[Atrial involvement in arrhythmogenic right ventricular dysplasia: primary or secondary? Description of a case of occult ventricular dysplasia with right atrial enlargement and exclusively sinoatrial arrhythmia].

The atrial involvement in patients with arrhythmogenic right ventricular dysplasia is very rarely described. We here describe a patient with right atrial enlargement suffering from classical sinus and atrial electrical disease (tachycardia-bradycardia syndrome); the associated echo-angiographic aspects of the right ventricle are compatible, even in the absence of ventricular tachyarrhythmias, with a concealed form of right ventricular dysplasia. A common pathogenetic mechanism for the atrial and ventricular involvement is hypothetically considered.