Subclavian steal syndrome. A report of two cases.

Two cases of subclavian steal syndrome are reported. Symptoms included light-headedness or syncope, reflecting vertebrobasilar insufficiency, and in one case, numbness and tingling in the left upper extremity, reflecting ischemia. Many persons with this syndrome are asymptomatic. Key findings include unilaterally decreased pulses and a significant difference in blood pressure between the upper extremities. Arch aortography, the "gold standard" of diagnosis, must be performed before surgical intervention.