Thanks very much to everyone who's commented and emailed. The cardiac cath dept. at our local hospital is "down" today (some kind of computer thing from what I gather) so they've postponed John's test until tomorrow....We're finding that "hurry up and wait" is standard operating procedure, but everyone has been so nice we really can't complain. John is comfortable, if a bit frustrated with everything still up in the air.
We should know more tomorrow. In the meantime, he's breathing easier and they've managed to slow his heart rate - a good thing. :)