Introduction: Arrhythmogenic right ventricular cardio myopathy (ARVC) is characterized by fi bro-fatty sub stitution of the myocardium in the right (RV) and, not infrequently, in the left ventricle (LV). The loss of normal myocardium and the development of scar tissue are associated with electrical instability manifested as ventricular arrhythmia and potential sudden death. A less common manifestation is right ventricular dysfunction causing heart failure and thromboembolism. Methods: We present the case of a 35 year old male patient, a smoker, without signifi cant medical history, who was admitted in our clinic owing to a first syncopal episode, preceded by palpitations and accompanied by convulsions and incontinence. The patient presented with palpitations that developed 6 months earlier, which generally occured during physical activity. He denied angina or low effort tolerance. Aft er the electric conversion: sinus rhythm, minor right bundle branch block, negative T waves in the V1-V3 derivations, epsilon wave. Results: Echocardiography: biventricular systolic dysfunction, with a left ventricular ejection fraction of 35%, retroactively interpreted as post-tachycardia myocardial sideration. The coronarography offered normal results. The symptomatic bradycardia occurred at the attempts of medical therapy, the non-sustained ventricular tachycardia during hospitalization, the severe systolic dysfunction of the RV and the probable implication of the left ventricle imposed the emergency implantation of a pacemaker/defibrillator. However, it has limited utility in the treatment of arrhythmogenic foci in ARVC owing to the patchy and progressive nature of the disease. It has been used with some success though, in limited cases as an alternative or adjunct to ICD to reduce the burden of ventricular tachycardia. Conclusions: Case of a young patient, without cardiologic medical history who was investigated for a syncopal episode occurred in an apparent state of health. Th is was relevant for ARVC, with major imaging modifications (electrocardiography, echocardiography and MRI) suggestive for a negative prognosis. Arrhythmogenic right ventricular dysplasia is a rare affliction that engages the vital prognosis. It must be systematically taken into consideration when resuscitated sudden death, syncope (especially during eff ort or in the case of young patients) or ventricular tachycardias with left bundle branch block occur.Th e short term prognosis depends on the severity of the arrhythmia, while the long term prognosis depends on the hemodynamic status, especially on the ventricular function.