Name: Red
Age: 10 months
Sex: Male, intact
Breed: Irish Setter

Please review Red’s clinical history.

Red was presented for a neuter.  He is reported to be healthy and well at home.  A left basilar systolic heart murmur was noted on physical examination and a pre-anesthetic ECG was therefore obtained.    

View Red’s electrocardiogram (the black bar represents one second)

 

Discussion:  In this young dog with a heart murmur, the presence of a right axis deviation should prompt the veterinarian to consider congenital heart defects that could cause right ventricular enlargement or hypertrophy – such as tricuspid valve dypslasia, atrial septal defect, or pulmonary valve stenosis. This recording is from a dog with pulmonary valve stenosis who had severe right ventricular hypertrophy noted on the echocardiogram. Treatment/management: There is no treatment for the rhythm as the underlying rhythm is sinus and sinus arrhythmia is a common finding in normal dogs. The axis deviation implies there is something abnormal in the heart’s conduction system and suggests a right-sided heart lesion. Given the concurrent heart murmur, referral for an echocardiogram and definitive diagnosis prior to anesthetizing this dog is advised.