female 74 years old, diagnosed with a-fib july 2013 , pacemaker implanted in November 2013, meds, xarelto,toprol xl lanoxin ///severe chest pains above pacemaker feb 2014 called 911,to emergency room, kept overnite, no stroke,no heart attack. released to home . severe chest pains tonite3/23/2014 ,9:30 pm. 20 or 30 seconds and gone . WHAT IS CAUSING THE SEVERE PAINS???