This was a key reason why I changed my mind about valve type. As you know, I was originally planning to go tissue, but then switched to mechanical. I kept thinking how difficult it is to get those echos every 6 months and to always get bad news- things have become a little (or a lot) worse. If I went tissue, at some point, probably after 7-9 years, I would be told that SVD has started and we better start upping the frequency of the echos and watch it closely. Whereas with mechanical valves, apparently, what is more common is to be told that things have looked the same for so long that you need less frequent echos. I'd much rather be getting that news.you have to make decisions about not just yourself, but about yourself in 10 years, yourself in 20 years .