From the story of you've given, it's unlikely that there is anything serious going on here.
Definately worth having a chat with the quack, who is likely to ask about the frequency and duration if your symptoms, your descriptions of the heart rythm,and the link between the pounding in your chest and any other symptoms, (breathlessness, feinting etc.)
I expect that the cold tingly feelings are co-incidental, and 84 BPM isn't an indication of disease.
He'll probably have a quick listen to your ticker, listen to your blood pressure, and he may refer you for other tests. (or he may not, depending on his initial findings.)
Further tests may include blood tests, (looking for any chemical resons for your symptoms), and ECG, (electrical tracing of the heart), or a 24 hour ECG. (Looking at the tracing over 24hrs.)
I suspect at the end of all this, he will give you some reassurance and advice about lifestyle.
Not one for the internet at this stage, go and see the quack, and keep us informed.
