Long term effect of afib on atrial diameter

I am a 65 year old male (6' 5"  270 lbs) with a 30 year history of atrial fibrillation.  Rythmol worked well for many years but has now seemed to lose its effectiveness. After an unsuccessful try to increase dosage, I am now in continuous afib.

Because I am relatively asymptomatic, have a low resting afib heart rate (55-75 bpm) and my left atrium is enlarged (5.5 cm), a consulting EP told me that I was a poor candidate for an ablation. He suggested that I either give rhythm control one more chance or live with permanent afib and rate control.  

I will be seeing my cardiologist Nov. 19th. He is willing to switch me to sotolol and try another cardioversion. He will not consider using tykosin, flecainide, or similar antiarrhythmic drugs because I have some CAD. Frankly, he would prefer that I opt for rate control.  However, I am concerned about the long term effects of afib on my heart, in particular causing my left atrium to dilate even further.

Have there been any studies on the long term affects of afib rate control on atrial diameter? My left atrium is already dilated at 5.5 cm diameter.

Will my atria continue to dilate with time or will it reach a steady state size? What will be the long term complications if the atria continue to enlarge?

BTW, my ventricles appear normal and the EP I consulted with thought it unlikely that the ventricles would be damaged by the afib because of my relatively low afib heart rate.  Do you agree?

[Michael J. McWilliams, M.D.]

He is willing to switch me to sotolol and try another cardioversion. He will not consider using tykosin, flecainide, or similar antiarrhythmic drugs because I have some CAD.

If you are  candidate for sotalol, you should also be a candidate for tikosyn -- that is unless you are on a medication that you must have that doesn't mix with tikosyn (there are  few).

Have there been any studies on the long term affects of afib rate control on atrial diameter?

If you are on chronic atrial fib, you will likely experience further dilation in your atria.  There isn 't a defined size when they stop dilating but in general, the atria don't get too large unless their is valvular disease (you would know if you had this already).

What will be the long term complications if the atria continue to enlarge?

There is an increased risk of stroke and the risk of stroke is cumulative. If your risk is 4% per year, it is a 40% risk over 10 years.  The important thing to know is that the rhythm control strategy is only proven to help symptoms.  It does not decrease hospitalizations, heart failure, death, or stroke.  The only reason for rhythm control is to improve symptoms.  If you are relatively asymptomatic, I would agree that rate control is a good option and I would recommend aspirin or coumadin, depending on your risk profile.


BTW, my ventricles appear normal and the EP I consulted with thought it unlikely that the ventricles would be damaged by the afib because of my relatively low afib heart rate.  Do you agree?

The biggest cause of heart failure with atrial fibrillation is inadequate rate control.  If your rate is controlled, I would agree with your cardiologist that your risk of developing heart failure is low.

I understand that you have concerns that your atria will enlarge and they probably will.  What you also need to consider is that sotalol, tikosyn, flecainide, etc, all have their own risks.  The safest approach for someone with minimal symptoms and atrial fibrillation is rate control and I would tell my mom the say thing (that is my way of saying that I am being very honest about this).

I hope this helps.  Thanks for posting.

[va_tony]

Thank you very much Doctor.  That was exactly the info I was seeking. I really appreciate the effort you made to respond to my concerns.