Prospective, nonrandomized, single-center, comparative study to define if right ventricular (RV) contractile reserve assessed by exercise CMR helps to improve the differential diagnosis between pathological and physiological remodeling of the RV; ie. arrhythmogenic right ventricular cardiomyopathy (ARVC) and athlete's heart.

Comparison of the RV contractile reserve in 4 groups of patients: Arrhythmogenic right ventricular cardiomyopathy (ARVC) patients; endurance athletes with a dilated RV, endurance athletes with normal RV, untrained subject with normal RV.

Patients will come to the hospital for 3 visits (3 half days):

• Visit 1: clinical evaluation, rest ECG, rest echocardiography, cardio-pulmonary exercise test.
• Visit 2: exercise echocardiography, holter ECG monitor (48 yours)
• Visit 3: rest CMR and exercise CMR (ergocycle)

Inclusion Criteria:

• Men or women aged 18 years and older,

  • patients with confirmed ARVC, but with no major RV dysfunction (RVEF >40%)
  • endurance athletes with dilated RV
  • endurance athletes with non-dilated RV
  • untrained healthy subjects with non-dilated RV

• who signed a written free and informed consent:

Exclusion Criteria:

• Patients with other cardiovascular disease;
• Contra-indication to CMR (in particular presence of a non-CMR compatible implantable cardiac defibrillator);
• Patients with permanent supraventricular arrhythmia;
• Patients unable to perform an exercise test on an ergocycle;
• Person subject to legal protection (safeguard justice, trusteeship and guardianship) and persons deprived of liberty