An autopsy case of familial idiopathic dilatation of bilateral atria.

A 59-year-old male patient was followed up for congestive heart failure. Echo cardiogram showed no abnormal findings other than a remarkable dilatation of the bilateral atria. The coronary arteries and left ventricular contraction were normal. Left ventricular endomyocardial biopsy showed no significant abnormal findings. Further, we examined his siblings using dynamic magnetic resonance imaging (MRI) and found that they all also had dilated bilateral atria. After several hospitalizations, the proband died from cardiogenic shock. Pathological findings showed nonspecific change in bilateral atria and ventricles. This is a very rare case of familial idiopathic dilatation of bilateral atria.