Final answer:
The cause of symptomatic arteriovenous fistula is typically related to trauma or injury that results in an abnormal connection between an artery and vein.
Step-by-step explanation:
The cause of symptomatic arteriovenous fistula is typically due to trauma or injury. While not directly referenced in the provided information, this understanding comes from the fact that arteriovenous fistulas can form when an artery and vein are damaged, and the healing process connects the two abnormal vessels. This connection allows blood to flow directly from the high-pressure arterial system to the lower-pressure venous system, bypassing the capillary bed which can lead to a variety of symptoms. On the other hand, the information provided references congenital conditions such as patent ductus arteriosus and coarctation of the aorta, which are structural abnormalities present from birth, rather than acquired conditions like arteriovenous fistulas typically due to injury.