I forgot most of what I knew about
Houttuynia, but if you're treating bartonella, I can tell you that my experience has been that any time I've treated bartonella I get heart palpitations etc.
Also if I recall correctly Houttuynia increases nitric oxide in the blood, so that's another thing to keep in mind.
Here's a study on that:
https://www.ncbi.nlm.nih.gov/pubmed/25923355