Vagal pseudohemorrhage after percutaneous biopsy.

Vagal reaction occurring after percutaneous needle biopsy can mimic hypovolemic shock. Misdiagnosis has led to unnecessary surgery and death. Both vagal reaction and hypovolemia can produce hypotension, pallor, and diaphoresis. Vagal reaction is characterized by bradycardia or absence of tachycardia. On the other hand, hypovolemia is characterized by tachycardia. Atropine in large doses is the treatment of choice for vagal reaction, when treatment is necessary. Radiologists involved in percutaneous biopsy procedures should be aware of vagal reactions and should known how to treat them.