Rare Bradycardia or what?

[Luthfi_Eka]

My age is 15, a few years ago i started to feel chest pain continuously whenever i start running or do any hard physical activities, one time i realized my chest was pounding very slow so i used a Cardio meter app from my phone. Till now whenever im resting my body, it mostly beats below 60 per minute. This usually happens when im sitting or laying. I am not a smoker but sometimes i do accidentally inhale my uncle’s smoke when im with him.  I do a balanced diet, my body is fit: 165cm in height and 45kg in weight. But i dont know till now what im suffering from. Any solutions?