Changes

The aim is to control heart rate to a level that is less likely to result in haemodynamic compromise (rarely conversion to normal sinus rhythm).  

The aim is to control heart rate to a level that is less likely to result in haemodynamic compromise (rarely conversion to normal sinus rhythm).  

In '''dogs''' with AF secondary to '''structural heart disease''':

In '''dogs''' with AF secondary to '''structural heart disease''', '''Digoxin''' is usually the first line of therapy. Digoxin slows conduction through the AV node.  The goal is to keep the heart rate <150 bpm. Dogs should be re-assessed 5-7 days after starting Digoxin and serum Digoxin levels should be measured >8 hours post-administration.  If the heart rate remains high and the serum Digoxin level is within target range, a calcium channel blocker such as '''Diltiazem''' can be added. If compliance is good and finances are not limited, there may be additional benefit of an ACE inhibitor, Spironolactone and Omega-3 fatty acids. These help reverse structural remodelling and modulate pro-inflammatory cytokines that perpetuate arrhythmias.  

'''Digoxin''' is usually the first line of therapy. Digoxin slows conduction through the AV node.  The goal is to keep the heart rate <150 bpm. Dogs should be re-assessed 5-7 days after starting Digoxin and serum Digoxin levels should be measured >8 hours post-administration.  If the heart rate remains high and the serum Digoxin level is within target range, a calcium channel blocker such as '''Diltiazem''' can be added. If compliance is good and finances are not limited, there may be additional benefit of an ACE inhibitor, Spironolactone and Omega-3 fatty acids. These help reverse structural remodelling and modulate pro-inflammatory cytokines that perpetuate arrhythmias.  

In '''dogs''' with '''primary 'lone' AF''':

In '''dogs''' with '''primary 'lone' AF''' '''Amioderone''' should be administered if electric cardioversion is an option.  Amioderone increases the chances of remaining in sinus rhythm following cardioversion and some dogs may spontaneously convert to sinus rhythm with Amioderone alone. If electrical cardioversion is not an option, and the rate is >150bpm, then rate control is appropriate, using '''beta-blockers''' or '''Diltiazem'''. It is important to monitor these dogs for the development of structural cardiac disease, as AF may be seen in the occult phase of [[Dilated Cardiomyopathy|Dilated Cardiomyopathy]].

If '''electrical cardioversion''' is an option, start '''Amioderone'''. This increases the chances of remaining in sinus rhythm following cardioversion and some dogs may spontaneously convert to sinus rhythm with Amioderone alone. If electrical cardioversion is not an option and the rate is >150bpm then rate control is appropriate, using '''beta-blockers''' or '''Diltiazem'''. It is important to monitor these dogs for the development of structural cardiac disease, as AF may be seen in the occult phase of [[Dilated Cardiomyopathy|Dilated Cardiomyopathy]].

In '''cats''', atrial fibrillation usually indicates advanced structural heart disease with atrial dilation and is associated with a poor prognosis. The first-line drug of choice is  '''Diltiazem'''.  

In '''cats''', atrial fibrillation usually indicates advanced structural heart disease with atrial dilation and is associated with a poor prognosis. The first-line drug of choice is  '''Diltiazem'''.