My 21 Year Old Son Had The Procedure For WPW

My 21 year old son had the procedure for WPW but since the electrical pulses were not originating in the heart, there was nothing to "zap" to fix it. He was feeling as if his heart was stopping and starting up again, which is why we took him to the doctor in the first place. We were told that his heart is fine, but to keep a copy of his EKG since his heartbeat will always be irregular. Lately, he has been having severe night sweats and during the day his underarms sweat profusely. I have been reading where all of this can be linked to cardiac problems as well as hormonal problems. I have a feeling the irregular heartbeat and hormonal issues are linked. What could this be related to?