Bradycardia is a slow heart beat (below 60), and symptomatic means that it is causing symptoms. So a person who has symptomatic bradycardia has a slow heart rate, and it is affecting them in a negative way.
symp·to·mat·ic (sĭm'tə-măt'ĭk, sĭmp'-) adj.
Of, relating to, or based on symptoms: symptomatic relief. Constituting a symptom, as of a disease: the rash symptomatic of scarlet fever; a rise...
According to Advanced Cardiac Life Support, atropine would be given first for symptomatic bradycardia. A person would have to be trained to give this medication.