[Follow-up of familial idiopathic dilatation of the right atrium].

In 1979 the diagnosis of idiopathic enlargment of the right atrium had been made in four members of a family, living in the northeastern part of Switzerland. A 5-year follow-up study of these four patients by ECG, chest X-ray, bicycle-ergometry and echocardiography showed a variable evolution: One of the two patients with the originally largest atria, showed further massive enlargement of the right atrium, combined with tricuspid insufficiency. One presented unchanged echo findings. In the other two patients with originally smaller atria a discrepancy of the course was also observed: in one right atrial size increased considerably (with appearance of atrial flutter), in the other patient the size of the atrium remained unchanged. In both patients a pericardial effusion occurred. Subjective symptoms and physical working capacity did not change in the four patients.