Inclusion Criteria:  Controls:  Aged 18 and more Have had an echocardiogram within 6 months prior to inclusion Have had a cardiac Holter in the 6 months prior to inclusion. Informed Consent given  Cases :  Aged 18 and over Presence of cardiac amyloidosis with Transthyretin Have had an echocardiogram within 6 months prior to inclusion Have had a cardiac Holter monitoring in the 6 months prior to inclusion. Informed Consent given  Exclusion Criteria:  Controls  Known case of amyloidosis in the immediate family Patient known to have amyloidosis Left ventricular wall thickness greater than or equal to 14 mm Hyperechogenicity of the left ventricular walls Cardiac disease which may affect electro-anatomic mapping: Right ventricular dysplasia, myocardial infarction, congenital heart disease. Contraindication such as pregnancy to radiological exams Presence of an anomaly of the vena cava Presence of intracavitary thrombus at cardiac echocardiography Patients with a pacemaker  Cases  Cardiac disease which may affect electro-anatomic mapping: Right ventricular dysplasia, myocardial infarction, congenital heart disease. Contraindication such as pregnancy to radiological exams Presence of an anomaly of the vena cava Presence of intracavitary thrombus at cardiac echocardiography