Steal phenomenon


Shunting of blood away from a nervous system location causing transient or persistent ischemia or infarction. Shunting could result from hemodynamic factors causing low or reversal of arterial flow due to arterial occlusion, stenosis, hypoplasia, kinking, or compression of high-flow that leads to by-passing of local microcirculation or reduced head of pressure in other arterial branches due to arteriovenous malformations and fistulas. Hemodynamic effects are subject to modulation by posture, exercise, hemoglobin, oxygen saturation, blood pressure, and similar factors.