The aorta is the great artery that leaves directly from the left ventricular chamber of the heart. It is the main trunk of the circulatory system and supplyies blood to virtually all bodily tissues. “Stenosis” is defined as the narrowing or contraction of a body opening or passageway, from whatever cause. Therefore, “aortic stenosis” is an obstruction to the outflow of blood from the left ventricle into the aorta due to some narrowing or constriction. It is a common condition in domestic dogs. In fact, it is reported to be the second most common congenital canine heart defect, second only to another condition called patent ductus arteriosis. Some authorities place aortic stenosis first in this category.
Aortic stenosis can be caused by a number of things. It can result from some defect or malformation of a heart valve (valvular aortic stenosis), by an obstruction in that part of the aorta known as the ascending aorta (supravalvular aortic stenosis), or by an obstruction in the outflow path of blood leaving the left ventricle through the descending aorta (subvalvular aortic stenosis). Supravalvular aortic stenosis is the most common form of this condition in
Subaortic stenosis (SAS) typically develops after a puppy is born, during the first weeks to months of its life. However, clinical signs of the disorder often do not appear until later. The onset of noticeable signs of SAS can happen at any age and depends largely upon the severity of the blockage or obstruction of blood outflow from the left ventricle into the aorta. In most cases, the disorder can be identified by the time
Any dog suspected of having heart problems or other systemic disease will be given a thorough physical examination by the attending veterinarian, who will also take a history from the dog’s owner. Dogs with subaortic stenosis (SAS) usually have normal results on a urinalysis and on routine blood work, including a complete blood count (CBC) and a serum biochemistry profile. The next step in gathering the initial data base usually is thoracic radiographs (chest X-rays),
The goals and types of treatment for dogs diagnosed with subaortic stenosis (SAS) are somewhat controversial, even among veterinarians. There is no universally agreed-upon treatment protocol. Certainly in severe cases, the therapeutic goal is to try and reduce the risk of fainting episodes (syncope) and sudden death. If the dog has developed congestive heart failure as a result of SAS, treatment for that condition should be implemented; this typically involves administration of a combination of