Back in 2005, my BP got as low as 80/50, and my pulse had slowed to 50.
I went to see three different cardiologists, and had all of the tests done. They found nothing wrong, and could give me no reason for this. One or the cardiologists actually prescribed a antidepressant! The third one put me on medication to raise my BP, which helped some.
After being on the medication for a couple of years, I took Valcyte for 8 months. During that time, I was able to wean myself off the medication. Once I stopped the Valcyte, my BP had risen to an average of 110/66.
The cause of my low BP was most likely Viral. I have tested positive for HHV6, CMV, EBV, and VZV, so one or more may have been involved. Since I stopped the Valcyte in late 2008, my BP has remained stable.
I did some reading about Viruses and the heart back when this was happening to me. I seem to remember that Drs. Peckerman and Natelson had done some research on this subject.
John