Dropping blood pressure during AFib

Appreciated your responses to earlier questions. Healthy at 61, put on Atenolol (took it late at night) and aspirin after MD was able to catch daytime Afib on an event  monitor 10/07.
     History: A January dinner had 2 glasses of wine…. then before and during sleep that night AFib came along with frequent urination and dropping BP 85/55 and higher pulse (95) instead of usual 135/80 and usual 50 heart rate.. 6 AM fainted as I stood up from sitting at kitchen table. After feignt I had converted. Dr said because I had conversion HB pause, because maybe the need for stronger drugs and because of my non-medicated lowish Heart rate that a  pacemaker was in order.
      Since getting Pacemaker (1/16/08) I stopped running/exercising vigorously (130-40 HB), started sleeping/relaxing more and walking (80-100HB). Switched from Atenolol at night  to  Metoprolol noon time (and Coumidin). No longer anxious and feeling better.
            The 4-5 Afib episodes over past 4 months (since January) all occurred at night---usually around 1 AM with frequent urination and dropping BP. Most have occurred after 1 beer or 1 glass of wine (I have stopped drinking), and one after 2 non-alcoholic beers. After early morning conversion, the low BP starts to work its way back up t0 135/80. No fainting when I convert, but also I don’t believe pacemaker has as yet needed to kick in (so thospital tech told me)
            From reading Afibbers.com, I guess the nighttime Afib is Vagal type LONE LFA.
I read frequent urination is typical (now I try to drink some water to offset H20 loss)but what about the dropping blood pressure rate? When I had some daytime Afib awhile back, was this Adrenergic type LFA. Is just the Adrenergic likely to be progressive?  Why do I now (so far) only get Afib in the middle of the night?                                                        

          

[Michael J. McWilliams, M.D.]

Lone AF is when you have atrial fibrillation and no other medical problems.

Some people drop their blood pressure during atrial fibrillation.  One potential mechanism is the loss of atrial based ventricular filling -- the atrial kick is lost during atrial fibrillation.  50 mmHg is a lot to drop for just atrial fibrillation.  It would important for someone like yourself to get out of bed very slowly at night to make sure you don't pass out.

Vagal AF can happen during the day.  Typically during a meal or drink, especially if it is cold.  Just because it is daytime does not mean that it is adrenergic atrial fibrillation.  The reason you get it at night might be because it is vagal atrial fibrillation.

Non vagal atrial fibrillation ( I really want to call it adrenergic AF) is probably more progressive than vagal atrial fibrillation, but this is pure speculation.  I have never read that before.

I hope this helps.