Brief Answer:
Follow up / may need further investigations

Detailed Answer:
Dear friend,
Welcome to Health Care Magic

Heart rate of 60 or less is called bradycardia.
So is 1st degree block – prolongation of PR interval, beyond a statistical limit…
There are individual variations and it is not always abnormal… especially in asymptomatic individuals with normal examination and ECHO…

     HOLTER (24 to 48 hour ambulatory monitoring) is generally done to analyse and plan for further management…It may also detect silent (no symptom) ischemia.
     ECHOcardiogram is necessary to see the heart valves (Mitral Valve Prolapse) / heart muscle (Cardiomyopathy) and heart function (Ejection fraction, wall motion abnormality) / clots...
      TMT – Treadmill exercise ECG; may be with thallium isotope – is necessary to exclude ischemia (reduced blood flow / Coronary Artery Disease)

      If you also have symptoms like blurred vision, dizziness, loss of consciousness, shortness of breath, chest pain along with this, you need urgent work up… else observation and follow up is all that us needed…. I is likely to be degenerative disease of the conduction system and if so, ultimately, one may need a pacemaker…
     If there are no clues and if the problem is still bothering to the extent of interfering with life style, there are advanced techniques of investigations of increasing complexity – Electro Physiological Studies (EPS) > it resembles angio – a catheter is put inside the heart / electrical activity recorded / stimulation and suppression tests are carried out and so on… Though the test is the gold standard, it is INVASIVE and hence is not generally done unless there are compelling indications. This super-speciality expert is called ELECTRO-PHYSIOLOGIST.

There are no drugs, life style changes or nutritional supplements...
The treating doctor may suggest further depending on need, based on his assessment of the situation.
Keep following up

Take care
Good luck

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