Is the vibration more systemic, through your shoulders and upper arms or is it centered only in your heart ares?
I hear people describe different arythmias as a vibration. I know one person described a-fib like that. Obviously theres no way to know without it being captured on a holter. If you get it daily, a 24 hour holter should be fine but if its rare, a 30 day event recorder would be needed. You need to see a cardioloigist to be safe. If its afib you would need to be on some sort of blood thinner. Please call your cardiologist. Another thing to consider is calling a pharmacist or researching to see if the medication you are on can cause any heart rythm issues.