Clinical manifestation and survival of patients with idiopathic bilateral atrial dilatation

We studied the histories of eight patients who lacked clear evidence of car diac abnormalities other than marked bilateral atrial dilatation and atrial fibrillation, which have rarely been discussed in the literature, From the time of their first visit to our hospital, the patients' chest radiographs and electrocardiograms showed markedly enlarged cardiac silhouettes and at rial fibrillation, respectively, Each patient's echocardiogram showed a mar ked bilateral atrial dilatation with almost normal wall motion of both vent ricles, In one patient, inflammatory change was demonstrated by cardiac cat heterization and endomyocardial biopsy from the right ventricle, Seven of o ur eight cases were elderly women, Over a long period after the diagnosis o f cardiomegaly or arrhythmia, diuretics or digitalis offered good results i n the treatment of edema and congestion in these patients. In view of the c linical courses included in the present study, we conclude that this disord er has a good prognosis.