79 year old female with a 5 year history of stroke symptons on the right side.now has a pain under the right arm at the chest breast area. Sharp pain comes and goes and has been this was for the last 18 hours. This female has a history of spinal stenois (since birth) and now...due to age...is bodly shrinking from 5'2" to 5'...causing more problems beside the major stroke she suffered. ..What would cause this sharp pain???