Arrhythmogenic Cardiomyopathy: A Biventricular Disease with Predilection for African-Americans
A Burke, N Cresswell, R Kutys, L Li. Armed Forces Institute of Pathology, Washington, DC; CVPath Institute, Inc, Gaithersburg, MD; University of Maryland, Baltimore, MD
Background: The ventricular distribution of arrhythmogenic cardiomyopathy (AC) in sudden death has not been studied in detail, especially in relation to racial and exertional status. There have been few immunohistochemical studies of sarcomeric related proteins.
Design: Fifty cases of sudden cardiac death with the diagnosis of AC were retrospectively studied. Distribution of disease as determined grossly and microscopically was correlated with activity at time of death, race, and presence of inflammation. AC was defined as subepicardial or right ventricular fibrofatty change surrounding altered cardiac myocytes with disordered myofilaments and vacuolated cytoplasm. Racial and gender incidence was compared to 500 cases of sudden cardiac death due to other causes seen in consultation during the same time period. Immunohistochemical stains for connexin-43, desmin, alpha tubulin, sarcomeric actin were performed on AC cases.
Results: There were 23 whites (44%), 25 blacks (50%), and 2 Asians (6%) with AC; the proportion of blacks was greater than the non-AC sudden deaths (50% vs. 34%, p=.01). Death was exertional in 29 cases (58%) vs. 5% for non-AC SD (p<.0001) and there were 7 women (14%) vs. 26% for non-AC sudden death (p=.05). Extent of disease was predominantly right ventricular in 6 (12%, age 255 years), biventricular in 25 (50%, age 363 years), and left ventricular (ALVC) in 19 (38%, age 373 years), with some overlap in 38 (76%). There was no difference in proportion of blacks by ventricular distribution (p>.9). RV dilatation was present in 22 (44%) and aneurysms were present in 2 (4%); there was no correlation between RV dilatation and race or exertion. The proportion of exertional deaths was greatest in right ventricular AC (ARVC, 83%) followed by ALVC (58%) and biventricular (50%, p=0.2). Inflammation was present in 44% of biventricular AC, vs. 74% of LVNC and 83% of ARVC (p=.05). Immunohistochemical staining for sarcomeric proteins (sarcomeric actin), desmin, alpha tubulin and connexin-43 demonstrated disruption of myofilaments in areas of scarring, but no abnormalities in areas remote from fibrofatty or inflammatory infiltrates.
Conclusions: Arrhythmogenic cardiomyopathy, when presenting with sudden death, is usually biventricular, with inflammation more predominant in RV involvement. There may be a predilection for African-Americans. Sarcomeric structure appears normal in non-involved areas.
Tuesday, March 10, 2009 1:00 PM
Poster Session IV # 49, Tuesday Afternoon