Clinical Differences in Japanese Patients Between Brugada Syndrome and Arrhythmogenic Right Ventricular Cardiomyopathy With Long-Term Follow-Up

Some Brugada syndrome (BrS) patients have been suspected of being in the initial state of arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aimed to clarify the electrocardiographic (ECG) and clinical differences between BrS and ARVC in long-term follow-up (mean 11.9 ± 6.3 years). A total of 50 BrS and 65 ARVC patients with fatal ventricular tachyarrhythmia (VTA) were evaluated according to the revised Task Force Criteria for ARVC. Based on the current diagnostic criteria concerning electrocardiographic, repolarization abnormality was positive in 2.0% and 2.6% of BrS patients at baseline and follow-up, and depolarization abnormality was positive in 6.0% and 12.8% of BrS patients at baseline and follow-up, respectively. At baseline, none of the BrS patients were definitively diagnosed with ARVC. Considering patients' lives since birth, Kaplan-Meier analysis revealed that age at first VTA attack showed the same tendency between the groups (BrS: mean 42.2 ± 12.5 years old vs ARVC: mean 44.8 ± 13.7 years old, log-rank p = 0.123). Moreover, the incidence of VTA recurrence was similar between the groups during follow-up (log-rank p = 0.906). Incidence of sustained monomorphic ventricular tachycardia was significantly higher in ARVC than in BrS whereas the opposite was true for ventricular fibrillation (log-rank p <0.001 and p <0.001, respectively). None of the diagnoses of BrS patients were changed to ARVC during follow-up. During long-term follow-up, although age at first VTA attack and VTA recurrence were similar, BrS consistently exhibited features that differed from those of ARVC.

An unusual case of sudden cardiac death during sexual intercourse

The most common cause of sudden death during sexual intercourse in adults is heart disease, and it is usually the male, whereas the death of the woman is unusual. Generally, in these cases, death occurs as a result of cardiovascular disease. The authors report an unusual case of the sudden death of a young woman during sexual intercourse. The post-mortem investigations (autopsy, cardiac nuclear magnetic resonance and cardiac histology) demonstrated a previously undiagnosed arrhythmogenic right ventricular cardiomyopathy. The terminal cause of death was a malignant arrhythmia from arrhythmogenic right ventricular cardiomyopathy. This is the first report of a case in which sexual activity can be regarded as the triggering factor combined with cardiac disease to the woman's death.

Usefulness of Genetic Study by Next-generation Sequencing in High-risk Arrhythmogenic Cardiomyopathy

INTRODUCTION AND OBJECTIVES

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by progressive fibrofatty replacement of predominantly right ventricular myocardium. This cardiomyopathy is a frequent cause of sudden cardiac death in young people and athletes. The aim of our study was to determine the incidence of pathological or likely pathological desmosomal mutations in patients with high-risk definite ARVC.

METHODS

This was an observational, retrospective cohort study, which included 36 patients diagnosed with high-risk ARVC in our hospital between January 1998 and January 2015. Genetic analysis was performed using next-generation sequencing.

RESULTS

Most patients were male (28 patients, 78%) with a mean age at diagnosis of 45 ± 18 years. A pathogenic or probably pathogenic desmosomal mutation was detected in 26 of the 35 index cases (74%): 5 nonsense, 14 frameshift, 1 splice, and 6 missense. Novel mutations were found in 15 patients (71%). The presence or absence of desmosomal mutations causing the disease and the type of mutation were not associated with specific electrocardiographic, clinical, arrhythmic, anatomic, or prognostic characteristics.

CONCLUSIONS

The incidence of pathological or likely pathological desmosomal mutations in ARVC is very high, with most mutations causing truncation. The presence of desmosomal mutations was not associated with prognosis.

Implantable Cardioverter-Defibrillator Therapy in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy: Predictors of Appropriate Therapy, Outcomes, and Complications

Background

Arrhythmogenic right ventricular dysplasia/cardiomyopathy is characterized by ventricular arrhythmias and sudden cardiac death. Once the diagnosis is established, risk stratification to determine whether implantable cardioverter‐defibrillator (ICD) placement is warranted is critical.

Methods and Results

The cohort included 312 patients (163 men, age at presentation 33.6±13.9 years) with definite arrhythmogenic right ventricular dysplasia/cardiomyopathy who received an ICD. Over 8.8±7.33 years, 186 participants (60%) had appropriate ICD therapy and 58 (19%) had an intervention for ventricular fibrillation/flutter. Ventricular tachycardia at presentation (hazard ratio [HR]: 1.86; 95% confidence interval [CI], 1.38–2.49; P<0.001), inducibility on electrophysiology study (HR: 3.14; 95% CI, 1.95–5.05; P<0.001), male sex (HR: 1.62; 95% CI, 1.20–2.19; P=0.001), inverted T waves in ≥3 precordial leads (HR: 1.66; 95% CI, 1.09–2.52; P=0.018), and premature ventricular contraction count ≥1000/24 hours (HR: 2.30; 95% CI, 1.32–4.00; P=0.003) were predictors of any appropriate ICD therapy. Inducibility at electrophysiology study (HR: 2.28; 95% CI, 1.10–4.70; P=0.025) remained as the only predictor after multivariable analysis. The predictors for ventricular fibrillation/flutter were premature ventricular contraction ≥1000/24 hours (HR: 4.39; 95% CI, 1.32–14.61; P=0.016), syncope (HR: 1.85; 95% CI, 1.10–3.11; P=0.021), aged ≤30 years at presentation (HR: 1.76; 95% CI, 1.04–3.00; P<0.036), and male sex (HR: 1.73; 95% CI, 1.01–2.97; P=0.046). Younger age at presentation (HR: 3.14; 95% CI, 1.32–7.48; P=0.010) and high premature ventricular contraction burden (HR: 4.43; 95% CI, 1.35–14.57; P<0.014) remained as independent predictors of ventricular fibrillation/flutter. Complications occurred in 66 participants (21%), and 64 (21%) had inappropriate ICD interventions. Overall mortality was low at 2%, and 4% underwent heart transplantation.

Conclusion

These findings represent an important step in identifying predictors of ICD therapy for potentially fatal ventricular fibrillation/flutter and should be considered when developing a risk stratification model for arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Safety, long-term outcomes and predictors of recurrence after first-line combined endoepicardial ventricular tachycardia substrate ablation in arrhythmogenic cardiomyopathy. Impact of arrhythmic substrate distribution pattern. A prospective multicentre study

BACKGROUND

First-line endoepicardial ventricular tachycardia (VT) ablation has been proposed for patients with arrhythmogenic cardiomyopathy (AC). This study reports procedural safety, outcomes, and predictors of recurrence.

METHODS AND RESULTS

Forty-one consecutive patients [12 with left ventricle (LV) involvement, 7 left-dominant] underwent first-line endoepicardial VT substrate ablation. Standard bipolar and unipolar thresholds were used to define low-voltage areas (LVA). Arrhythmogenic substrate area (ASA) was defined as the area containing electrograms with delayed components. Implantable cardioverter defibrillator interrogations were evaluated for VT recurrence. Epicardial LVA was larger in all cases (102.5 ± 78.6 vs. 19.3 ± 24.4 cm2; P< 0.001). Consistent with an epicardium-to-endocardium arrhythmogenic substrate progression pattern, epicardial ASA (epi-ASA) was negatively correlated with bipolar endocardial LVA (r = -0.368; P= 0.035) and with endocardial bipolar/unipolar-LVA (Bi/Uni-LVA) ratio (r= -0.38; P= 0.037). A Bi/Uni-LVA ratio >0.23 predicted an epi-ASA ≤10 cm2 (100% sensitivity, 84% specificity). Patients showing an epi-ASA < 10 cm2 required less epicardial (8.4 ± 5.8 vs. 25.3 ± 16; P= 0.045) and more endocardial (16.5 ± 8.6 vs. 7.5 ± 8.2; P= 0.047) radiofrequency applications. One patient with epi-ASA < 10 cm2 died of cardiac tamponade after epicardial puncture. Acute success (no VT inducibility after procedure) was achieved in 36 patients (90%). After 32.2 ± 21.8 months, 11 (26.8%) patients had VT recurrences. Left-dominant AC was associated with an increased risk of recurrence (HR = 3.41 [1.1-11.2], P= 0.044; log-rank P= 0.021).

CONCLUSION

First-line endoepicardial VT substrate ablation achieves good long-term results in AC. Left-dominant AC is associated with an increased risk of recurrence. The Bi/Uni-LVA ratio identifies patients with limited epicardial arrhythmogenic substrate in whom the indication of epicardial approach should be more cautiously assessed.

Adipositas cordis sudden death: a series of 79 patients

BACKGROUND

The principal aim of this study was to investigate the clinical, epidemiological and pathologic features for a series of 79 cases of adipositas cordis sudden death.

METHODS

We analyzed clinical and autopsy pathological features of 79 patients (43 females and 36 males) with adipositas cordis who died suddenly between 1975 and 2010. Data were extracted from China National Knowledge Infrastructure and Wan Fang Database.

RESULTS

The average age of the 79 cases was 36.6 ± 1.4 years old ranging from 13 to 68, and 82.3% of them were between 20 to 50 years old. Sudden death was the first symptom in 62 (78.5%) of the cases, only 17 (21.5%) had a history of chest distress or dyspnea. More than 4/5 (87.3%) of the cases had no any past medical history. At autopsy, the subjects' heart weight was mild or moderately increased, and a large amount of fatty tissues but not fibrous or fibro fatty was accumulated underneath the epicardium and infiltrated toward the right ventricle walls, and even infiltrated to all layers of the cardiac walls. Regional epidemiological data showed that about 80% of cases were living north and only 20% were living south of the Yangzi River, but not any familial heredity.

CONCLUSION

Adipositas cordis sudden death is a very severe disease, it occurs mostly in youth and middle-aged and sudden death is often the first symptom. There is a significant regional difference, but not any genetic correlation. The pathogenesis of adipositas cordis sudden death should to be further explored.

Nationwide (Denmark) study of symptoms preceding sudden death due to arrhythmogenic right ventricular cardiomyopathy

In this study, we investigated medical history and symptoms before death in all subjects aged 1 to 35 years who died a sudden cardiac death (SCD) from arrhythmogenic right ventricular cardiomyopathy (ARVC) in Denmark in the years 2000 to 2006. All deaths (n=6,629) in subjects aged 1 to 35 years in Denmark in the period 2000 to 2006 were included. A total of 16 cases of SCD due to ARVC were identified based on histopathologic examination. Information on medical history was retrieved from The National Patient Registry, general practitioners, and hospitals. Symptoms before death were compared with 2 control groups in the same age group and time interval: one consisting of subjects who died in traffic accidents (n=74) and the other consisting of patients who died a SCD due to coronary artery disease (CAD; n=34). In the case group, 8 of the 16 patients with ARVC experienced antecedent cardiac symptoms and 7 of them sought medical attention. None were diagnosed with ARVC before death. Only 1 patient in the healthy control group and 31 of the 39 patients with CAD experienced cardiac symptoms before death. A total of 6 patients of the 16 with ARVC died during strenuous physical activity and 4 of the deaths were sports-related SCDs. In conclusion, antecedent cardiac symptoms before SCD in the young were seen in 1/2 of the patients who died because of ARVC, and this is significantly higher than in the healthy control group. When considering the ARVC and CAD groups collectively, antecedent cardiac symptoms are seen in the majority.

Connexin defects underlie arrhythmogenic right ventricular cardiomyopathy in a novel mouse model

Arrhythmogenic right ventricular cardiomyopathy (ARVC) termed a 'disease of the desmosome' is an inherited cardiomyopathy that recently underwent reclassification owing to the identification of left-dominant and biventricular disease forms. Homozygous loss-of-function mutations in the desmosomal component, desmoplakin, are found in patients exhibiting a biventricular form of ARVC; however, no models recapitulate the postnatal hallmarks of the disease as seen in these patients. To gain insights into the homozygous loss-of-function effects of desmoplakin in the heart, we generated cardiomyocyte-specific desmoplakin-deficient mice (DSP-cKO) using ventricular myosin light chain-2-Cre mice. Homozygous DSP-cKO mice are viable but display early ultrastructural defects in desmosomal integrity leading to a cardiomyopathy reminiscent of a biventricular form of ARVC, which includes cell death and fibro-fatty replacement within the ventricle leading to biventricular dysfunction, failure and premature death. DSP-cKO mice also exhibited ventricular arrhythmias that are exacerbated with exercise and catecholamine stimulation. Furthermore, DSP-cKO hearts exhibited right ventricular conduction defects associated with loss of connexin 40 expression and electrical wavefront propagation defects associated with loss of connexin 43 expression. Dose-dependent assessment of the effects of loss of desmoplakin in neonatal ventricular cardiomyocytes revealed primary loss of connexin 43 levels, phosphorylation and function independent of the molecular dissociation of the mechanical junction complex and fibro-fatty manifestation associated with ARVC, suggesting a role for desmoplakin as a primary stabilizer of connexin integrity. In summary, we provide evidence for a novel mouse model, which is reminiscent of the postnatal onset of ARVC while highlighting mechanisms underlying a biventricular form of human ARVC.

[Arrhythmogenic right ventricular cardiomyopathy/dysplasia as a cause of sudden cardiac death]

The paper gives data on the prevalence of arrhythmogenic right ventricular cardiomyopathy/dysplasia as one of the common causes of sudden cardiac death, achievements in its molecular genetics, possible causes and cause-and-effect relations, microscopic and morphometric features of diagnosis.

Exercise-induced normalization of right precordial negative T waves in arrhythmogenic right ventricular cardiomyopathy

Negative T waves (NTWs) in right precordial leads (V₁ to V₃) may be observed on the electrocardiogram (ECG) of healthy subjects but can also represent the hallmark of an underlying arrhythmogenic right ventricular cardiomyopathy (ARVC). It has been a consistent observation that NTWs usually become upright with exercise in healthy subjects without underlying heart disease. No systematic study has evaluated exercise-induced changes of NTWs in ARVC. We assessed the prevalence and relation to the clinical phenotype of exercise-induced right precordial NTWs changes in 35 patients with ARVC (19 men, mean age 22.2 ± 6.2 years). Forty-one healthy subjects with right precordial NTWs served as controls. At peak of exercise (mean power 149 ± 43 W, mean heart rate 83.6 ± 12.6% of target), NTWs persisted in 3 patients with ARVC (9%), completely normalized in 12 (34%), and partially reverted in 20 (57%). Patients with ARVC with or without NTWs normalization showed a similar clinical phenotype. The overall prevalence of right precordial T waves changes during exercise (normalization plus partial reversal) did not differ between patients with ARVC and controls (92% vs 88%, p = 1.0), whereas there was a statistically nonsignificant trend toward a greater prevalence of complete normalization in controls (56% vs 34%, p = 0.06). In conclusion, our study demonstrated that right precordial NTWs partially or completely revert with exercise in most patients with ARVC, and NTWs normalization is unrelated to the clinical phenotype. Exercise-induced NTWs changes are inaccurate in differentiating between ARVC patients and benign repolarization abnormalities.

Predictors of appropriate ICD therapy in patients with arrhythmogenic right ventricular cardiomyopathy: long term experience of a tertiary care center

Introduction

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare genetically transmitted disease prone to ventricular arrhythmias. We therefore investigated the clinical, echocardiographical and electrophysiological predictors of appropriate implantable cardioverter defibrillator (ICD) therapy in patients with ARVC.

Methods

A retrospective analysis was performed in 26 patients (median age of 40 years at diagnosis, 21 males and 5 females) with ARVC who underwent ICD implantation.

Results

Over a median (range) follow-up period of 10 (2.7, 37) years, appropriate ICD therapy for ventricular arrhythmias was documented in 12 (46%) out of 26 patients. In all patients with appropriate ICD therapy the ICD was originally inserted for secondary prevention. Median time from ICD implantation to ICD therapy was 9 months (range 3.6, 54 months). History of heart failure was a significant predictor of appropriate ICD therapy (p = 0.033). Left ventricular disease involvement (p = 0.059) and age at implantation (p = 0.063) were borderline significant predictors. Patients with syncope at time of diagnosis were significantly less likely to receive ICD therapy (p = 0.02). Invasive electrophysiological testing was not significantly associated with appropriate ICD therapy.

Conclusion

In our cohort of patients with ARVC, history of heart failure was a significant predictor of appropriate ICD therapy, whereas left ventricular involvement and age at time of ICD implantation were of borderline significance. These predictors should be tested in larger prospective cohorts to optimize ICD therapy in this rare cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy: an update on pathophysiology, genetics, diagnosis, and risk stratification

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy accounting for life-threatening ventricular tachyarrhythmias and sudden death in young individuals and athletes. Over the past years, mutations in desmosomal genes have been identified as disease-causative. However, genetic heterogeneity and variable phenotypic expression alongside with diverse disease progression still render the evaluation of its prognostic implication difficult. ARVC was initially entered into the canon of cardiomyopathies of the World Health Organization in 1995, and international efforts have resulted in the 2010 modified diagnostic criteria for ARVC. Despite all additional insights into pathophysiology, clinical management, and modern risk stratification, under-/misdiagnosing of ARVC remains a problem and hampers reliable statements on the incidence, prevalence, and natural course of the disease.This review provides a comprehensive overview of the current literature on the pathogenesis, diagnosis, treatment, and prognosis of ARVC and sheds some light on potential new developments in these areas.

[Arrhythmogenic cardiomyopathy with predominant left ventricular involvement]

Arrhythmogenic right ventricular cardiomyopathy is a relatively well-defined clinical entity. This disease is characterized with right ventricular involvement and is an important cause of sudden cardiac death in young patients. However, arrhythmogenic cardiomyopathy with left-dominant involvement has recently been better described in the literature. This new presentation may be confused with other diseases such as idiopathic dilated cardiomyopathy. This review outlines left-dominant arrhythmogenic cardiomyopathy in the light of the most recent information.

Indications for implantable cardioverter defibrillator use for primary prevention of sudden cardiac death

The implantable cardioverter defibrillator (ICD) is used for primary and secondary prophylaxis of sudden cardiac death in high-risk patients. Although several trials have demonstrated the superiority of ICD over standard medical therapy or antiarrhythmic medication in this population, a few trials have not shown survival benefit. This review examines the major ICD trials that provide the basis for current therapy in this rapidly changing and very important area of cardiology.

Long-term follow-up and risk assessment of arrhythmogenic right ventricular dysplasia/cardiomyopathy: personal experience from different primary and tertiary centres

OBJECTIVES

Limited data are available on the course of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) because of the low frequency of this diagnosis. A long-term follow-up was analysed in typical ARVD/C patients from different primary and tertiary centres, and risk factors for sudden cardiac death (SCD) and end-stage heart failure were assessed.

METHODS AND RESULTS

A total of 313 patients (197 males) with a mean age of 44.8 +/- 16.5 years were included, with symptoms including aborted SCD (7%), ventricular arrhythmias (47%), additional chest pain (42%), syncopes (17%), and atrial arrhythmias (12%); follow-up duration was 8.5 years. The total annual mortality rate was 0.3%, from SCD in 0.2% and heart failure in 0.1%. In symptomatic or high-risk patients, the annual rate of malignant ventricular arrhythmias was 6 and 9%, respectively. In multivariate analysis, a risk factor for SCD was left ventricular dysfunction. The annual heart failure rate was low at 0.5%; four patients died, two had heart transplants and one tricuspid reconstruction. Intrathoracic cardioverter-defibrillator (ICD) therapy was initiated in 35 patients. Adequate shocks after 6-72 months were delivered in 77%; in the majority aborted sudden death with documented ventricular fibrillation and unstable ventricular tachycardia were underlying arrhythmias.

CONCLUSIONS

The clinical course of ARVD/C is characterized by a high rate of recurrent malignant ventricular arrhythmias in initially symptomatic and high-risk cases, and is uneventful in primarily asymptomatic affected individuals. The spectrum of clinical symptoms represents a warning symptom initiating the so-called 'hot phase' of the disease in many cases. ICD treatment is highly effective in cases of aborted SCD and unstable ventricular tachycardia.

Long-term efficacy of catheter ablation of ventricular tachycardia in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy

OBJECTIVES

This study sought to evaluate the outcomes of radiofrequency catheter ablation (RFA) of ventricular tachycardia (VT) in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) patients. Particular focus was placed on defining the single-procedure efficacy over long-term follow-up.

BACKGROUND

ARVD/C is an inherited cardiomyopathy characterized by VT and right ventricular dysfunction. Prior single-center studies have reported conflicting results concerning the efficacy of RFA of VT in ARVD/C patients.

METHODS

The study population comprised 24 patients (age 36 +/- 9 years, 11 male), enrolled in the Johns Hopkins ARVD registry, who underwent 1 or more RFA procedures for treatment of VT. Patients were followed up for 32 +/- 36 months (range 1 day to 12 years). Recurrence was defined as the documentation of VT subsequent to the procedure.

RESULTS

A total of 48 RFA procedures were performed using 3-dimensional electroanatomical (n = 10) or conventional (n = 38) mapping. Of these procedures, 22 (46%), 15 (31%), and 11 (23%) resulted in elimination of all inducible VTs, clinical VT but not all, and none of the inducible VTs, respectively. Forty (85%) procedures were followed by recurrence. The cumulative VT recurrence-free survival was 75%, 50%, and 25% after 1.5, 5, and 14 months, respectively. The cumulative VT recurrence-free survival did not differ by procedural success, mapping technique, or repetition of procedures. There was 1 procedure-related death.

CONCLUSIONS

Our study shows a high rate of recurrence in ARVD/C patients undergoing RFA of VT. This likely reflects the fact that ARVD/C is a diffuse cardiomyopathy with progressively evolving electrical substrate. Further studies are needed to define the precise role of RFA of VT in ARVD/C.

[Prevalence of sudden cardiac death during sports activities]

Sudden death during sport is a rare and unexpected event. It essentially affects young males, and a cardiomyopathy that had not been diagnosed during medical examinations is present in the majority of cases. In young subjects, there is generally hypertrophic cardiomyopathy or arhythmogenic right ventricular dysplasia. This is revealed during sporting activity, and sudden death is often the first symptom of the disease. Competitive sport increases the relative risk of sudden death to 2.5 compared to the risk in a non-sporting subject. The prevalence of sudden death during competitive sport is poorly understood. From the rare studies available, it could be estimated at 2.3/100,000 athletes per year. In Europe, it essentially occurs during football matches. However, the prevalence of sudden death during so-called 'recreational' sports is not precisely known. It could be much higher because these activities involve a larger number of people, and take place without supervision and usually without a medical examination beforehand. The participants are older, and coronary pathology is usually implicated.

[Sudden cardiac death in sports]

Sudden cardiac death in persons actively practicing in sports is usually due to cardiovascular disease. In athletes younger than 35 years, the most common diagnosis is hypertrophy of the left ventricle, an anomaly of the coronary arteries, acute myocarditis, or right-ventricular dysplasia. 80% of older athletes are found to have coronary heart disease. For those actively engaged in serious sports activities, such examinations as ECG, exercise ECG and echocardiogra phy are essential elements of medical screening. In the case of leisure sports activities, the German Society for Sports Medicine and Prevention recommend that a medical check be done before a person starts to seriously practice sport, with the aim of identifying cardiovascular factors or anomalies.

Arrhythmogenic right ventricular dysplasia: a United States experience

BACKGROUND

Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited cardiomyopathy characterized by right ventricular dysfunction and ventricular arrhythmias. The purpose of our study was to describe the presentation, clinical features, survival, and natural history of ARVD in a large cohort of patients from the United States.

METHODS AND RESULTS

The patient population included 100 ARVD patients (51 male; median age at presentation, 26 [interquartile range {IQR}, 18 to 38; range, 2 to 70] years). A familial pattern was observed in 32 patients. The most common presenting symptoms were palpitations, syncope, and sudden cardiac death (SCD) in 27%, 26%, and 23% of patients, respectively. Among those who were diagnosed while living (n=69), the median time between first presentation and diagnosis was 1 (range, 0 to 37) year. During a median follow-up of 6 (IQR, 2 to 13; range, 0 to 37) years, implantable cardioverter/defibrillators (ICD) were implanted in 47 patients, 29 of whom received an appropriate ICD discharge, including 3 patients who received the ICD for primary prevention. At follow-up, 66 patients were alive, of whom 44 had an ICD in place, 5 developed signs of heart failure, 2 had a heart transplant, and 18 were on drug therapy. Thirty-four patients died either at presentation (n=23: 21 SCD, 2 noncardiac deaths) or during follow-up (n=11: 10 SCD, 1 of biventricular heart failure), of whom only 3 were diagnosed while living and 1 had an ICD implanted. On Kaplan-Meier analysis, the median survival in the entire population was 60 years.

CONCLUSIONS

ARVD patients present between the second and fifth decades of life either with symptoms of palpitations and syncope associated with ventricular tachycardia or with SCD. Diagnosis is often delayed. Once diagnosed and treated with an ICD, mortality is low. There is a wide variation in presentation and course of ARVD patients, which can likely be explained by the genetic heterogeneity of the disease.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia mimicking rape homicide: a case report

Arrhythmogenic right ventricular cardiomyopathy (ARVC), also known as arrhythmogenic right ventricular dysplasia, is a known cause of sudden unexplained death in young, otherwise healthy adults. In the forensic setting, several cases of fatal ARVC have been reported, mostly occurring during physical exercise. However, a very few cases present where the death scene is mistaken for a homicide. We report here the case of a 23-year-old woman, found dead, lying in the snow on an isolated property. The woman's genitals were exposed, with her trousers down over her thighs. Rape homicide was strongly suspected, but autopsy findings proved otherwise.

The impact of implantable cardioverter-defibrillator therapy on survival in autosomal-dominant arrhythmogenic right ventricular cardiomyopathy (ARVD5)

OBJECTIVES

We sought to determine the impact of implantable cardioverter-defibrillator (ICD) therapy in patients with familial arrhythmogenic right ventricular cardiomyopathy (ARVC).

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy is a cause of sudden cardiac death, which may be prevented by ICD.

METHODS

We studied 11 families in which a 3p25 deoxyribonucleic acid (DNA) haplotype at locus ARVD5 segregated with disease and compared mortality in subjects who received an ICD with that in control subjects who were matched for age, gender, ARVC status, and family. Subjects (n = 367) at 50% a priori risk of inheriting ARVC were classified as high risk (HR) (n = 197), low risk (n = 92), or unknown (n = 78) on the basis of clinical events, DNA haplotyping, and/or pedigree position. Forty-eight HR subjects (30 males, [median age 32 years] and 18 females [median age 41 years]) were followed after ICD (secondary to ventricular tachycardia [VT] in 27%). Survival was compared with 58 HR control subjects who were alive at the same age to-the-day at which the ICD subject received the device.

RESULTS

In the HR group, 50% of males were dead by 39 years and females by 71 years: relative risk of death was 5.1 (95% confidence interval 3 to 8.5) for males. The five-year mortality rate after ICD in males was zero compared with 28% in control subjects (p = 0.009). Within five years, the ICD fired for VT in 70% and for VT >240 beats/min in 30%, with no difference in discharge rate when analyzed by ICD indication.

CONCLUSIONS

The unknown mutation at the ARVD5 locus causing ARVC results in high mortality. Risk stratification using genetic haplotyping and ICD therapy produced improved survival for males.

Circumstances of death and gross and microscopic observations in a series of 200 cases of sudden death associated with arrhythmogenic right ventricular cardiomyopathy and/or dysplasia

BACKGROUND

Sudden death is a possible consequence of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). Prevalence of ARVC/D in unexpected sudden cardiac death (USCD), however, remains imprecise, as do circumstances of death and ARVC/D-associated gross and microscopic findings, especially His bundle anomalies.

METHODS AND RESULTS

We reviewed 14 000 forensic autopsies required by judicial authorities from January 1980 to January 1999 in a 2 000 000-resident area. Age, gender, and circumstances of death were recorded. Hearts were examined macroscopically and microscopically. In this series, the ARVC/D group accounted for 200 consecutive cases (10.4%) of USCD, including 108 males and 92 females (average age 32.5 and 34.5 years, respectively). Nearly one third of deaths occurred during the fourth decade of life. Circumstances of death were various, but 75.6% occurred during everyday life events (at home, 63.1%; in the street, 6.6%; or at work, 6.1%); only 7 cases (3.5%) occurred during sports activity. Nineteen cases (9.5%) happened during the perioperative period. Adipose infiltration of the right ventricle was either isolated (20%) or associated with fibrosis (74.5%) and lymphocytes (5.5%). A total of 14.5% of cases had cardiac hypertrophy, assessed by an increase in heart weight and/or left ventricular wall thickness. In most cases, the His bundle and its branches were abnormal either because of infiltration of adipose tissue (8.1%), fibrosis (54.3%), or both (5.6%).

CONCLUSIONS

In ARVC/D, both sexes are equally affected, and there is a peak of risk during the fourth decade. Death most frequently occurs during sedentary activity. His abnormalities and left ventricular hypertrophy may be associated with ARVC/D.

Noninvasive risk stratification in arrhythmogenic right ventricular cardiomyopathy

The natural history of arrhythmogenic right ventricular cardiomyopathy is determined by the electrical instability of the dystrophic myocardium, which can precipitate arrhythmic cardiac arrest any time during the course of the disease and by the progressive myocardial loss that results in ventricular dysfunction and heart failure. Sudden death accounts for the majority of the fatal events but its occurrence is mostly unpredictable. There are no prospective and controlled studies assessing clinical markers that can predict the occurrence of life-threatening ventricular arrhythmias. However, the noninvasive risk profile, which emerges from retrospective analysis of clinical and pathologic series, is characterized by history of syncope, physical exercise, spontaneous ventricular tachycardia or ventricular fibrillation, right ventricular dysfunction, left ventricular involvement, right precordial negative T wave, right bundle branch block, QT-QRS dispersion, right precordial ST-segment elevation and late potentials. At present only QRS dispersion, history of syncope and right and/or left ventricular abnormalities at radionuclide angiography proved to be independent noninvasive predictors of sudden death.

T-Wave Alternans in Patients with Right Ventricular Tachycardia

Microvolt T-wave alternans has been proposed as a new risk marker for ventricular arrhythmias. However, the clinical significance of T-wave alternans in patients with ventricular tachycardia (VT) originating from the right ventricle has been unknown. The study population consisted of 20 patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) or idiopathic VT. T-wave alternans was measured during bicycle exercise testing using the CH 2000 system. Of the 7 patients with ARVC, 6 (86%) were positive for T-wave alternans. On the other hand, only 1 (8%) of 13 patients with idiopathic VT originating from the right-ventricular outflow tract was positive for T-wave alternans.

Arrhythmogenic Right Ventricular Cardiomyopathy and Sudden Cardiac Death in Young Koreans

The aim of this study was to assess the frequency and clinical characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC) in young victims of sudden cardiac death (SCD). From January 1999 to December 2000, postmortem studies were conducted in 38 cases of SCD (age < or =35 (27+/-7) years old, 26 male) from the Taegu-Kyungpook region of southeastern Korea. Cases of sudden infant death syndrome were excluded. The causes of SCD were ARVC in 42%, acute myocardial infarction in 11%, myocarditis in 11%, pulmonary embolism in 8%, hypertrophic cardiomyopathy in 5%, aortic rupture in 3%, aortic stenosis in 3%, and unknown in 18%. The mean age of the 16 ARVC victims was 27+/-5 years and 10 were male. None were competitive athletes, or had been suspected of having cardiovascular disease before death. SCD was not related to vigorous physical or competitive activity and occurred during sleep in 7 cases, during work in 4, during bathing in 2, while driving, praying and eating in 1 case each. ARVC is an important cause of SCD in young people in this area of Korea.

Right bundle branch block, right precordial st-segment elevation, and sudden death in young people

BACKGROUND

Patients with the ECG pattern of right bundle branch block and right precordial ST-segment elevation may experience sudden death in the setting of either arrhythmogenic right ventricular cardiomyopathy (ARVC) or a functional electrical disorder such as Brugada syndrome.

METHODS AND RESULTS

Among a series of 273 young (</=35 years) victims of cardiovascular sudden death who were prospectively studied from 1979 to 1998 in the Veneto Region of Italy, 12-lead ECG was available in 96 cases. Thirteen (14%; 12 males and 1 female aged 24+/-8 years) had right precordial ST-segment elevation, either isolated (9 cases) or associated with right bundle branch block (4 cases). At autopsy, all patients had ARVC (92%) except one, who had no evidence of structural heart disease. Compared with the 19 young sudden death victims with ARVC and no ST-segment abnormalities from the same series, those with AVRC and right precordial ST-segment elevation included fewer competitive athletes (17% versus 58%; P:=0.03), more often died suddenly at rest or during sleep (83% versus 26%; P:=0.003), and showed serial ECG changes over time (83% versus 0; P:=0.015), polymorphic ventricular tachycardia (33% versus 0; P:=0.016), and predominant fatty replacement of the right ventricular anterior wall (58% versus 21%; P:=0.05),

CONCLUSIONS

Right precordial ST-segment elevation was found in 14% of young sudden death victims with available ECG. It mostly reflected underlying ARVC with predominant right ventricular anterior wall involvement and characterized a subgroup of patients who share with Brugada patients the propensity to die from non-exercise-related cardiac arrest and to exhibit dynamic ECG changes and polymorphic ventricular tachycardia.

Ventricular tachycardia catheter ablation in arrhythmogenic right ventricular dysplasia: a 16-year experience

Arrhythmogenic right ventricular dysplasia (ARVD) is a structural heart disease affecting young adults that leads to cardiac rhythm disorders including supraventricular and mostly ventricular arrhythmias. Sudden death may be the first presentation of the disease. Ablation techniques have been used for the treatment of ventricular tachycardia in cases resistant to drug therapy. Radiofrequency is appropriate as a first approach for ventricular tachycardia ablation in ARVD; however, its effectiveness is less than 40% at the first session. Fulguration is effective for ventricular tachy-cardia ablation and should be used in the same session after ineffective radiofrequency ablation. However, fulguration requires expertise, general anesthesia, and more than one session in half of all patients. Radiofrequency and fulguration plus other common forms of treatment including pacemakers and automatic implantable cardioverter defibrillators provides a clinical success rate of 81% to 93% in a series of 50 consecutive patients studied during 16 years. Earlier poor reputation of fulguration was the result of poorly understood technical problems concerning the physics and biophysics of the procedure under control with presently available methods. This in-depth study of a large population over a long time period demonstrates that fulguration should be rehabilitated.

Unsuspected cardiac lesions associated with sudden unexpected perioperative death

The retrospective analysis of 1700 forensic autopsies over 17 years (1981-97) following unexpected sudden cardiac death revealed a group of 50 cases that could have been related to surgery and/or anaesthesia. Patients were young with no history of cardiac disease. Surgery was performed for uncomplicated disorders, all classified as ASA 1. Cardiac arrest took place at induction of anaesthesia in 16% of cases, during surgery in 64% and at the end of surgery in 20%. Investigation and expertise reports ordered by the public prosecutor revealed none of the typical causes of death usually associated with surgery or anaesthesia. Pathological examination showed cardiac lesions in 47 cases: arrhythmogenic right ventricular cardiomyopathy in 18 cases, coronary artery disease in 10 cases, cardiomyopathy in eight cases, structural abnormalities of the His bundle in nine cases, mitral valve prolapse in one case, and acute myocarditis in one case. Identification of the cause of death of patients at low risk may provide major relief to the family of the patient and the medical staff.

Follow-up of patients with arrhythmogenic right ventricular cardiomyopathy dysplasia

OBJECTIVE

The enlargement of data on the natural course and management of patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D).

DESIGN

Retrospective and partly prospective observational study.

SETTING

Cardiac Unit, Wentworth Hospital, Durban--the only unit in KwaZulu-Natal providing an arrhythmia and electrophysiology service.

STUDY POPULATION

Those included were: (i) patients referred for palpitations, unexplained syncope, or ventricular tachycardia and in whom ARVC/D was diagnosed according to multiple criteria; and (ii) family members of patients with ARVC/D in whom the disease was documented using the same criteria.

MAIN OUTCOME AND MEASUREMENTS

Diagnosis, management, morbidity and mortality were analysed.

RESULTS

Twelve patients were diagnosed with ARVC/D over a period or 6 years. At the end of follow-up for 3.4 +/- 3.2 years, 7 of them were well and alive on anti-arrhythmic medication, 2 were asymptomatic, and 3 had died. One death was sudden, 1 patient died due to left ventricular failure, and 1 patient died due to a low cardiac output syndrome 3 months after right ventricular isolation, i.e. the mortality rate was 25%. ARVC/D was found in all racial groups and was familial in 5 patients (42%). In all but one patient the correct diagnosis was not suspected by the referring institution, physician or cardiologist.

CONCLUSIONS

ARVC/D needs to be included into a differential diagnosis of unexplained syncope, palpitations, or ventricular tachycardia by all health service providers. Its management remains a complex challenge with varying results.

Heart failure in arrhythmogenic right ventricular dysplasia-cardiomyopathy

Sudden arrhythmic death and heart failure are essential factors influencing the prognosis of arrhythmogenic right ventricular dysplasia-cardiomyopathy. Heart failure is a rare, but often lethargic event although little is known about morphology, time course and non-invasive predictors.

METHOD

In a retrospective study of a consecutive cohort of 121 patients with ARVD over a follow-up period of up to 12 years morphological features of heart failure, time course from the initial diagnosis and standard 12-lead ECG as a non-invasive predictor of developing heart failure were analysed.

RESULTS

Heart failure occurred in 13 patients (11%) with isolated right ventricular dilatation and loss of function in 10 cases (77%) and biventricular failure in three cases (23%). Patients developed NYHA class IV in four cases, class III-IV in two cases and class II in seven cases in 4-8 years. In standard ECG of 12 patients (92%) complete right bundle branch block was present at the time of initial diagnosis (n=6) or in a time interval of 4 years (n=6). Morphological distinction of isolated right and biventricular heart failure could be achieved not only by imaging techniques such as echocardiography or cardioangiography, but also by standard ECG with right atrial hypertrophy and an increased mean precordial QRS dispersion of 47.1+/-18.9 ms in cases of right heart failure and biatrial hypertrophy and a reduced precordial QRS dispersion of 33.0+/-23.1 ms in cases of biventricular heart failure.

CONCLUSIONS

Heart failure in ARVD consists of isolated right ventricular and biventricular dilatation and pump failure in a time course of 4-8 years after developing complete right bundle branch block as a strong non-invasive predictor from standard 12-lead ECG.

Risk stratification of sudden cardiac death and malignant ventricular arrhythmias in right ventricular dysplasia-cardiomyopathy

Arrhythmogenic right ventricular dysplasia-cardiomyopathy is in most cases a benign cause of ventricular arrhythmias in young patients. The major reason of mortality is sudden arrhythmic death with an annual rate of 2-3% as the first manifestation of the disease in most cases. Little is known about risk factors of sudden arrhythmic death so far. The purpose of the retrospective study was to classify risk factors from invasive and non-invasive examinations.

METHODS

In a cohort of 121 consecutive patients sampled from 1986 to 1998 the value of right ventricular dilatation, left ventricular involvement analysed by angiocardiography or echocardiography and standard ECG parameters such as precordial T wave inversions, right precordial ST elevation, precordial QRS dispersion, left precordial JT interval prolongation and complete right bundle branch block were determined. The whole cohort of patients were divided into two groups with high arrhythmic risk (aborted or non-aborted sudden death, recurrent ventricular tachycardia despite medical treatment, recurrent syncopes) and low risk (frequent ventricular premature beats, non sustained ventricular tachycardia, uneventful course under medical therapy).

RESULTS

From angiocardiography or echocardiography in a quantitative approach right ventricular dilatation (p<0.0001) and additional left ventricular abnormalities (p<0.0001) could be identified as major risk factors. From an ECG point of view increased precordial QRS dispersion > or =50 ms (p<0.01) with complete right bundle branch block and right ventricular dilatation in most cases and precordial T wave inversions beyond V3 (p<0.0001) and the phenomenon of left precordial JT interval prolongation (JT dispersion > or =30 ms) in cases of additional left ventricular abnormalities represented non-invasive predictors of recurrent arrhythmic events. Right precordial ST segment elevation could be excluded as risk factor of sudden arrhythmic death.

CONCLUSIONS

Right ventricular dilatation with ECG depolarisation abnormalities and additional left ventricular involvement with striking ECG repolarisation abnormalities could be identified as strong risk factors of recurrent arrhythmic events in ARVD with unfavorable prognosis.

[Arrhythmogenic cardiomyopathy as cause of sudden death in Spain. Report of 21 cases]

INTRODUCTION AND OBJECTIVES

Arrhythmogenic cardiomyopathy is a myocardial disease of unknown origin characterized by progressive replacement of right and/or left ventricular myocardium by fibrofatty tissue. Young adult people are more frequently affected and symptoms include palpitations, syncopes or sudden death. The objective of this study is to assess the frequency and characteristics of arrhythmogenic cardiomyopathy as a cause of sudden death in a series of cases in Spain.

MATERIAL AND METHODS

Among the sudden death cases studied at the Toxicology Institute of Madrid between 1991 and 1997, those with arrhythmogenic cardiomyopathy diagnosis were analysed.

RESULTS

21 cases were diagnosed (0.62% of all sudden deaths and 6.8% of sudden deaths under 35 years). There were 20 males and one female (mean age 24.5 +/- 9.37 years); eleven (52.3%) died during sport activity and 8 (38%) had previous exercise related symptoms. In only two cases other members of the family had died suddenly and only one had been diagnosed in life. Biventricular involvement was observed in 13 cases; isolated involvement of the left ventricle in 4, and isolated involvement of the right ventricle in 4.

CONCLUSIONS

Arrhythmogenic cardiomyopathy is a relatively frequent cause of sudden death in the young population in Spain. It is very often the first manifestation of the disease. The myocardial involvement is more frequently biventricular than isolated in the right ventricle. The diagnosis could be difficult for cardiologists, pathologists and forensic doctors.

Cardiac arrest and sudden death in competitive athletes with arrhythmogenic right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia (ARVD) is a predisposing factor for sport-related cardiac arrest (CA), sudden cardiac death (SD), and life-threatening ventricular tachyarrhythmias (VT). The aim of this study was the assessment of athletes with ARVD, particularly the CA survivors. From 1974 to January 1996, 1642 competitive athletes (aver. 25.5 yr.), 136 of whom were top level athletes (TLA), were studied for important arrhythmic manifestations. All athletes underwent an individualised study protocol including a series of non invasive and invasive diagnostic techniques. One hundred and one athletes (90 males, 11 females, aver. 25.9 yr.) were diagnosed as being affected by ARVD on the basis of the WHO/ISFC criteria. The same percentage (about 6%) of ARVD is present in both the general arrhythmic athletes population and in the subgroup of TLA. Prevalence of ARVD among athletes with CA or SD is high (respectively 23% and 25%), confirming the observation that ARVD is one of the major causes of SD in Italian athletes. All CA were athletic activity related, indicating the potentiality of exercise as a cause of electrical destabilisation in subjects with ARVD. In athletes with documented ARVD intense sport activity has to be proscribed. In athletes at risk of CA or SD an aggressive treatment, ICD implantation and RF catheter ablation must be taken into consideration.