16^th World Cardiology Congress

Biography

Biography: Guy Hugues Fontaine

Abstract

During a discussion in an International meeting held in Marrakech between Walter Somerville (Editor in Chief of the British Heart Journal) and Jean Francois Goodwin (father of cardiomyopathies) it was suggested that some form of “disarray” which is the classical marker of Hypertrophic Cardiomyopathy (HCM) can be observed in the normal heart especially on the diaphragmatic aspect of the right ventricle close to the septum. As in the disease that I recently identified called Arrhythmogenic Right Ventricular Dysplasia (ARVD) presence of adipocytes (instead of disarray) was one of the features of this disease, it was logical to check if presence of fat was observable in the right ventricle of a normal individual. This lead to the examination of the right ventricle of 82 individuals from 15-75 years old who died of a non-cardiac cause in a general hospital of Paris. Surprisingly compact normal myocardium was observed in only 30% of the cases. 60% showed various grades of strands of adipocytes mixed with normal cardiomyocytes. This included 3.7% who had the histologic pattern of RVD and not ARVD since those individuals had non arrhythmias. Therefore, these cases represent the quiescent form of ARVD. 

Some typical ARVD patients enter the disease by atrial arrhythmias such as atrial extrasystole, flutter and atrial fibrillation (Saguner Circulation 2014). It was therefore suspected that the disease which affect the right ventricle is also affecting the atrium. Histology is the gold standard to diagnose ARVD. It was therefore possible to analyse the histologic structure of the atrium and subsequently to consider if the same situation exists in the general population as far as atrial dysplasia is concerned. In my clinical experience I had two ARVD patients who died of a non-cardiac cause in the hospital anf had immediate extraction of the heart in excellent technical condition. Therefore, it was possible to have samples of tissue from the four cavities confirming in the atrium the histologic structure found in the right ventricle of ARVD patients. The main consequence of this new discovery is to identify the possible mechanism of atrial fibrillation. Finally atrial dysplasia may lead to atrial fibrillation spontaneously because of the creation of an anatomic substrate or it could be a more stable form which become arrhythmogenic only in case of superimposed myocarditis (Bonny CRP 2001).