Suclavian steal left
There are a number of reasons for your symptoms, but one that
could acount for both is blockage of the left suclavian artery which
supplies blood to the left arm. Dependin on the location of the blockage, the vertebral-basilar artery may draw some blood away from the brain to the left arm leading to faintness.
Your doctor should check for differences in pulse and blood pressures in both arms.