Hi, it's been a while since your post... how are you doing and did you get a diagnosis? This is a symptom that should be checked out by a doctor. It's called pulsatile tinnitus and has many possible causes. Some causes are difficult to find and treat, but don't give up! Do an online search for "whooshers" for more information. Also, there are tips there from other "whooshers" about how to deal with the annoying heartbeat sound. Good luck
Did you read my posting on the same condition - heartbeats in my left ear, by carambola?
I was referred to a ear specialist - did not find anything wrong inside the ear nor brain tumor which they suspected.
But you should have it looked at, at least get a referral to a ear specialist from your primary doctor.
Go get examined by your doctor, it could be fluid buildup in the ear, serous otitis media (otitis media with effusion) which comes from a blocked eustachian tube.