I am currently dealing with a very similar situation. I have lyme, POTs, and another heart arrythmia ( idiopathic VT) that was diagnosed in March. In March, cardiologist put me on a beta blocker.l for the arrythmia. For the next few weeks, it worked well. Then I started having breakthrough Tachycardia, heart rate going up to 150 but in sinus rhythm (Id previously never had rates that high before). Cardio said to increase the beta blocker ( metoprolol). I did and that kept the Tachycardia and arrythmia away for 6-7 months. I thought it was really well managed, although the bb made me feel awful almost all the time). Well, last Friday, my heart rate went up to 160 when I was getting dressed. Had to call 911, paramedics said it was sinus Tachycardia. POTs had been acting crazy all week, where my heart rate would increase 20+ points from a slight movement in bed, 30-40 points when sitting to standing. This is very atypical for me, and a very drastic increase in POTS. Followed up with cardio he said to get back on Florinef, increase salt and fluids. I have been hydrating like craxy, taking salt stick capsules, past 4 -5 days, and still having episodes of Tachycardia. Last night, I was sitting on couch talking on phone, and heart went to 150, and I felt horrible. I was sure I was going into an episode of ventricular tachycardia. Called 911, barely made it downstairs to meet them. HR was 150 with them, but sinus. I insisted onER Bc i wanted to get to the bottom of this. ER was useless, the gave me fluids, but didn't notice any difference. My HR never went down below 100. ( my normal reasting Hr on the bb is 60-75). I am starting to wonder if I now have SVT in addition to POTs and idiopathic VT. I have NO idea how I am going to manage this, and am beyond stressed. I can't have my heart going up to 150-160 every day or other day. I have no idea what's cause this sudden increase in symptoms or why the beta blocker has appparently totally stopped working. I feel your pain so much. The ER was like "you're complicated". really? I also have had high BP and the higher lower number like you. I know cardio will want to increase bb. I don't know how I'll possibly tolerate it! I think it seems we both have hyper POTS. It seems like we are having way too much adrenaline. I have no idea waht we can do!!! If you want my contact info to stay in touch lmk! I'd really like a buddy with this! It's horrendous!!!!!!!! I have NO CLUE how to handle/ manage multiple heart conditions. This is very disabling for me. One other question - at what point or HR do you call ER? I'm starting to think I'm just gonna have to live with this... I can't be going to ER every day.