Classification of Rare Cardiovascular Diseases anticoagulation atrial fibrillation atrial septal defect cardiomyopathy computed tomography congenital heart disease echocardiography electrocardiogram electrocardiography heart failure implantable cardioverter‑defibrillator magnetic resonance imaging pregnancy pulmonary arterial hypertension pulmonary hypertension rare cardiovascular disease rare disease right heart catheterization right ventricular failure