I would estimate 25-35% of the patients I see will experience at least one episode of a-fib with RVR while under my care. It can be an absolute nightmare to treat after cardiac or thoracic surgery.
There is a lot of intuition involved when choosing treatment. And while some of the professional societies have put out position papers on anti arrhythmic choice, the evidence grades are pretty poor. Thus, clinicians rely a lot on their own past experiences to determine their practice styles.
In general, folks with normal ejection fraction and normotensive with an initial episode get beta blockers first line. Those refractory to beta blockade may get Dilt or amio depending on my gut feeling. For lack of a better term, a patient with "soft" a-fib, meaning one which is likely temporary, usually due to myocardial irritation or inflammation, I like Dilt.
For those with "tough" a fib, folks with concomitant critical illness, history of recurrent a-fib, low ejection fraction, I tend to lean toward amio.
Again, these are generalizations.
I have seen hypotension with amio, though honestly I have experienced far more hypotension with dilt (especially when bolusing).
I try my best to avoid amio in pneumonectomy patients or those with severe COPD. I also tend to avoid it in patients with thyroid disease, though I have no evidence to account for either of these practices.
No matter which treatments I chose, I have found it best to "optimize" the physiologic conditions prior to any attempt at conversion or rate control. Typically this involves driving up the magnesium and calcium levels, high oxygen concentration prior to attempted conversion, increasing the coronary perfusion pressure and correcting any acid base abnormalities.
Overall, I think amio has great utility, even though it is not usually my first-line choice in hemodynamically stable patients.
