How long should i wait before going to hospital with palpitations?

Depends: Most palpitations are benign so if you are young and do not have other symptoms, it is probably not an emergency. If you are older and are having chest pain or trouble breathing, or passing out, then you better get help sooner rather than later.

It depends: If they are associated with chest pain, dizziness, shortness of breath, passing out, you should call 911 and go now. Otherwise, follow with your physician soon to get evaluated. Some palpitations may be benign of no consequence while some could be a sign of serious arrhythmia.