Biography
Biography: Guy Hugues Fontaine
Abstract
Histologic demonstration of Atrial Dysplasia in ARVD patients
INTRODUCTION:
Arrhythmogenic Right Ventricular Dysplasia (ARVD) is mainly the result of desmosomal mutations. These mutations may affect both ventricles and atria. However, no histologic demonstration of this condition has been published yet.
OBJECTIVE:
To test the possible presence of a structural anomaly of the atrium in three patients who had ARVD ascertained by histologic material.
METHODS:
We included 3 patients who had typical ventricular histologic pattern of ARVD in whom atrial tissue was collected at autopsy. Histologic slides were obtained after current processing protocol with staining by H&E as well as HPS to have a better identification of bordering or embedding fibrosis which is the hallmark of ARVD.
RESULTS:
The three patients had fat and typical embedding fibrosis and adipocytes similar to what was observed on the right ventricular free wall of ARVD patients. However, one patient had a block of hyaline replacement fibrosis which represent the sequel of myocarditis which is a patchy phenomenon. It was therefore necessary to scrutinised the slides which demonstrated several zones of clusters of lymphocytes suggesting the form of chronic-active myocarditis. Therefore, ARVD patients have also atrial dysplasia which is observed clinically in 80% of cases (Camm HR 2013). The presence of lymphocytes suggests an active process which can be the trigger of arrhythmias (Bonny CRP 2010). As the quiescent form of ARVD is found in 3.7% of the general population there is a new mechanism to explain the frequency of lone atrial fibrillation in young adults in the general population.
CONCLUSION:
Histologic material of atrial dysplasia is demonstrated in patients with ascertained ARVD. The presence of hyaline blocks of fibrosis and clusters of lymphocytes is also similar to the right ventricular structure of ARVD patients. This may contribute to the explanation of the frequency of lone atrial fibrillation in young adults in the general population.