Normal heart rate of 45 - given beta blocker for afib?

My sister is 75 and in excellent health had an afib attack recently which she thinks was caused by amlodiprine (sp). which is listed as a side effect. Her doctor has prescribed 50 mgs of Toprol which has lowered her pulse at times to 30. She feels awful and has palpitations. She complained to the doctor and he has increased the Toprol to 75 mgs. She and I are worried that her heart rate will go dangerously low. Anyone have experience with a low normal heart rate and had to take beta blockers to try to prevent another Afib attack?

When my HR went to 40 being on a beta blocker i decided to stop taking them (not advising you to do the same because the doctor surely knows more about your sister's situation)
Also wonder what other afibbers experienced

My understanding is that beta blockers don't really prevent afib. In the afib world, BB's are a rate control drug. If someone has a high afib heart rate, then BB's are indicated, at least during afib. Also, sometimes a high heart rate during exertion can trigger afib and a BB can help prevent this from happening. If she was getting palpitations at 30 BPM, I'm not a doc, but I don't think a higher dose makes sense.

What was her rate during the AF episode? How long was the episode? That’s what I would use to decide on the BB. If it was short (< 1 day) or the rate was under 100 bpm then I would argue with the docs about the BB. Or push for a pill in pocket approach if she’s easily able to tell if she is in AF or not.

Also I hope she’s not paying top dollar for Toprol, which is the brand name for the generic drug metoprolol. It’s should only cost a few dollars (like 2 or 3) for a bottle.

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Joyce222
My sister is 75 and in excellent health had an afib attack recently which she thinks was caused by amlodiprine (sp). which is listed as a side effect. Her doctor has prescribed 50 mgs of Toprol which has lowered her pulse at times to 30. She feels awful and has palpitations. She complained to the doctor and he has increased the Toprol to 75 mgs. She and I are worried that her heart rate will go dangerously low. Anyone have experience with a low normal heart rate and had to take beta blockers to try to prevent another Afib attack?

The amlodipine didn't cause her afib but that's beside the point. I'm no doctor but raising her dosage from 50 mg to 75 mg with a heart rate dropping into the 30s is wrong, wrong, wrong. Of course she feels awful. She's probably in afib, which feels bad enough all on its own, but with the dose of beta blocker she's taking I bet she feels like absolute crap. If I were her I would stop taking that increased dose immediately. It is dangerous, as you suspect.

What sort of doctor is prescribing for her? I'm guessing it's either a general cardiologist or a PCP. She needs to find an electrophysiologist (EP) as soon as possible. An EP is a cardiologist who specializes in abnormal heart rhythms and that's who she should be seeing. No way would a competent EP write that prescription for her. Just be aware it may take a while to get in to see an EP.

As George said, the Toprol doesn't prevent afib; it just slows her heart rate while she's in afib. While that's important in the long run, it's not crucial in the short run. And wolfpack is also right about Toprol. I hope she's been prescribed generic metoprolol and if not she should ask the pharmacist to substitute the generic. It's dirt cheap.

I've got to agree with Carey on this one. Thirty beats per minute may be okay in a young athlete, but not a 75 year old. In fact, I think it is dangerous. You may want to consider asking a cardiologist or electrophysiologist about a pacemaker for her.
My father had thirty beats per minute at 90 years old. They put a pacemaker in the next day and that was a Sunday.
I think you should treat this situation as URGENT.

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Jim Benton
I've got to agree with Carey on this one. Thirty beats per minute may be okay in a young athlete, but not a 75 year old. In fact, I think it is dangerous. You may want to consider asking a cardiologist or electrophysiologist about a pacemaker for her.
My father had thirty beats per minute at 90 years old. They put a pacemaker in the next day and that was a Sunday.
I think you should treat this situation as URGENT.

Jim, the Toprol is driving her heart rate to 30. Take away the exogenous med and she's not at 30, but at 45. I don't think pacer is called for. She just needs someone, as Carey says, who knows what they are doing in the script department.

I agree with the others, and I would see another Dr. ASAP. The way I read your Post, your sister is back in NSR? If her normal NSR HR is indeed 45, then why is she even taking a Beta-Blocker to begin with? Is she still on the Amlodipine? That is a Calcium Channel Blocker, and depending on the person, it can lower HR as well. Also do you know if your Sisters AFIB is Adrenergic or Vagally mediated? If she has Vagal AFIB, then Beta Blockers can make AFIB more likely.

From the Following: Study [academic.oup.com]
"Autonomic influences should be taken into consideration since non-recommended treatment may result in aggravation of vagal AF."

Joyce — Truly baffling post!

Please let us know how this goes for your sis.

All the best.

/L