Changes

===Small Animals===

===Small Animals===

Patients with primary atrial fibrillation are usually asymptomatic. However, there may be signs of haemodynamic compromise due to the rapid heart rate and a loss of atrial contribution to ventricular filling; which would usually account for up to 20% of cardiac output.  

Patients with primary atrial fibrillation are usually asymptomatic. However, there may be signs of haemodynamic compromise due to the rapid heart rate and a loss of atrial contribution to ventricular filling; which would usually account for up to 20% of cardiac output. This most commonly manifests as exercise intolerance.  

Other signs are generally related to the underlying disease process or [[:Category:Heart Failure|'''congestive heart failure''']]. There may be a history of coughing, dyspnoea, tachypnoea, exercise intolerance, episodes of syncope.

Other signs are generally related to the underlying disease process or [[:Category:Heart Failure|'''congestive heart failure''']]. There may be a history of coughing, dyspnoea, tachypnoea, exercise intolerance, episodes of syncope.