[Arteriovenous fistula of the blood vessels of the neck--a rare differential diagnosis of venous hum in childhood].

In a case report it is shown that in rare circumstances there might be an extracardial organic cause for heart murmurs sounding accidentally. In a child with the finding of a venous hum an arterio-venous fistula between the right common carotid artery and the right internal jugular vein could be demonstrated by colour-coded echocardiography. The clinical relevance of this finding is discussed.