phase; oedema and/or hyperaemia were detected in 7 (58%) and late gadolinium enhancement in 11 (92%). At the end of follow-up (mean 17 years, range 1-32), 12 additional patients achieved an AC diagnosis. Genetic testing was positive in 77% of cases and pathogenic mutations in desmoplakin gene were the most frequent. No patient complained of sustained ventricular arrhythmias or died suddenly during the 'hot phase'. CONCLUSION: 'Hot phase' represents an uncommon clinical presentation of AC, which often occurs in paediatric patients and carriers of desmoplakin gene mutations. Tissue characterization, family history, and genetic test represent fundamental diagnostic tools for differential diagnosis.

Axillary vein access for permanent pacemaker and implantable cardioverter defibrillator implantation: Fluoroscopy compared to ultrasound.

BACKGROUND: Axillary vein access (AVA) using fluoroscopic landmarks is an effective and safe approach for cardiac implantable electronic devices (CIEDs) implantation. However, it may result in a higher radiation exposure. Ultrasound-guided axillary access (USAA) is an effective alternative technique to conventional subclavian access for CIEDs implantation. Studies comparing USAA and AVA using fluoroscopic landmarks are lacking. The purpose of this study was to compare the safety, efficacy, and radiation exposure data of the USAA approach with the AVA using fluoroscopic landmarks. METHODS: The study population included 95 consecutive patients (61% male, median age 78 years [71-85 years]) referred for CIEDs implantation using AVA with fluoroscopic landmark (n = 46) or USAA (n = 49). Baseline characteristics and radiation exposure data (Air-Kerma [mGy], DAP [Gy-cm2 ], fluoroscopy time [seconds], and X-rays emission time [seconds]) were compared according to the technique used for the AVA. RESULTS: Axillary vein was successfully accessed in 45 of 49 (92%) patients using ultrasound and in 42 of 46 (91%) patients using fluoroscopic landmarks (P = 1.00). Air-Kerma, DAP, fluoroscopy time, and X-rays emission time were shorter for USAA group compared with AVA using fluoroscopic landmarks (11 mGy [8-20] vs 37 mGy [24-81], P < .00001; 3 Gy-cm2 [2-5] vs 10 Gy-cm2 [6-16], P < .00001; 97 seconds [62-163] vs 271 seconds [185-365], P < .00001; and 7 seconds [4-10] vs 21 seconds [13-39], P < .00001). There were no significant differences between the two groups in median implant procedure time (P = .55). We did not encounter any acute or long-term complications in both groups. CONCLUSIONS: Ultrasound-guided axillary vein cannulation for CIEDs implantation is a feasible and safe alternative approach and offers a significant reduction in fluoroscopy times without increasing procedural time.

Arrhythmogenic Right Ventricular Cardiomyopathy: Characterization of Left Ventricular Phenotype and Differential Diagnosis With Dilated Cardiomyopathy.

Background This study assessed the prevalence of left ventricular (LV) involvement and characterized the clinical, electrocardiographic, and imaging features of LV phenotype in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Differential diagnosis between ARVC-LV phenotype and dilated cardiomyopathy (DCM) was evaluated. Methods and Results The study population included 87 ARVC patients (median age 34 years) and 153 DCM patients (median age 51 years). All underwent cardiac magnetic resonance with quantitative tissue characterization. Fifty-eight ARVC patients (67%) had LV involvement, with both LV systolic dysfunction and LV late gadolinium enhancement (LGE) in 41/58 (71%) and LV-LGE in isolation in 17 (29%). Compared with DCM, the ARVC-LV phenotype was statistically significantly more often characterized by low QRS voltages in limb leads, T-wave inversion in the inferolateral leads and major ventricular arrhythmias. LV-LGE was found in all ARVC patients with LV systolic dysfunction and in 69/153 (45%) of DCM patients. Patients with ARVC and LV systolic dysfunction had a greater amount of LV-LGE (25% versus 13% of LV mass; P<0.01), mostly localized in the subepicardial LV wall layers. An LV-LGE ≥20% had a 100% specificity for diagnosis of ARVC-LV phenotype. An inverse correlation between LV ejection fraction and LV-LGE extent was found in the ARVC-LV phenotype (r=-0.63; P<0.01), but not in DCM (r=-0.01; P=0.94). Conclusions LV involvement in ARVC is common and characterized by clinical and cardiac magnetic resonance features which differ from those seen in DCM. The most distinctive feature of ARVC-LV phenotype is the large amount of LV-LGE/fibrosis, which impacts directly and negatively on the LV systolic function.

Incidence and pattern of conduction gaps after pulmonary vein isolation with the endoscopic ablation system.

PURPOSE: Durable pulmonary vein isolation (PVI) is the goal of atrial fibrillation (AF) ablation. The endoscopic ablation system (EAS) is associated with a high rate of persistent PVI. The aim of this study was to analyze the incidence and pattern of conduction gaps in patients with arrhythmia recurrence after an EAS-guided PVI. METHODS: Repeat ablations after an EAS-guided PVI were analyzed. After PV angiograms, PV reconnection was assessed. Radiofrequency ablation was delivered at the earliest pulmonary vein (PV) activation site (gap) with the goal of PV re-isolation. First, the incidence of reconnected PVs per patient was assessed. Second, the gap pattern according to the individual PV quadrant was analyzed. RESULTS: Fifty-nine out of 373 (16%) patients underwent a second procedure after index EAS. PV reconnection was observed in 71/230 (31%) PVs without statistically significant differences between individual PVs. A higher incidence of gaps was found for right PVs (49 vs. 27; p 0.0006). The carina between the superior and inferior PV presented a low incidence of gaps (18 vs. 56, p < 0.0001). Gaps were also predominant at the AS segment of the RSPV (11 gaps). No predictors of reconnection were found, except the higher total amount of application in the reconnected right inferior PV (26.03 ± 1.30 vs. 32.04 ± 2.89; p 0.0396). CONCLUSION: EAS-guided PVI results in a 72% durable PVI rate in patients with AF recurrences without difference between individual PVs. More of the gap was found in the right PVs especially in the anterosuperior segment of the RSPV.

Relationship Between Electrocardiographic Findings and Cardiac Magnetic Resonance Phenotypes in Arrhythmogenic Cardiomyopathy.

Background The new designation of arrhythmogenic cardiomyopathy defines a broader spectrum of disease phenotypes, which include right dominant, biventricular, and left dominant variants. We evaluated the relationship between electrocardiographic findings and contrast-enhanced cardiac magnetic resonance phenotypes in arrhythmogenic cardiomyopathy. Methods and Results We studied a consecutive cohort of patients with a definite diagnosis of arrhythmogenic cardiomyopathy, according to 2010 International Task Force criteria, who underwent electrocardiography and contrast-enhanced cardiac magnetic resonance. Both depolarization and repolarization electrocardiographic abnormalities were correlated with the severity of dilatation/dysfunction, either global or regional, of both ventricles and the presence and regional distribution of late gadolinium enhancement. The study population included 79 patients (60% men). There was a statistically significant relationship between the presence and extent of T-wave inversion across a 12-lead ECG and increasing values of median right ventricular ( RV ) end-diastolic volume ( P<0.001) and decreasing values of RV ejection fraction ( P<0.001). The extent of T-wave inversion to lateral leads predicted a more severe RV dilatation rather than a left ventricular involvement because of the leftward displacement of the dilated RV , as evidenced by contrast-enhanced cardiac magnetic resonance. A terminal activation delay of >55 ms in the right precordial leads (V1-V3) was associated with higher RV volume ( P=0.014) and lower RV ejection fraction ( P=0.053). Low QRS voltages in limb leads predicted the presence ( P=0.004) and amount ( P<0.001) of left ventricular late gadolinium enhancement. Conclusions The study results indicated that electrocardiographic abnormalities predict the arrhythmogenic cardiomyopathy phenotype in terms of severity of RV disease and left ventricular involvement, which are among the most important determinants of the disease outcome.

Clinical recommendations of cardiac magnetic resonance, Part II: inflammatory and congenital heart disease, cardiomyopathies and cardiac tumors: a position paper of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Society of Cardiology.

The current document was developed by the working group on the 'application of cardiac magnetic resonance' of the Italian Society of Cardiology to provide a perspective on the current state of technical advances and clinical cardiac magnetic resonance applications and to inform cardiologists how to implement their clinical and diagnostic pathway with the introduction of this technique in the clinical practice. Appropriateness criteria were defined using a score system: score 1-3 = inappropriate (test is not generally acceptable and is not a reasonable approach for the indication), score 4-6 = uncertain (test may be generally acceptable and may be a reasonable approach for the indication but more research and/or patient information is needed to classify the indication definitively) and score 7-9 = appropriate (test is generally acceptable and is a reasonable approach for the indication).

Morphofunctional Abnormalities of Mitral Annulus and Arrhythmic Mitral Valve Prolapse.

BACKGROUND: Arrhythmic mitral valve prolapse (MVP) is characterized by myxomatous leaflets and left ventricular (LV) fibrosis of papillary muscles and inferobasal wall. We searched for morphofunctional abnormalities of the mitral valve that could explain a regional mechanical myocardial stretch. METHODS AND RESULTS: Thirty-six (27 female patients; median age: 44 years) arrhythmic MVP patients with LV late gadolinium enhancement on cardiac magnetic resonance and no or trivial mitral regurgitation, and 16 (6 female patients; median age: 40 years) MVP patients without LV late gadolinium enhancement were investigated by morphofunctional cardiac magnetic resonance. Mitral annulus disjunction (median: 4.8 versus 1.8 mm; P<0.001), end-systolic mitral annular diameters (median: 41.2 versus 31.5; P=0.004) and end-diastolic mitral annular diameters (median: 35.5 versus 31.5; P=0.042), prevalence of posterior systolic curling (34 [94%] versus 3 [19%]; P<0.001), and basal to mid LV wall thickness ratio >1.5 (22 [61%] versus 4 [25%]; P=0.016) were higher in MVP patients with late gadolinium enhancement than in those without. A linear correlation was found between mitral annulus disjunction and curling (R=0.85). A higher prevalence of auscultatory midsystolic click (26 [72%] versus 6 [38%]; P=0.018) was also noted. Histology of the mitral annulus showed a longer mitral annulus disjunction in 50 sudden death patients with MVP and LV fibrosis than in 20 patients without MVP (median: 3 versus 1.5 mm; P<0.001). CONCLUSIONS: Mitral annulus disjunction is a constant feature of arrhythmic MVP with LV fibrosis. The excessive mobility of the leaflets caused by posterior systolic curling accounts for a mechanical stretch of the inferobasal wall and papillary muscles, eventually leading to myocardial hypertrophy and scarring. These mitral annulus abnormalities, together with auscultatory midsystolic click, may identify MVP patients who would need arrhythmic risk stratification.

Nonischemic Left Ventricular Scar as a Substrate of Life-Threatening Ventricular Arrhythmias and Sudden Cardiac Death in Competitive Athletes.

BACKGROUND: The clinical profile and arrhythmic outcome of competitive athletes with isolated nonischemic left ventricular (LV) scar as evidenced by contrast-enhanced cardiac magnetic resonance remain to be elucidated. METHODS AND RESULTS: We compared 35 athletes (80% men, age: 14-48 years) with ventricular arrhythmias and isolated LV subepicardial/midmyocardial late gadolinium enhancement (LGE) on contrast-enhanced cardiac magnetic resonance (group A) with 38 athletes with ventricular arrhythmias and no LGE (group B) and 40 healthy control athletes (group C). A stria LGE pattern with subepicardial/midmyocardial distribution, mostly involving the lateral LV wall, was found in 27 (77%) of group A versus 0 controls (group C; P<0.001), whereas a spotty pattern of LGE localized at the junction of the right ventricle to the septum was respectively observed in 11 (31%) versus 10 (25%; P=0.52). All athletes with stria pattern showed ventricular arrhythmias with a predominant right bundle branch block morphology, 13 of 27 (48%) showed ECG repolarization abnormalities, and 5 of 27 (19%) showed echocardiographic hypokinesis of the lateral LV wall. The majority of athletes with no or spotty LGE pattern had ventricular arrhythmias with a predominant left bundle branch block morphology and no ECG or echocardiographic abnormalities. During a follow-up of 38±25 months, 6 of 27 (22%) athletes with stria pattern experienced malignant arrhythmic events such as appropriate implantable cardiac defibrillator shock (n=4), sustained ventricular tachycardia (n=1), or sudden death (n=1), compared with none of athletes with no or LGE spotty pattern and controls. CONCLUSIONS: Isolated nonischemic LV LGE with a stria pattern may be associated with life-threatening arrhythmias and sudden death in the athlete. Because of its subepicardial/midmyocardial location, LV scar is often not detected by echocardiography.