Spontaneous intramural left atrial hematoma associated with systemic amyloidosis.

Spontaneous intramural left atrial hematoma is very rare. We describe a case of spontaneous intramural left atrial hematoma that had to be semiurgently resected. Postoperatively, the patient was diagnosed as having systemic immunocyte-derived (AL) amyloidosis, because of rare manifestations of fatal bleeding. Though spontaneous intramural left atrial hematoma is one of the severe complications of systemic AL amyloidosis, we believe that amyloid deposits caused fragility of the left atrial wall.