What is the progression of a vagus nerve problem?

My husband has been diagnosed with having problems with the vagus nerve. His symtoms have been going on since mid-summer and we thought it was the heat. He was getting a dizzy feeling so that he had to sit down right away. The feeling starts at his forehead and slowly moves down his body. They said the veins in his legs would dilate and the blood rushed to his feet, blood pressure will drop and heart beat slows down dangerously - he has been told to lay down and get his feet up right away. A pacemaker is a backup and may help sometimes. This diagnose came after having a pacemaker put in that was set so if his heart rate went as low as 60 it would shock him to start the beating. After this and still having spells they did a catheterization and saw no blockage in his heart. They had already checked the arteries in his head and next before that. A test was done where he laid on a table and they put the table up for so much time, not sure what this was called. Within 30 minutes they got a reaction they said determined that it was the vagus nerve. It sounds as if there is no fix and he will just have to stop and lay down when this happens. It happens every 3-4 weeks and he started to have a second episode each time closer to the first over the last three months. It's really frustating not understanding what can happen - will it get worse and effect other areas of his body? From what I read this nerve affects your lungs, digestive system and heart. He will go for follow up next month but I am frustrated at this point just wondering what the future might hold.