Suggestions for failed cardioversion and meds?

I have been on/off this forum for about 20 years. I am now 74. Have genetic afib (mother, two brothers) . Mine is paroxysmal and I always know when it starts. Had one ablation in 2007. Went two years no afib, then the episodes slowly started back a few a year. Have successfully used pill-in-the-pocket approach for 13 years to keep them at bay (lorazepam, Xarelto, 250 mg. flec). In between like a normal person. Because my resting heart-rate went up (to low 90s) after the ablation I have been taking Bisoprolol (5mg. am; 21/2mg pm) This has worked like a dream. About three years ago I was sometimes no longer able to stop the episodes with the meds and had electro cardioversions (3 last year).
The other issue that has arisen in the last few years is more flutter. It was determined to be atypical atrial flutter in that it starts in the scar tissue of the ablation. Nowadays I get flutter more often than fib or sometimes they seem to alternate during the same episode; and more difficult to get rid of.

I have absolutely no "triggers" for afib and episodes usually start in the middle of the night or when resting. Drink coffee, wine, eat chocolate, kimchee, whatever. Go to vigorous cardio classes.

Two days ago I woke up in flutter. Definite flutter, no irregular heartbeats; pulse hovered around 128. Took my normal meds and carried on. No relief. If the meds work, they usually do in 2, 6, 12 hrs. This time no. As it happens I had a previously scheduled appointment with my cardiologist the next day so I thought that I'd see him and them walk across the street to the hospital for a cardioversion. He, confirmed flutter; told me to go home and take more flec. [I balked at that because flec is so toxic and a few years ago I am sure I had "flec poisoning" because unknowingly I kept taking higher doses; the episode ended up lasting for a week at that time]. He also said that because I have a "healthy heart, 128 beast is nothing urgent to worry about" (his words).

Anyway, went home. Had had nothing to eat for almost 10 hrs. waiting for the cardioversion; missed the bus and walked 15 min. home.
About half hour later I suddenly got dizzy, weak, sweated profusely; unable to even sit in a chair had to lie down. I really thought I was having a heart attack so called the ambulance.
Fortunately no heart attack. Maybe due to the external factors. So I was prepped for a cardioversion. Well, for the first time for me it did not work. Apparently they tried twice. I think the ER people were experienced. I could tell from their questions. There was no cardiologist on duty (???) so in consulting with an internal medicine specialist they decided to try conversion with meds. First Metroprolol. Did not work. Then Diltiazem. My heartrate came down to acceptable low 70s and so I was sent home. With the advice that I should change from Bisoprolol to Diltiazem.

Now it is the next morning: feel dizzy on getting out of bed. I took my blood pressure (rather low 100/65) and heartrate - 135. So nothing has changed.
I am now completely puzzled.
Should I take the meds again. I have already taken Xarelto and Bisoprolol. Scared to take more than 50 mg. Flec.
Should I contact the Afib Clinic at Vancouver General Hospital ( have already been assessed by them for touch-up ablation about five years ago but did not go). Don't want to go back to the same ER as I was last night because I don't know which doctors are on duty. There is one who knows me from previous cardioversions and he is good. And let them try again?

I am a little on the fence about Diltiazem. Does anybody have any experience? I hate to change from a med that is not causing any side effects.
And obviously what they gave me intravenously has had no lasting effect at all (only about 8 hrs.).
Felt again dizzy on getting up (low blood pressure?) but after two cups of coffee, feel half-human. No dizziness.

Any insight? Suggestions?
Thanks,
Ritva

I would do as they suggested. Stop the bisoprolol and start the diltiazem. Diltiazem is a really benign drug and there's no reason to be afraid of it.

Ritva- how much do you weigh? Flecainide dose is no more than 200mg (thanksxGeirgeN) if you weigh less than 152.

I was in the cardiac icu for three days due to flecainide overdose. I listened to the wrong EP and took 300mg/day. at the time I weighed 122. So be careful with flecainide. It’s a black label drug (can cause sudden death).

See if you can get a flecainide serum test. They draw blood 11 hours exactly after your last dose.

Thank you both.
I have an EP who said I can take up to 300 mg. of flec as I weight about 160 lbs. For the past few years I've only had to take it on an average every 3-4 months. Usually episodes go away with one dose. I also read that it takes 4 days for flec to "wash" out of your systems so do not take them continuously. At the time of suspected poisoning I was not aware that FDA had "black boxed" flec. Now I am more careful.

As for diltiazem - there is a lengthy article on Drugs.com about warning that women especially taking CCBs (like diltiazem) are at great risk of developing pancreatic cancer. So will hold off on that. Bisoprolol is on the other hand linked to cholesterol. We can't win. Will discuss further with my Cardiologist but continue on a slightly increased dose of Bisoprolol for now.

Need to get my flutter ablated as it now seems to become more persistent.

Thanks