Arrhythmogenic right ventricular cardiomyopathy in two pairs of monozygotic twins.

UNLABELLED: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inheritant disease with an autosomal dominant mode of transmission with incomplete penetrance and variable expression. Linkage analysis in affected families succeeds in identifying 9 loci determining 9 subtypes of the disease. Genotype phenotype correlation is unclear and the influence of various environmental factors is discussed. OBJECTIVES: Genotype phenotype correlation in 2 pairs of monozygotic twins with ARVC and the role of environmental factors are analyzed. PATIENTS AND METHODS: Among 40 pts with ARVC and their 195 relatives there were 2 pairs of monozygotic twins: brothers, age 47 y; and sisters, age 48 y. History, ECG, Holter monitoring, 2D and Doppler Echo, and MRI were analyzed. RESULTS: Twin brothers: ARVC was diagnosed in the proband after the episode of VT with LBBB morphology (enlarged right ventricle, focal hypokinesia of apex, MR evidence of adipose tissue in RV wall). Identical morphology of RV was seen in asymptomatic twin brother. The patient presenting arrhythmia has been rowing for 4 years. Twin sisters: diagnosis was done during family screening. Both were asymptomatic. RV morphology typical for ARVC was found discrete in one of them (bulges adipose tissue in the RV apex); the latter showed changes suggesting RV abnormality (mild segmental dilatation of infundibulum, adipose tissue in a free wall of the RV). No differences in previous viral infections and sports involvement were observed. CONCLUSIONS: 1. Clinical picture of ARVC in monozygotic twins is not identical. 2. Strenuous effort may be a factor triggering the arrhythmia in pts with ARVC.

Familial form of arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Arrhythmogenic right ventricular dysplasia (ARVD) is characterised by fatty and fibrous infiltration of myocardial muscle. Clinical symptoms include dangerous cardiac arrhythmias and heart failure in the advanced form of the disease. ARVD is genetically determined in at least 50% of cases and is characterised by a marked variability of clinical presentation within one family. AIM: To assess the prevalence of the familial form of ARVD in Poland, the mode of inheritance and the risk of sudden cardiac death as well as heart failure development in asymptomatic patients, in whom ARVD was detected during family screening. METHODS: 211 relatives of 40 patients with ARVD were examined. Thirty two families were identified in which at least two members had the disease. The analysed parameters included family history, physical examination, ECG, echocardiography and magnetic resonance. RESULTS: Abnormalities of the right ventricle and/or cardiac arrhythmias suggesting ARVD were found in 71 subjects (mean age 32.4 years). In 28 cases ARVD was diagnosed. From this group, one patient had aborted sudden death. In the remaining 43 subjects a borderline form of the disease was detected. Of this group, one patient died suddenly. The degree of morphological changes in cardiac muscle correlated with patients' age. CONCLUSIONS: 1. The familial form of ARVD is frequent in Poland. 2. ARVD is inherited in an autosomal dominant mode. 3. Sudden cardiac death may be the first symptom of the disease, even in subjects with borderline ARVD. 4. ARVD is a progressive disease. Concomitant left ventricular involvement is not rare and probably represents a late stage of the disease.

[Arrhythmogenic right ventricular cardiomyopathy (dysplasia): etiology, clinical presentation, diagnosis and treatment]. / Arytmogenna kardiomiopatia (dysplazja) prawej komory. Etiologia, objawy, diagnostyka i leczenie.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disorder characterised by progressive replacement of right ventricle myocardium by either segmental or diffuse fibro-fatty tissue, often with the involvement of the left ventricular wall and manifestations of arrhythmia. Familial occurrence with autosomal dominant inheritance, variable expression and incomplete penetrance is estimated as 1/5000. The recessive form called Naxos disease has also been reported. The etiology and pathogenesis of ARVC are still unknown. Advanced theories of inflammatory or infective etiology and possible mechanism of myocyte loss through apoptosis and/or transdifferentiation into adipocytes are presented in this article. The patterns of two distinct pathomorphology of ARVC based on the nature of myocardial replacement are also presented. The presentation encompasses the wide spectrum of clinical diagnostic features of the disease, including sudden death in the family and abnormalities in ECG, Echo, MRI, angiography, PES exhibiting morphologic and functional changes, and replacement of myocytes by fibro-fatty tissue observed in endomyocardial biopsy specimens. Special attention is drawn to the subtle clinical manifestations and ECG clues of the disease in children and young people. Treatment modalities including drug therapy, ablation, implantable cardioverter defibrillators, antiarrhythmic surgery or heart transplantation are also presented.