The vet just called. It was only a short call because there wasn't much to say, but it appears that over the last few ours his condition has stayed pretty much the same. He is no better, but at least he has not gone any further down hill. I don't think he can actually get any worse. But they have given him a drug to help with his blood pressure (I don't know what) and that has apparently had a positive effect on his heart and is blood pressure is up slightly. Fingers crossed that he will start to get stronger. They are going to call me again in a couple of hours...