First of all when the heart rate is 58 beats/minute you should clarify what the usual heart rate is. If the usual heart rate is 80 beats or more and suddenly drops to 58 beats/minute, it may be related to the disease or medication causing the bradycardia, at which point the patient is mostly symptomatic and should be seen promptly. If the heart rate is normally 58 beats per minute and there are no symptoms associated with bradycardia, there is no need to be alarmed as this is a normal physiological state and should be followed up and observed.