In this study the investigators aim to identify and include consecutively patients with primary aldosteronism (PA) diagnosed in the Western and Mid-parts of Norway, to describe the characteristics of these patients, to explore the cardiac effects of PA before and after specific treatment, and to identify long-term outcomes after treatment. One subgroup of the PA patients perform echocardiography to assess left ventricular systolic myocardial function before and after treatment. One subgroup of PA patients perform cardiac MRI to assess myocardial mass, myocardial fibrosis and myocardial function in rest and during stress, before and after treatment. For the cardiac MRI substudy, the PA patients are compared with a group of healthy controls, also included in the study. From 2022 onwards, PA patients diagnosed or subtyped with adrenal vein sampling at Oslo University Hospital will additionally be included in the study, thereby providing a national registration of PA patients.