Pulsing sensation after root canal/crown

In October of last year, I had a retreatment of a root canal (one that had lasted probably 25 years). Everything was fine, no further pain. The crown was put on and I can now feel my pulse or heartbeat in the tooth. No pain but it feel weird. I dont think the crown fits perfectly--they had to grind it for ages to make it so it was not too high, and I can feel the sharp edge at the margin of the tooth. But no pain on biting down or anything. Why am I feeling this and should I be concerned?