Metoprolol

Metoprolol is a rate control drug, so it should have little effect on the arrhythmia, whatever it is, except to slow the beat rate down. This would also happen when in normal sinus rhythm. If you want to alter the rhythm because it is not NSR, then you'd take an anti-arrhythmic drug such as Flecainide, Sotalol, Multaq, propafenone, or amiodarone, just as a few examples (there are others). Naturally, this would all be done on the prescription by a qualified cardiologist or electrophysiologist.
Some people feel that their heart slows too much, and it is often demonstrated on an ECG. Some are simply getting too much metoprolol when their heart is in NSR and it slows it down into dangerous bradycardia territory, say below 40 BPM. Or, there will be long pauses evident on the ECG.
So, now is the point where I would ask you to define' gotten worse'. I'm unsure what has changed, changed from what was okay beforehand. Have any of your prescriptions changed?

Well, I have an arrhythmia.
I have taken propanolol for 30 years. I don't think it has helped, but I'm not sure without further investigation. Dr changed me to Metoprolol Extended Release. About 8 hours after taking the first Metoprolol, I had one of the worst episodes of arrhythmia ever. I went back to propanolol. None of my scripts has changed.

I take Metoprolol as needed for AFlutter. Takes about 45 mins to kick in fully and it does a wonderful job of putting things back into rhythm. No issues. Hopefully the upcoming ablation will take care of the situation and remove that need.

I am not sure what "getting worse" means, but I didn't not do well on metoprolol. Yes, it impacted my heart rate to the point that it was in the low 50s resting and only in the mid to upper 70s when I was involved in some activity. Since I am way past being an active athlete, that is too slow. I felt lethargic and I had pain and a kind of numbness in my legs below my knees. I went off of metoprolol about 2 months ago and the change/improvement was almost instantaneous. No more problems with my legs and I generally feel much better and have gone back to long walks in the morning. My heart rate is now in the mid 60s resting and in the mid 80s with activity.

It really worked for me in the ER. But as a daily thing not so much. Afib kept happening 1-2x month. I was on Diltalizan for a few years and I gained so much weight and my legs pigmented. My pcp over ruled the cardiologist who was wanting stronger drugs.
Now I’m just on Carvedilol and the weight is coming off and only 1 tiny bout with Afib 2 months ago when we did the change.

Your comments are right on! One size does not fit all! And good for you PCP for over-ruling the cardiologist if he knows your situation better and is concerned about all the Black Box warnings that come with stronger meds! I take Diltiazem since I was diagnosed with A-fib and it has worked for me--I actually lost weight. I am betting that the reason you are doing better on carvedilol is that your blood pressure is in control and losing weigh often helps the A-fib too! I think you are smart to listen to your body and not just believe another pill will solve your issues. I tried the anti-arrhythmic med for two weeks and that was it for me! Once I looked up the side effects and the warnings, I said it wasn't worth it, if it was even really doing anything anyway. I am choosing an ablation soon.

We need to advocate for ourselves now more than ever. On Diltalizan my ankles would swell so much at times, but to the world they looked fine like normal ankles. I had to insist they were swollen because I have super skinny ankles. I started carrying a picture of the skinny ankles to prove a point.
My BP has always been fine its on the lower side too. I’m on the lower dose of every drug. I’m sensitive to everything

I’ve been taking Metoprolol since 2006 to help manage my Long QT Syndrome. Other than occasional sleepiness, I don’t notice that it does much, which I guess is good. I survived 3 cardiac arrests so my cardiologist says I will need to take it for the rest of my life to help manage my heart rhythm.

Just to show how everyone is different, Metoprolol has worked wonderfully for me. I've cut my dosage from 25 mg to 12.5 mg a day, and daily baby aspirin to only one every other day. I get spontaneous palpatations almost every day, but never higher range than in the 130s BPM, and they stop spontaneously as well, or with some help from vegus maneuvers. Most last for less than 30 minutes. Oh, I'm an active 82yo male and Tai Chi instructor.

I think you are very smart; you know what works for you. I cut the dose of Flecainide by 1/2 after I began to think it was giving me side effects. My cardiologist gave me a "raft of crap" about how I needed to take as directed. That is when I looked up the drug in my drug book, saw all the Black Box warnings and decided to taper off completely. I have been fine ever since. I am not convinced it ever did anything except increase palpitations, make me feel headachy and make me constipated. I told the electrophysiologist who started the "trial" that I wouldn't take any of those toxic anti-arrhythmics and I prefer an ablation, which I finally have in the works.