Inherited cardiomyopathies mimicking arrhythmogenic right ventricular cardiomyopathy.
ABSTRACT Arrhythmogenic right ventricular cardiomyopathy (ARVC) represents an inherited cardiomyopathy that manifests clinically with malignant ventricular arrhythmias, sudden cardiac death, and less commonly heart failure. The condition is characterized by replacement of the myocardium, primarily of the right ventricle, with fibrofatty tissue. Extensive fibrofatty replacement of the myocardium has been previously thought to be pathognomonic of ARVC; however, this report details two other forms of inherited cardiomyopathy, namely hypertrophic cardiomyopathy (HCM) and the PRKAG2 cardiac syndrome, that were found to have significant fibrofatty myocardial replacement at pathologic examination. This report represents the first documentation of inherited cardiomyopathies mimicking ARVC and highlights the concept that other cardiac conditions can be associated with fibrofatty replacement of the myocardium.
Circulation 04/2014; 129(16):1703-11. DOI:10.1161/CIRCULATIONAHA.113.006932 · 14.95 Impact Factor
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ABSTRACT: Diagnosing arrhythmogenic right ventricular cardiomyopathy (ARVC) is often challenging because no single diagnostic tool is available to detect the disease. We evaluated whether analysis of plakoglobin, N-cadherin, and connexin-43 immunoreactivity can be used as a significant test in diagnosis of ARVC. We selected subjects with suspicion of ARVC (n=22) in patients who underwent endomyocardial biopsy (EMB) in Kyungpook National University Hospital (n=1326). The patients (n=22) were classified into definite ARVC patients (n=17) and borderline ARVC (n=5). We selected control subjects (n=20) who were autopsied and died of non-cardiac disease. Hematoxylin-eosin, Masson's trichrome, and immunohistochemical stains for plakoglobin, N-cadherin, and connexin-43 were used for all specimens. Reduced immunoreactivity of plakoglobin was observed in 13 (76%) of the 17 patients with a definite ARVC and in 4 (80%) of the 5 patients with a borderline ARVC. All subjects displayed no significant reduction of the immunoreactivity for connexin-43 as well as for N-cadherin. Our investigation revealed that the immunohistochemical analysis for plakoglobin had an accuracy of 81%, 76% sensitivity, and 84% specificity in diagnosis of ARVC. Results of our study showed that the immunohistochemical analysis of plakoglobin had a relatively high sensitivity and specificity in ARVC, but immunohistochemistry for plakoglobin alone could not be relied upon as a diagnostic test for ARVC. We confirmed that N-cadherin and connexin-43 had no diagnostic value in ARVC.International journal of clinical and experimental pathology 01/2013; 6(12):2928-35. · 1.78 Impact Factor
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ABSTRACT: The histopathological diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) can be challenging in forensic medicine. Immunohistochemical myocardial analysis for plakoglobin has been suggested as a new diagnostic test for ARVC. We examined this in the setting of forensic pathology, applying this method to forensic autopsy samples. We performed immunohistochemical staining for plakoglobin on 40 myocardial samples with an autopsy diagnosis of ARVC. In addition, histopathological reevaluation was performed applying the revised 2010 task force criteria including morphometric analysis. Myocardial samples from 15 subjects without heart disease were used as controls. Based on the histopathological reevaluation, 38 out of 40 cases were categorized as ARVC. A marked reduction in the plakoglobin staining was seen in 26 out of 38 myocardial samples in the ARVC-group. Of the two samples categorized as not ARVC, one showed reduced plakoglobin staining and one sample had normal staining. No control samples showed reduced plakoglobin staining. In conclusion, our study displayed reduced plakoglobin staining in approximately 2/3 of myocardial samples with ARVC. Our data suggests that immunostaining for plakoglobin might serve as an additional diagnostic marker of ARVC in forensic pathology, but additional validation is required.Forensic Science Medicine and Pathology 03/2015; 11(1). DOI:10.1007/s12024-014-9644-6 · 1.96 Impact Factor