Histo-Molecular Analysis of 25 Cases of Arrhythmogenic Right Ventricular Cardiomyopathy.
Vidhya Nair, Jagdish Butany. Hamilton Health Sciences, Hamilton, Canada; McMaster University, Hamilton, Canada; University Health Network, Toronto, Canada; University of Toronto, ON, Canada
Background: Analyze histopathological changes in the hearts with a diagnosis of ARVC; study the incidence of PKP2 mutation in this population and to characterize if possible the histological changes associated with the mutation.
Design: All ARVC cases diagnosed in the past 20 years were reviewed. Clinical data including the patient's age, sex, were recorded. PKP2 mutation analysis was done on all the cases.
Results: There were 3 autopsy cases, where the patients had a sudden death due to ARVC while 22 were surgical explants. The age ranged from 18 to 66 years. There were 16 females and 9 males. The hearts weighed from 260 to 816 grams. Right ventricular thinning was seen in 24 cases, while 14 cases showed an apical aneurysm. Fibro fatty infiltration of the right ventricle was seen in 24 cases, predominantly fat infiltration was seen in six cases while one case showed only fat infiltration. Fibrosis of the trabeculae carne was seen in 22 cases. Lymphocytes in the right ventricle were seen in 5 cases. Fibrosis of the left ventricle was seen in all 25 cases. (Subepicardial band like fibrosis was in 5cases, subendocardial fibrosis in 4, mid ventricular in 1.transmural in one and the rest showed an interstitial pattern.) Myocyte disarray was seen in 6 cases. Myocarditis was seen in 12 cases (2 cases of active myocarditis, 2 cases of eosinophilic, 1 borderline, 1 healing). Significant fibrosis involving the atria was seen in 18 cases. PKP 2 mutation was seen in 23 of 25 cases (92%). All mutations have previously been described. 14 cases (56%) had a mutation in the intronic site with no change in protein. 9 (36%) cases showed mutation on an exon that might have changes of protein.(4 of these cases had an additional mutation in the intronic site).
|Mutation in intron||Mutation in exon|
|Female to male ratio||5:2||5:4|
|Myocarditis||5 cases||6 cases|