The hallmark EKG findings are the presence of an irregular rhythm and absence of P waves. Due to a very high number of microfoci in the atria that are all firing independently. They are competing to activate the A-V node. Due to disorders associated with atrial dilation. These individuals usually have slow to normal ventricular rates.
Cardiac output falls due to a loss of atrial contraction.
At slower rates, the atria contribute relatively little to ventricular filling. The rapid heart rates also result in an increase in myocardial oxygen consumption. This can result in more myocardial hypoxia which causes a reduction in inotropy and exacerbation of dysrhythmias. Convert the rhythm to a sinus rhythm. Although propranolol is the best known beta blocker in veterinary medicine, it has drawbacks in its combined beta 1 and beta 2 blocking activity.