Arrythmogenic right ventricular cardiomyopathy/dysplasia and “idiopathic” premature ventricular contractions: diagnosis in young patients

Idiopathic arrhythmias are heart rhythm and conduction abnormalities in patients without structural heart abnormalities, or more precisely, arrhythmias with unknown causes. However, a complex examination of the patient reveals the cause of arrhythmia in more than 94% cases. A patient, 28, with complains of palpitations, was referred to our clinic with a diagnosis of “idiopathic premature ventricular contractions”. The 24-hour ECG monitoring detected 14326 premature ventricular contractions. The standard clinical tests did not reveal the cause of arrhythmia. Further diagnostic evaluation was focused on verification/exclusion of congenital cardiomyopathies and chronic myocarditis. The heart MRI revealed significant right ventricular dilatation and regional dyskinesia. The signal averaged ECG found late potentials. Thus, there are at least 1 major and 2 minor criteria of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) according to the modified 2010Task Force Criteria. In addition, a concomitant chronic immune myocarditis was diagnosed, which is typical for ARVD. This diagnosis was based on triple elevated titers of anti-heart antibodies and late enhancement revealed by magnetic resonance imaging. Consequently, idiopathic arrhythmias in young patients should not be considered a final diagnosis, but should be a signal for further careful clinical evaluation.