[Two cases of idiopathic pneumopericardium].

Idiopathic pneumopericardium (I.P.) is a rare disease which occurs in a manner etiologically different from pneumopericardium. Recently, we encountered two apparent cases of I.P. at the Department of Surgery, Aomori Rhosai Hospital. Results of observation indicated that, in case 1, diving practice in a pool was the cause of the sickness, and in case 2, the cause was severe morning sickness during pregnancy. Unlike pneumopericardium that comes from traumatism, lesions of the surrounding organs, infection iatrogenicity and the like, the present cases were diagnosed as idiopathic pneumopericardium resulting from rupture of a number of alveoli due to transitory abnormal increase in Valsalva maneuver at expiration.