Gastropericardial fistula represents a rare abnormal communication between the stomach and the pericardial sac. Flattened cardiac contour and small heart size indicate cardiac tamponade, a life-threatening condition.

In this case; it was secondary to upper GI endoscopy and biopsy of gastric fundus mass.

Other causes can include esophageal or gastric surgery or tumor, gastric ulcer or trauma.

Image courtesy of Dr. Mai Tawfeek and Dr. Fatemah Zeinhoum.