Contact your general physician, and he'll go from there. I suggest you do it rather quickly. Have you considered you may have an aneurism?
Hi MedGk, as suggested by tacolino it is better to go to your doctor, especially if it concerns your heart and breathing. If you don't have a doctor, go to the nearest hospital or clinic so they can run some tests if necessary.
When it comes to the heart, you go to a cardiologist. If it's your breathing, you go to a pulmonologist. But again, make sure you get yourself diagnosed first.
Hope this helps.
Best to go yo your family doctor fairly promptly, to check this out.
It may be nothing, but best be cautious.
An ecg, blood and bp tests and a physical exam are warranted.
Is the pain on exertion or at rest?
Do you have any medical issues?
How are your bp numbers?
If it gets worse before the appt with your doc, go to the ER to be safe