Vagal AF

[EngMac]

I thought I would start a new thread since sometimes I miss info in older threads, and others will do the same, especially if they have not posted anything on the older thread.

I saw the following in a 2007 study and found it helpful. If this information is true, it is hard to understand why an EP or cardiologist would not want to positively identify the type of AF the patient has before beginning any treatment. Maybe they do and I just got misdiagnosed.

Excerpts from a study done in 2007 (Remember this is a 2007 study. Much has happened with drugs since then. )

Adrenergic-mediated AF

Less common

No particular predominance

Often in patients with identified heart disease

During daytime or diurnal (daily cycle), provoked by exercise or emotional stress

Preceded by tachycardia

Higher ventricular response rate during AF

Benefit from beta blocker and/or digoxin

Vagal-mediated AF

More common

Predominantly in men, age between 30 and 50 years

Patients without heart disease (lone AF)

Preferentially nocturnal, during rest, after eating or drinking

Preceded by bradycardia

Lower ventricular response rate during AF

Aggravation by beta blocker and/or digoxin

Digoxin, verapamil, sotalol, and flecainide are poor choices

Disopyramide and quinidine better

Propafenone not very effective because of beta blocking properties

Correct PV ablation is effective in curing paroxysmal AF. Different treatment for vagal and adrenergic.

Careful history-taking is important for accurate diagnosis and appropriate pharmacological and ablation treatment of AF.

Specific IKACh channel blockers may become the treatment of choice for vagal AF in the future. (KAC is supposed to be a subscript.)

[EngMac]

Oh, I forgot to mention the study said some people have mixed, or a bit of both. I would expect then it is much harder to treat.

[CDreamer]

My understanding, from other studies, is that you can also have a mix of both types.

[BobD Volunteer]

That is interesting Mac as somebody else posted this or a similar study a few days ago although I thought it was more recent than 2007. I think it is widely accepted now that vagal AF exists but it has been a bit of an uphill struggle getting some doctors to accept that. The general fall back solution of beta blockers at first presentation I have questioned many times here.

What is important to understand is that treatment of AF is only about 20 years old as up to the mid nineties you would have been told there is nothing we can do it is a benign nuisance so get on with life. In fact it was only about 2007 that the link to stroke and the drive for anticoagulation started and I remember been quite shocked when I learned of it. Prior to that NOBODY had ever mentioned to me that stroke was a risk with AF. I can tell you almost to the time and date as I was in a policy meeting at British Heart Foundation at the time.

Yes there has been a great deal of progress over the years since but I don't think we have really done much more than scratched the surface of this mongrel condition yet.

[ILowe]

I was asked to update a recent post on this subject so will add to this thread. Here is what I have found, with my commentary.

The original article referred to was: Autonomic trigger patterns and anti-arrhythmic treatment of paroxysmal atrial fibrillation: data from the Euro Heart Survey. Google this, it is free if you are a member of researchgate. They basically tried to distinguish between two types of AF: Adrenergic, which is triggered by emotional stress and exercise, usually daytime, associated with heart disease, best treated with betablockers. Vagal, usually under 50, male, AF happens at night, at rest, after a meal or alcohol, can be preceded by bradycardia, is less likely to progress to permanent, and use an antiarrhythmic.

BUT, the clear distinction was in less than a third of patients, and most people have a mixture, so for most people, the rate/rhythm control must be decided by other factors.

Husterman 2013, Role of stress in Cardiac Arrhythmias

jafib.com/published/webForm...

Excellent article, easy to read, helpful in many areas. See in particular the fourth page, page 77-8 where the more recent evidence is summarised. I note: “beta-blockers applied in patients with the vagal type of atrial tachycardia/AF may promote arrhythmogenesis and increase the frequency of arrhythmic events.”. So, betablockers, in vagal AF, may make things worse, just like over-use of Flecainide can make things worse.

** Guidelines for the management of atrial fibrillation 2010. eurheartj.oxfordjournals.or...

This is getting a bit old now. But here are a few quotes

“Patients with atrial fibrillation and minimal or no heart disease (lone atrial fibrillation). In patients with no or minimal heart disease, b-blockers represent a logical ?rst attempt to prevent recurrent AF when the arrhythmia is clearly related to mental or physical stress (adrenergic AF). Since b-blockers are not very effective in many other patients with ‘lone AF’, fecainide, propafenone, sotalol, or dronedarone is usually prescribed. Disopyramide, which has marked anticholinergic effects, may be useful in vagally mediated AF”

There is a fascinating review of drugs to maintain sinus rhythm. “Flecainide approximately doubles the likelihood of maintaining sinus rhythm. Flecainide was initially evaluated for paroxysmal AF, but is also used to maintain sinus rhythm after DCC. It can be safely administered in patients without signi?cant structural heart disease”

That is all I can find.

What we are down to, is a lot of opinion. A Cochrane review (tough evidence based) has found insufficient evidence.

[souljacs4]

That's interesting. Does anyone know what research if any is being done for new treatments into AF.

[ILowe]

We are also faced by a problem of classification. But, at least some good questions are being asked. One of my favorite quotations on this is 'Far better an approximate answer to the right question, which is often vague, than an exact answer to the wrong question, which can always be made precise.' (Tukey 1962:13-14).

For some people the distinction will be helpful. For most others, like myself, I probably fit into the mixed heading. I am not under any regular meds, but take either Flec or Bisoprolol, or both, as needed. What I have learned is, that if the increased heart rate is preceded by emotional stress, or excessive exercise, or unusual irregularities, then Flec is probably the answer. But if I get a classical tachycardia and vagal manoevres do not work, then bisoprolol is most likely to help.

[rosyG]

I have vagal AF and found studies showing that if treated with beta blockers and digoxin patients often had permanent AF by year end whereas none of those treated differently progressed to permanent in that time frame.

There were 3 good studies which I showed to the South East Coast AF clinical group and they accepted these and put a note in the guidance now used to say that beta blockers and digoxin are contra indicated with vagal AF

It is interesting when people have both types but I would think that beta blockers and digoxin would still be best avoided! ( I am not medically qualified- except an ancient nursing qualification SRN- changed track later on !!)

[JonathanPittsCrick]

I have found vagal-type AF quite common and treatment with a pacemaker to prevent bradycardia (and especially sinus pauses) at night is very effective long-term. For mixed-type AF a pacemaker + flecainide or low dose bisoprolol can be used.

Many patients comment on how much better they sleep after the pacemaker implantation. It seems like they were getting a kind of "sleep apnoea syndrome of the heart" i.e. when the heart goes too slowly the brain gets upset at sends a burst of adrenaline to speed it up. This then partially wakes the brain up as well so it never gets the deep (REM) sleep it needs.

Unfortunately the EP whiz-kids are so keen on AF ablation that simpler alternatives can get forgotten.

[EngMac in reply to JonathanPittsCrick]

This describes my symptoms exactly. My EP was not very helpful in finding a solution and did not suggest your solution. I sent you a private message that I hope that you will kindly answer.

[JonathanPittsCrick]

I have answered - but for this thread I would like to add that for most people with slow sinus rates and limited "chronotropic" (increasing rate) response to exercise, a pacemaker also gives them a lot more energy, improved circulation and even better mental concentration.