What Could Cause An Electrical Jolt Type Pain That Seems

What could cause an electrical jolt type pain that seems to start at the heart and project to the left upper corner of the shoulder blade - comes about every 30-45 minutes. Not affected by movement. Not overweight. Go to the gym 3 times a week. Take 25 mg atenolol 1-qam; Ranexa morning and night, amblopine besylate 5 mg 2-qam no burning or crushing pain in chest no nausea, no problem breathing, no sweating