Epsilon Waves Research Articles

Navigating the Uncommon: Case Report of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Successfully Managed with Implantable Cardioverter Defibrillator (ICD)

With a high risk of sudden cardiac mortality, arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited cardiomyopathy characterized by right ventricular dysfunction and ventricular arrhythmias (VA). In this case study, a 35-year-old presented with palpitations and revealed epsilon waves on the right precordial electrocardiogram (ECG) leads which led to the suspicion of ARVC. A 24-hour Holter monitoring revealed frequent ventricular extrasystoles (>500 per 24 hours), a CMRI revealed RV dyskinesia and transmural LGE in the apical RV, and an electrophysiologic study detected spontaneous polymorphic ventricular tachycardia (VT) despite the presence of induction ventricle fibrillation (VF). These results validated the diagnosis of ARVC and indicated that an implantable cardioverter defibrillator was necessary treatment. The ability to identify potential ARVC’s ECG abnormalities, the timing to pursue further studies, and determining necessary treatment execution are critical. The evaluation of cardiac, electrophysiological, and clinical imaging parameters is essential for the risk stratification, diagnosis, and management of patients with ARVC.

Electrocardiographic correlates of ventricular arrhythmias in repaired congenital heart disease

BackgroundSudden cardiac death (SCD) is a major cause of mortality in congenital heart disease (CHD). Ventricular arrhythmias (VAs) are responsible for 80% of SCD. However, the clinical characteristics of patients with CHD and VAs are not fully understood. ObjectiveThis study was undertaken to evaluate clinical and electrocardiographic characteristics of patients with CHD based on the presence or absence of VAs. MethodsWe identified 28 patients with CHD with VAs (men, n = 15; 35.9 ± 16.5 years). Two patients with channelopathies were excluded from the analysis. ResultsThe most common diagnoses in patients with VAs were a transposition of the great arteries (n = 8, 30.8%), followed by tetralogy of Fallot (n = 7, 26.9%). Compared with patients without VA (n = 43), those with VAs had a longer QRS (160.6 ± 52.9 ms vs 133.4 ± 29.3 ms; P = .004), a higher prevalence of fragmented QRS (65.4% vs 37.2%; P = .022) and more epsilon wave (23.1% vs 2.3%; P = .005). Multivariable analysis showed that QRS > 180 ms (odds ratio [OR], 22.23; 95% confidence interval [CI], 2.40–206.53) and epsilon wave (OR, 14.33; 95% CI, 1.47–139.58) were significantly associated with VAs. During a median follow-up duration of 5.4 years, 5 patients (19.2%) received appropriate ICD therapy, and 3 patients (11.5%) died of heart failure. ConclusionThe assessment of QRS duration and the presence of fQRS and epsilon waves in patients with CHD could improve risk prediction for the development of VAs. These electrocardiogram (ECG) features could assist in clinical decision-making and might consequently reduce mortality.

Correlation between Epsilon Wave and Late Potentials in Arrhythmogenic Right Ventricular Cardiomyopathy-Do Late Potentials Define the Epsilon Wave?

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterised by progressive fibrosis predominantly of the right ventricular (RV) myocardium, resulting in life-threatening arrhythmias and heart failure. The diagnosis is challenging due to a wide spectrum of clinical symptoms. The important role of ECG was covered in the current diagnostic criteria. The role of the epsilon wave (EW) is still under discussion. Aim: The aim of the study was to examine a potential association between the EW and late ventricular potentials (LPs) in ARVC patients (pts). The correlation between RV dilatation or dysfunction and LPs/EW was also analysed. Methods: The ARVC group consisted of 81 pts (53 men, aged 20-78 years) fulfilling 2010 International Task Force Criteria. 12-lead ECG, LPs, Holter, and ECHO were performed in all pts. The presence of EW was analysed in ECG by 3 investigators. LPs were detected by signal-averaged ECG (SAECG). SAECG was considered positive for LPs when at least two of the three following criteria were met: (1) the filtered QRS duration (fQRS) ≥ 114 msec; (2) the duration of the final QRS fragment in which low-amplitude signals lower than 40 μV are recorded (LAS-40 > 38 msec); and (3) the root mean square amplitude of the last 40 milliseconds of the fQRS complex (RMS-40 < 20 μV). The results were compared with a reference group consisting of 53 patients with RV damage in the course of atrial septum defect (ASD) or Ebstein's Anomaly (EA). Results: In the ARVC group, a significant relationship was observed between the occurrence of EW and the presence of LPs. EW was more common in the LP+ than in the LP- patients (48.1% vs. 6.9%, p < 0001; OR 12.5; 95% CI [2.691-58.063]). In ARVC pts, RVOT > 36 mm, RVIT > 41 mm, and RV S' < 9 cm/s were observed significantly more often in the LPs+ than in the LPs- group (OR [95% CI]: 8.3 [2.9-1.5], 6.4 [2.2-19.0] and 3.6 [1.1-12.2], respectively). In the ARVC group, any of fQRS > 114 ms, LAS > 38 ms, and RMS < 20 μV were significantly more frequent in EW+ pts. In multivariate analysis, the independent factors of the EW were LAS-40 and RV S'. In the LPs- subgroup, RVOT > 36 mm was more frequent in ASD/EA than in ARVC (70.4% vs. 25%, p = 0.002). Similarly, in the LPs- subgroup, RVIT > 41 mm was encountered more frequently in ASD/EA than in ARVC (85.2% vs. 48.3%, p = 0.004). Conclusions: In ARVC, there is an association between EW and LPs, with both probably resulting from the same process of fibrofatty substitution of the RV myocardium. Although RV dilatation is common in ASD and EA, it does not correlate with LPs.

Ventricular Angiography: A Forgotten Diagnostic Tool?

A 76-year-old male patient presented to the emergency room with acute decompensated right heart failure and presyncope episodes. Upon admission, his electrocardiogram (ECG) showed sustained monomorphic ventricular tachycardia at 180 bpm, which was electrically cardioverted, and the patient was subsequently admitted to the intensive care unit. The echocardiography showed a very dilated right ventricle (RV) with global systolic dysfunction and akinetic anterior and lateral walls. The coronary angiography was normal. The cardiac magnetic resonance showed signs of fibro-fatty replacement of the RV myocardium. Furthermore, the ECG after cardioversion showed inverted T waves and an epsilon wave in V1-V3 leads and late potentials by signal-averaged ECG. As such, a diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) was suspected. However, he presented no familial history of ARVC, was 76 years of age at the time of diagnosis and was asymptomatic until now. Given these considerations, we performed a right ventricular angiography which showed dilatation of the RV with akinetic/dyskinetic bulging, creating the "pile d'assiettes" image suggestive of ARVC. In the case of this patient, the RV angiography contributed to establish a diagnosis of ARVC with a very late presentation, to our knowledge the latest presentation in terms of age described in the literature.

Arrhythmogenic right ventricular cardiomyopathy with sustained ventricular tachycardia: a case report

IntroductionArrhythmogenic right ventricular cardiomyopathy (ARVC) is an infrequent hereditary disorder distinguished by fibrofatty replacement of the myocardium in the right ventricular, which predisposes individuals to life-threatening arrhythmias. This case delineates an ARVC patient who suffered recurrent bouts of sustained ventricular tachycardia (VT). In this case, we mainly discuss the application of myocardial contrast echocardiography (MCE) in displaying myocardial fibrosis in patients with ARVC.Case presentationA 43-year-old male experienced three episodes of unexplained VT over an eight-year period, accompanied by symptoms of chest discomfort, palpitations and dizziness. Coronary angiography revealed no significant coronary stenosis. The electrocardiogram (ECG) results indicated characteristic epsilon waves in right precordial leads, and subsequent echocardiography identified right ventricular enlargement and right ventricular systolic dysfunction. MCE further disclosed regional myocardial ischemia at the epicardium of the left ventricular apex. Ultimately, cardiovascular magnetic resonance imaging (CMR) corroborated the ARVC diagnosis, highlighting linear intensification in the right ventricle during the delayed enhancement.ConclusionPrompt identification of ARVC is crucial for timely intervention and management. MCE may offer an effective and valuable technique for the detection of myocardial involvement in ARVC patient.

A Novel Presentation: Epsilon Waves in the Electrocardiogram of a Patient with Dravet Syndrome Without Structural Heart Disease

We document for the first time epsilon waves on the electrocardiogram of a patient with Dravet syndrome (DS) who does not exhibit structural cardiac pathology. DS, a severe form of pediatric epilepsy, involves mutations in the SCN1A gene, which disrupt sodium ion flow and increase the risk of sudden unexpected death in epilepsy. The epsilon waves, typically associated with arrhythmogenic right ventricular dysplasia, may also suggest a link between neuronal and cardiac dysfunctions. In our case, the epsilon waves appear to originate from abnormalities in sodium channels rather than structural changes in the myocardium. This finding underscores the importance of assessing both neurological and cardiac manifestations in patients with severe epilepsy, opening new avenues for the research and treatment of these interactions in DS.

ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY AND CARDIAC SARCOIDOSIS: THE GREY ZONE

Abstract Cardiac sarcoidosis (CS) is a rare multisystem disorder characterized by granulomatous infiltration of the myocardium, whose clinical manifestations can be extremely heterogeneus. We report the case of a 47–year–old man with a previous diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVD). In history he had a marked arrhythmic pattern with multiple episodes of sustained ventricular arrhythmias, biventricular disfunction (LVEF 37%, RVEF 32%) and extensive biventricular transmural late–gadolinium enhancement (greater than 50%) at cardiac RMN. At EKG epsilon wave mainly seen in precordial leads. In November 2022 he was implanted with bicameral defibrillator and in March 2023 he underwent ablation procedure for ventricular tachycardia with RF with endo–epicardial approach. In May 2023 he arrived at our Centre for acute decompensated heart failure. At restored hemodynamic stability, screening for the possible inclusion in transplant list was started. Right heart catheterization (RHC) showed low cardiac index with no pulmonary hypertension. Chest CT unexpectedly showed the presence of multiple micronodules with perilymphatic distribution with confluent appearance compatible with pulmonary sarcoidosis. In consideration of this result, the transplant program was temporarily postponed and investigations for possible cardiac involvement of an inflammatory nature were started. 18F–FDG PET–CT showed pulmonary, splenic, lymphonodal and especially cardiac uptake in the mid–distal segment of the lateral wall of the left ventricle and in the inferior–apical site suspicious for inflammatory pathology. Unfortunately, both lymphonodal and cardiac biopsies were inconclusive because of insufficient material. Nevertheless, the clinical scenario satisfied the Japanese criteria for possible CS; therefore, treatment with prednisone 1 mg/kg was started and a 18F–FDG PET–CT was planned after 3 months of steroid therapy. CS can disguise as a phenocopy of arrhythmogenic right ventricular cardiomyopathy because of several common characteristics, especially arrhythmic presentation. Due to these similarities, a careful overall evaluation of each patient with ARVD is mandatory as several transplant centers have reported cases of CS in explanted heart with a pretransplant misdiagnosis of ARVD or dilated cardiomiopathy. Performing a chest CT in all ARVD patients as part of transplant screening may be considered.

Electrocardiographic Variants of Ventricular Predominance in Arrhythmogenic Cardiomyopathy

Desmoglein-2 and Desmocollin-2 mutations cause different types of arrhythmogenic cardiomyopathy either dominant right, biventricular or dominant left forms. These two mutations present with myocardial cell necrosis and calcification [1,2]. Signs of electrocardiographic right ventricular hypertrophy can be found in more than 50% [3] besides typical ECG criteria of arrhythmogenic cardiomyopathy like right precordial epsilon waves and T-wave inversions [4], QRS fragmentation [5], localized right precordial QRS prolongation [6], terminal activation delay [7], and large Q-waves, small R-waves and T-wave inversion in lead aVR [8].

Case report on Arrhythmogenic Right Ventricular Dysplasia

Arrhythmogenic cardiomyopathy (AC) is a genetic disease characterized by fibro-fatty replacement of either ventricles in isolation or in combination. It may cause tachyarrhythmias to sudden cardiac death, especially in young adult. When ventricular tachycardia (VT) is the principal manifestation then the condition is termed as arrhythmogenic right ventricular dysplasia (ARVD). Here we present a case of ARVD in a 36 years old hypertensive male who presented with sudden onset of chest tightness, palpitations, breathing difficulty, dizziness for 20 minutes. In emergency department his electrocardiogram (ECG) showed sustained VT. After 200 joule DC cardioversion he was reverted to sinus rhythm, then resting ECG showed T-wave inversion (TWI) in V1-V3 along with epsilon wave. His echocardiogram also revealed dilated right ventricle (RV) along with hypertrabeculation, RV wall motion abnormality and low RV ejection fraction (EF), his coronaries were normal on coronary angiogram (CAG). He was discharged from the hospital after Implantable Cardioverter Defibrilator (ICD) implantation with beta-blocker and advised to restrict excessive physical activity. J Bangladesh Coll Phys Surg 2024; 42: 86-91

Arrhythmogenic Right Ventricular Dysplasia Presenting with Sustained Ventricular Tachycardia: A Case Report

Arrhythmogenic right ventricular dysplasia (ARVD) is a cardiomyopathy characterized pathologically by fibrofatty tissue replacement of the myocyte of the right ventricle (RV) and clinically by life-threatening ventricular arrhythmias in young people. It is a major cause of sudden death. We present the case of a 60-year-old man with cardiovascular risk factors, was admitted for unstable ventricular tachycardia (VT) treated immediately with synchronized cardioversion. After the stabilization of the patient, Electrocardiogram demonstrated an epsilon wave in precordial leads and diffuse T-wave inversions. Transthoracic echocardiography revealed a dilated, hypokinetic right ventricle with moderately reduced function and a focal area of dyskinesia. The diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) was made and an implantable cardioverter defibrillator (ICD) was indicated for secondary prevention. This case report will present the clinical presentation, diagnosis and management of this rare disease.

Significant delayed conduction and characteristic ventricular tachycardias in patients with cardiac sarcoidosis and electrical storm.

Electrical storm (ES) of ventricular tachyarrhythmias (VTAs) is an important cause of sudden death in patients with cardiac sarcoidosis (CS). VTAs in CS are associated with myocardial scarring and inflammation. However, little is known about the risk factors of ES in patients with CS and VTAs. The objective of this study is to clarify the characteristics and risk factors for the development of ES in patients with CS. The study population included consecutive 52 patients with CS and sustained VTA. Twenty-five out of 52 patients experienced ES. We evaluated clinical characteristics, imaging modalities, and electrocardiogram (ECG) parameters to determine the risk factors associated with ES. Half of the patients experienced VTAs as the initial symptom of sarcoidosis, and eight patients had ES as the initial VTA episode. There were no differences in cardiac imaging abnormalities between patients with and without ES. Among ECG markers, significant QRS fragmentation (odds ratio [OR]: 7.9, p = .01) and epsilon waves (OR: 12.24, p = .02) were associated with ES. Among the ventricular tachycardia (VT) characteristics, multiple morphologies of monomorphic VTs (OR: 10.9, p < .01), short VT cycle lengths (OR: 12.5, p < .01), and polymorphic VT (OR: 13.5, p < .01) were associated with ES. Bidirectional VTs were detected in 10 patients with ES and one patient without ES. Immunosuppressive therapy relieved ES in some patients. ES was common in patients with CS and VTAs. Significant depolarization abnormalities that appeared as QRS fragmentation, epsilon waves, and specific VT characteristics were associated with ES.

Correlation between epsilon wave and late potentials in arrythmogenic right ventricular cardiomyopathy. Do late potentials define the epsilon wave?

Abstract Introduction Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterised by progressive fibrosis predominantly of the right ventricular (RV) myocardium resulting in life-threatening arrhythmias and heart failure. The diagnosis is challenging due to a wide spectrum of clinical symptoms. The important role of ECG was covered in the current diagnostic criteria. The role of epsilon wave (EW) is still under discussion. Aim The aim of the study was to correlate the presence of EW with late ventricular potentials (LPs) in ARVC patients (pts). The correlation between RV dilatation /dysfunction and LPs/EW was also analysed. Methods The ARVC group consisted of 81 pts (53 men, aged 20-78 years) fulfilling 2010 International Task Force Criteria. 12-lead ECG, LPs, Holter, ECHO were performed in all pts. The presence of EW, defined as low-amplitude deflection observed between the end of the QRS complex and the onset of the T wave was analysed in ECG by 3 investigators. LPs were defined as low-amplitude, high-frequency waveforms at the end of the QRS complex on signal-averaged ECG (SAECG). SAECG was considered positive for LPs when at least two of the three following criteria were met: filtered QRS duration (fQRS) &amp;gt;114 ms, root-mean-square voltage in the terminal 40 ms (RMS 40) &amp;lt;20 uV, or low amplitude (&amp;lt;40 µV) signal (LAS 40) duration &amp;gt;38 ms. The results were compared with a reference group consisting of 53 pts with RV damage in the course of atrial septum defect (ASD) (29 pts, 8 men, aged 22-80 years) or Ebstein Anomaly (EA) (24 pts, 11 men, aged 23-55 years). Results In the ARVC group, a significant relationship was observed between the occurrence of EW and the presence of LPs. EW was more common in LP+ than in LP- patients (48.1% vs 6.9%, p&amp;lt;0001; OR 12.5). In ARVC a relationship was also found between the presence of LPs and increased RV inflow tract (RVIT) and RV outflow tract (RVOT) dimensions, as well as a reduced RV S' wave value. RVOT &amp;gt;36 mm, RVIT &amp;gt;41 mm and RV S’ &amp;lt;9 cm/s were observed significantly more often in the LPs+ than in LPs- group (OR: 8.3, 6.4 and 3.6, respectively). In the ARVC group, any of fQRS &amp;gt;114 ms, LAS &amp;gt;38 ms, and RMS &amp;lt;20 uV were significantly more frequent in EW+ pts. In multivariate analysis, the only independent factor of the EW was fQRS (OR: 1.043 [1.020-1.067], p&amp;lt;0.001; AUC: 0.852). In the LPs- subgroup, RVOT &amp;gt;36 mm was more frequent in ASD/EA than in ARVC (70.4% vs 25%, p=0.002). Similarly, in the LPs- subgroup, RVIT &amp;gt;41 mm was encountered more frequently in ASD/EA than in ARVC (85.2% vs 48.3%, p=0.004). Conclusions In ARVC, there is an association between EW and LPs, with both probably resulting from the same process of fibrofatty substitution of the RV myocardium. Although RV dilatation is common in ASD and EA, it does not correlate with LPs, possibly due to a lower degree of fibrosis in ASD/EA compared to ARVC.

The Heart Has its Reasons Which Reason Knows Not: A Curious Case of Chest Pain

BackgroundElectrocardiographic (ECG) findings of T-wave inversions in V1–V3, with or without accompanying epsilon waves, often raise concerns for the rare, but potentially lethal, arrhythmogenic right ventricular cardiomyopathy (ARVC). However, this pattern may be found in pericardial agenesis, an even rarer pathology. Concomitant myocarditis can confuse this presentation further. Case ReportWe report a case of a previously healthy man who presented with left-sided chest pain, ECG findings suggestive of ARVC, and a final diagnosis of myocarditis with underlying partial pericardial agenesis. Why Should an Emergency Physician Be Aware of This?A growing number of cases have reported pericardial agenesis demonstrating ECG changes similar to ARVC. We discuss an approach to a diagnostically challenging patient. This case emphasizes the importance of a broad differential and the danger of premature closure.

The pivotal role of ECG in cardiomyopathies.

Cardiomyopathies are a heterogeneous group of pathologies characterized by structural and functional alterations of the heart. Recent technological advances in cardiovascular imaging offer an opportunity for deep phenotypic and etiological definition. Electrocardiogram (ECG) is the first-line diagnostic tool in the evaluation of both asymptomatic and symptomatic individuals. Some electrocardiographic signs are pathognomonic or fall within validated diagnostic criteria of individual cardiomyopathy such as the inverted T waves in right precordial leads (V1-V3) or beyond in individuals with complete pubertal development in the absence of complete right bundle branch block for the diagnosis of arrhythmogenic cardiomyopathy of the right ventricle (ARVC) or the presence of low voltages typically seen in more than 60% of patients with amyloidosis. Most other electrocardiographic findings such as the presence of depolarization changes including QRS fragmentation, the presence of epsilon wave, the presence of reduced or increased voltages as well as alterations in the repolarization phase including the negative T waves in the lateral leads, or the profound inversion of the T waves or downsloping of the ST tract are more non-specific signs which can however raise the clinical suspicion of cardiomyopathy in order to initiate a diagnostic procedure especially using imaging techniques for diagnostic confirmation. Such electrocardiographic alterations not only have a counterpart in imaging investigations such as evidence of late gadolinium enhancement on magnetic resonance imaging, but may also have an important prognostic value once a definite diagnosis has been made. In addition, the presence of electrical stimulus conduction disturbances or advanced atrioventricular blocks that can be seen especially in conditions such as cardiac amyloidosis or sarcoidosis, or the presence of left bundle branch block or posterior fascicular block in dilated or arrhythmogenic left ventricular cardiomyopathies are recognized as a possible expression of advanced pathology. Similarly, the presence of ventricular arrhythmias with typical patterns such as non-sustained or sustained ventricular tachycardia of LBBB morphology in ARVC or non-sustained or sustained ventricular tachycardia with an RBBB morphology (excluding the "fascicular pattern") in arrhythmogenic left ventricle cardiomyopathy could have a significant impact on the course of each disease. It is therefore clear that a learned and careful interpretation of ECG features can raise suspicion of the presence of a cardiomyopathy, identify diagnostic "red flags" useful for orienting the diagnosis toward specific forms, and provide useful tools for risk stratification. The purpose of this review is to emphasize the important role of the ECG in the diagnostic workup, describing the main ECG findings of different cardiomyopathies.

Characterization of right ventricular low voltage areas in patients with arrhythmogenic right ventricular cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by fibrofatty replacement in the myocardium progressing from the epicardium towards the endocardium and affecting primarily the right ventricle (RV). Little data is available on the distribution of RV electrical abnormalities at the era of epicardial and high-resolution mapping. Purpose To evaluate the extent and distribution of RV epicardial and endocardial low voltage areas and their relationship with ECG abnormalities in ARVC patients. Methods Patients with a definite ARVC diagnosis according to the 2020 Task Force Criteria, who underwent ventricular tachycardia ablation between 2016 and 2022 with a high-density RV 3-dimensional electroanatomic mapping, were included. A custom RV segmentation dividing the RV into 10 segments from endocardial maps was used: anterior and lateral right ventricular outflow tract (RVOT); basal and mid inferior wall; apex; septum; basal anterolateral, basal inferolateral, mid anterolateral and mid inferolateral RV free wall (Figure). A standard definition of electrical scar was used (bipolar voltage ≤0.5 mV), and scar areas were manually delineated. Percentage of scar was defined by the ratio between scar area and the total segment area. ECG abnormal findings, such as epsilon wave and T-wave inversion in precordial leads, were measured before ablation procedure. Results Twenty-nine consecutive definite ARVC patients were included, among whose 24 had epicardial mapping in addition to endocardial mapping. When considering all segments, the epicardial scar (median:70%, interquartile range [IQR] 37-97%) was larger (p&amp;lt;0.0001) than the endocardial scar (9% [IQR] 0-32%). The higher percentage of epicardial scar was found in the basal inferolateral (100% [IQR] 73-100%), basal anterolateral (94% [IQR] 67-100%), RV free wall and lateral RVOT (89% [IQR] 48-100%) segments (Table). Transmural scar was observed mostly in basal inferolateral RV free wall (10 patients, 41%) and basal inferior wall (8 patients, 33%). Patients with major depolarization criteria had a higher percentage of epicardial and endocardial scar as compared to those with no or minor depolarization criteria (respectively 93% [IQR] 59-100% versus 62% [IQR] 28-89%, p&amp;lt;0.0001 and 17% [IQR] 0-42% versus 4% [IQR] 0-23%, p=0.001). There was no significant difference of the percentage of epicardial or endocardial scar in patients with and without major repolarization criteria (respectively 90% [IQR] 49-98% versus 84% [IQR] 43-100%, p=0.91 and 14% [IQR] 11-35% versus 16% [IQR] 0-41%, p=0.73). Conclusion In ARVC, the electrical abnormalities predominate in the basal epicardium. Patients with major depolarization criteria had a higher extent of epicardial and endocardial scar, but there was an association between scar extent and repolarization abnormalities.

Risk stratification of severe ventricular arrhythmias in Brugada syndrome

Abstract Funding Acknowledgements Type of funding sources: None. Background Predicting likelihood of severe ventricular arrhythmias in Brugada syndrome (BrS) patients is challenging due to conflicting evidence. Objectives The goal of this study was to construct a prediction model of severe ventricular arrhythmias (VAs) for BrS patients. Methods Two hundred forty-two BrS patients were enrolled from 2008 to 2019 in a single-center cohort study. Those patients were followed up until December 2021. Clinical data and multiple ECG markers were collected and analyzed to determine the risk factors of severe VAs and sudden cardiac death (SCD). Multivariate logistic regression analysis was then used to develop a risk prediction model for adverse arrhythmic outcomes in BrS patients. Results During the follow-up (90.1 ± 45.8 months) of 242 BrS patients (mean age 42.3 ± 12 years; 94.6% male), 49 (20.2%) patients had syncope/pre-syncope due to VAs and 7 (2.9%) patients had aborted cardiac arrest. In multivariable analysis, epsilon wave, early repolarization sign, S wave duration in lead I, QRS duration in V2 and Tp-e duration were significant associated with adverse arrhythmic outcomes. A clinical model including these five significant predictors had a good performance to predict outcomes with balanced accuracy of 0.86 and area under curve of 0.93 (95% CI, 0.89-0.96, p &amp;lt; 0.001) indicating a good discriminative ability. Furthermore, the Hosmer–Lemeshow test and the calibration plot showed a good fit between the predicted and observed probabilities of the predictive model. Conclusions This study constructed a risk prediction model for severe VAs in BrS patients with a high predictive accuracy.

P454 ARRHYTHMIC RISK AND REPOLARIZATION ALTERATIONS ON THE ECG UNCOVERED BY AN ISOPRENALINE TEST

Abstract A 62–year–old man came to our attention for a syncopal episode that occurred during a competitive race, without prodromes, lasting a few seconds, with total, spontaneous regression and without issues. On ECG sinus bradycardia, HR 46/min and QRS fragmented in V1. During monitoring were documented many polymorphic premature ventricular complex (PVC) and polymorphic nonsustained ventricular tachycardia (NSVT). Coronary angiography showed normal coronary arteries. The Isoprenaline test was performed (intravenous infusion of Isoprenaline 0.2 mg in 100 ml of physiological solution at variable speed until obtaining a HR increase of at least 20% compared to baseline). As HR increased, a clear epsilon wave in V1 became evident. Also documented numerous polymorphic PVC and polymorphic NSVT. Cardiac magnetic resonance (MRI) was performed with documentation of findings suggestive of primary cardiomyopathy with biventricular phenotypic expression with a clear left prevalence. All these elements placed the patient at high arrhythmic risk. An implantable cardiac defibrillator was then performed. The isoprenaline–induced increase in heart rate made the epsilon wave manifest, which is an expression of an extremely delayed depolarization caused by the fibroadipose replacement of portions of the myocardium (as documented by cardiac MRI). It was also possible to exclude a J–wave syndrome in which the alterations are of repolarization and are due to the epi–endocardial electrical gradient which increases and becomes more evident at lower heart rates. The test with isoprenaline has therefore allowed us to distinguish depolarization disorders from repolarization disorders and to direct us towards the former.

Clinical Features, Genetic Findings, and Risk Stratification in Arrhythmogenic Right Ventricular Cardiomyopathy: Data From a Brazilian Cohort.

Arrhythmogenic right ventricular cardiomyopathy (ARVC), a rare inherited disease, causes ventricular tachycardia, sudden cardiac death, and heart failure (HF). We investigated ARVC clinical features, genetic findings, natural history, and the occurrence of life-threatening arrhythmic events (LTAEs), HF death, or heart transplantation (HF-death/HTx) to identify risk factors. The clinical course of 111 consecutive patients with definite ARVC, predictors of LTAE, HF-death/HTx, and combined events were analyzed in the entire cohort and in a subgroup of 40 patients without sustained ventricular arrhythmia before diagnosis. The 5-year cumulative probability of LTAE was 30% and HF-death/HTx was 10%. Predictors of HF-death/HTx were reduced right ventricle ejection fraction (HR: 0.93; P=0.010), HF symptoms (HR: 4.37; P=0.010), epsilon wave (HR: 4.99; P=0.015), and number of leads with low QRS voltage (HR: 1.28; P=0.001). Each additional lead with low QRS voltage increased the risk of HF-death/HTx by 28%. Predictors of LTAE were prior syncope (HR: 1.81; P=0.040), number of leads with T wave inversion (HR: 1.17; P=0.039), low QRS voltage (HR: 1.12; P=0.021), younger age (HR: 0.97; P=0.006), and prior ventricular arrhythmia/ventricular fibrillation (HR: 2.45; P=0.012). Each additional lead with low QRS voltage increased the risk of LTAE by 17%. In patients without ventricular arrhythmia before clinical diagnosis of ARVC, the number of leads with low QRS voltage (HR: 1.68; P=0.023) was independently associated with HF-death/HTx. Our study demonstrated the characteristics of a specific cohort with a high prevalence of arrhythmic burden at presentation, male predominance, younger age and HF severe outcomes. Our main results suggest that the presence and extension of low QRS voltage can be a risk predictor for HF-death/HTx in ARVC patients, regardless of the arrhythmic risk. This study can contribute to the global ARVC risk stratification, adding new insights to the international current scientific knowledge.

Characterisation of patients referred to a tertiary-level inherited cardiac condition clinic with suspected arrhythmogenic right ventricular cardiomyopathy (ARVC)

BackgroundArrhythmogenic right ventricular cardiomyopathy (ARVC) or arrhythmogenic cardiomyopathy is a rare inherited disease with incomplete penetrance and an environmental component. Although a rare disease, ARVC is a common cause of sudden cardiac death in young adults. Data on the different stages of ARVC remains scarce. The purpose of this study is to describe the initial presentation and cardiac phenotype of definite and non-definite ARVC for patients seen at a tertiary service.MethodsThis is a single centre, observational cohort study of patients with definite and non-definite ARVC seen at the Inherited Cardiac Conditions services at University Hospital Birmingham (UHB) in the period 2010–2021. Patients were identified by interrogation of digital health records, medical history, imaging and by examining 12-lead electrocardiograms (ECG).ResultThe records of 1451 patients were reviewed; of those, 165 patients were at risk of ARVC (mean age 41 ± 17 years, 56% male). 60 patients fulfilled task force criteria for definite ARVC diagnosis (n = 40, 67% males), and 38 (72%) of them carried a known pathogenic variant. The remaining 105 patients (50% males) were non-definite, and of these 45 (62%) carried a known pathogenic variant. Patients in the definite group were more symptomatic, with palpitations (57% vs. 17%), syncope (35% vs. 6%) and shortness of breath (28% vs. 5%, p < 0.001). T-wave inversion in V1-V3 and epsilon waves were observed only in the definite group. Both PR interval and QRS duration were longer in the definite (170 ± 34 ms and 100 ± 19 ms, p < 0.001) compared to (149 ± 25 and 91 ± 14 ms, p = 0.005). Patients with definite ARVC had significantly larger RV end diastolic areas and significantly reduced biventricular function (RVEDA = 27 ± 10 cm2, RVFAC = 37 ± 11% and EF = 56 ± 12%) compared to the non-definite group (RVEDA = 18 ± 4 cm2, RVFAC 49 ± 6% and LVEF 64 ± 7%, p < 0.001). Sustained ventricular tachycardia (VT) occurred more frequently in the definite group compared to the non-definite group (27% vs. 2%, p < 0.001). Ventricular fibrillation was observed in the definite group only (8 of 60 patients, 13%).ConclusionOur study showed differences between definite and non-definite ARVC patients in terms of clinical, electrophysiological and imaging features. Major adverse cardiac events occurred more commonly in the definite group, but also were observed in non-definite ARVC. This single centre observational cohort study forms a basis for further prospective multicentre interventional studies.

Unexplained Syncope With Abnormal ECG Findings in the Emergency Department: Don't Miss the Epsilon Wave!

Arrhythmogenic cardiomyopathy (AC) is a genetic cardiac disorder associated with sudden cardiac death, specifically in young adults (D. Corrado, C. Basso, & D. Judge, 2017). AC is a disease of the heart muscle fibers and it is not usually diagnosed until its advanced stages. Typical AC presentation in the emergency department (ED) includes cardiac syncope, palpitations, ventricular arrhythmias, or resolved cardiac arrest. The epsilon wave is the hallmark and the major electrocardiographic (ECG) diagnostic criterion for AC in the later stages of the disease process (A. R. Perez-Riera et al., 2019). A definite diagnosis of AC is of high complexity and not typically made by emergency providers; however, many cases of advanced AC are discovered in the ED as a result of syncope. The purpose of this case review is to discuss the typical presentation, ECG findings, and emergency providers' role in the management of patients with suspected AC.