Ellie, Hang in there! I'm sure you're disappointed that surgery had to be postponed... but tis better to check you out BEFORE the knee surgery. When I had an echo done two years ago, there was an area that couldnt be seen clearly (something was questionable) so a cath was recommeneded. I had cath done and was relieved when nothing wrong was found. It relieved my poor liddle mind. Hope there's nothing wrong with you. Hope you and the furbabies are doing good. ((Hugs)) Kay