Stress, what stress?

Hubby went in for a physical 10 days ago. On that day his heart rate, pulse, everything were within normal limits. He got sick last weekend with one of the stomach bugs the kids like to bring home from school and share. Wednesday, he was still having problems eating anything, so he went to the doctor. His blood pressure was 180 over 90 (I think I have the bottom number correct, I know he said the top was 180.). The doctor has no idea why the top of his heart is beating twice as fast as it should, he could hear it with the stethescope during the exam. So Hubby is now on blood thinners, with a 2 day stress test scheduled for Tuesday and Wednesday, and a visit to the Cardiologist the week after. The doctor must have been worried, as he immediately arranged for the tests and cardiologist visit, making other patients wait. Of course, he also said that sometimes, if they stop the heart, when they restart it the beat goes back to normal? Does not sound like fun...