I always thought those signs were to protect the amusement parks in litigation CRAZY America. However, when my rhythms had reached a point where it didn't take too much to trigger it, I was just driving on a bumpy road and lost my rhythm stability. I think it depends on how frequently it happens and what your triggers are.
I always wondered the same thing when I had SVT. (I had an ablation done in Aug. and haven't had SVT since.) My thinking was that if the ride was scary or too fast , it might trigger the SVT. I used to think that the fast and sudden motion or laughing or screaming could also set it off. I always avoided rides that said if you have a heart condition it might not be good because I was so scared it could trigger the SVT and I didn't want to have to deal with it while I was in Disney world.
Why don't you ask your Dr. what he thinks? Most likely, the rides won't be any problem but it will make you feel better once you talk with him.
Betty
I am not positive, but I think those precautions are more for people with CHF and more serious problems, maybe surgical patients....I would imagine if you were having frequent episodes of SVT you might want to avoid those particular rides.
In my case, the rides would set off PVCs, almost always. Probably a combination of the force and the stress/anxiety/adrenalin.
Have a great trip! I love WDW!