Thanks to all
I just want to say thank you to everyone who has contributed to this thread. When I started it, I didn't think that it would grow as it has, nor did I think that it would last this long. My original intent was simply to try and explain some nuances about AVRT so that people might get up to speed on it faster than I did. However, many of the questions that people have posed on here have invariably forced me to re-evaluate AVRT on a deeper level. I suppose Frank Oppenheimer was correct when he said that the best way to learn is to teach. I would add that the best way to teach is to keep learning.