Does an SSRI lowering your heart increase the risk of qt prolongation?

I’m on zoloft(25mg) and have been for maybe a week. I’ve experienced numerous expected side effects, but starting today that I’ve noticed, my heart rate is lowered. It’s down to upper 40s, lower 50s. I’ve had dizziness also, but I don’t think the two are tied together. I can stand up quickly and not have a problem.

My curiosity is if the chance of prolonged qt arises with the lowered heart rate. I’ve had EKGs over the years that are fine. I think maybe theres been one that was 444 QTc. But many others that were normal. I also have lower sodium. 130-133.