Patrish, sorry you have not been successful with the Toprol. I also have Lone Afib and was first prescribed Bisoprolol, a beta blocker with no anti-arrhythmic properties. It didn't work and I had two episodes of afib while taking this drug. It controlled the tachy but did not prevent the afib. I was then switched to Sotalol. It has held me now for over 2 months with only one 7 hour afib episode, caused, I think, by over-tiredness and de-hydration after working outside all day in the heat. So, my verdict on Sotalol is positive and I would definitely give it a try if your cardiologist is recommending it. As for the risk of dangerous V-fib, my understanding is that the risk is low with this drug but, because of it, Sotalol is usually started in the hospital, at least in the US. Patients are monitored for any dangerous heart rhythms for 3 days. For some reason, this isn't done in Canada where I live. I was simply given the prescription and sent home to start the drug. I suffered no ill effects other than the predictable side effects of beta and channel blockers which are abating as my body has learned to tolerate the drug.
As for being tired all the time, that is definitely one of the symptoms of afib, at least for me. It is very debilitating. Fatigue is also a possible side effect of beta blockers of all types so it could be caused by the Toprol. Again, I have adjusted to the Sotalol as my body has re-gained strength by being in normal rhythm for 2 months. Normal rhythm trumps the side effects of the drug, at least in my experience.
You might ask your doctor about a higher dosage of Toprol. I take 100 mg XL twice a day. It might make a difference.
I am surprised that your doctor has not upped the dosage of toprol. You are taking a low dose. I was on toprol for alittle while, and it did help me. I was also on Sotalol for a few years (combined with Cardizem) and that helped me also. In regard to V-fib and sotalol, I really haven't heard of that. I have heard of v-tach a very low possibality when on sotalol, but not v-fib. I would recommend you trying the sotalol. When I was first put on it, I was monitored in the hospital for 3 days. I had no reaction to it. Yes, it did make me tired, but I got use to it. Good Luck! Wishing you well, and wishing you enough...
As I understand it, Sotalol carries a small risk of causing Torsades de pointes, a dangerous form of V-Tach which can de-generate into VFib, a potentially fatal arrhythmia. This is very low risk and the drug is not prescribed for patients who exhibit known risk factors. Patrish1, I would not let this discourage you from trying Sotalol if your cardiologist has recommended it.