Lexapro and afib

I have a serotonin receptor genetic variant (5HT2C) along with a MTHFR genetic variant. For years I've self medicated with 1/3 of a 500 mg L-Tryptophan capule at night to increase my serotonin levels, with pleasing results. Last month I noticed it seemed to bother my heart so I stopped it. I realize that serotonin has many effects in the body, so don't want to play around with this. But I miss having healthy serotonin levels. Does anyone have experience with SSRI's in regards to their heart health?

I did ask my EP office (the NP for a visit last month) because I was considering starting. She said SSRIs can be a trigger. She's just one person but is part of the EP group.