After going into the problem as has been described by you, the problem does not appear to be of cardiac origin. It is surely what is known as a 'Panic Disorder. She needs a comprehensive reassurance & should be assured that the problem is going to be solved definitely & she is required to keep her morale high, which will be possible only if she gets relief with consultation of a psychiatrist
& this will boost her confidence. She would require to continue the treatment for a long time with a careful & gradual reduction of her anxiolytics & antidepressants, preferably citalopram
& a SSRI
or preferably a tricyclic antidepressant
. A concomitant cognitive behavioral treatment is also recommended.