Disorder - Subvalvular pulmonary stenosis

Organ Systems Involved
Cardiovascular

Alternative disorders described within LIDA

Atrial septal defect; Aorticopulmonary septal defect; Ventricular septal defect; Tetralogy of Fallot; Hypertrophic cardiomyopathy

Alternative Names
Infundibular pulmonary stenosis

Presenting Signs

Subvalvular pulmonary stenosis is an abnormal narrowing in the region of the heart where blood is pumped into the blood vessel leading to the lungs. The increased turbulence of blood flowing through the narrowed area results in a loud heart murmur that can be heard with a stethoscope, and vibrations can sometimes be felt through the chest wall. The heart may have an irregular rhythm and the pulse strength may be reduced.

Affected animals present with signs related to the heart and lungs such as lethargy, exercise intolerance, open mouth breathing, coughing, a swollen neck vein (the jugular vein), a very loud heart murmur, congestive heart failure, purple gums (due to lack of oxygen in the tissues), collapse or seizures. Sudden death can occur in extreme cases.

Cats at Risk

Based on the case reports, it appears that male cats are more commonly affected than female cats.

Breeds Affected
Abyssinian
Devon Rex


Treatment

Surgical: a balloon catheter is inserted through a neck vein and advanced towards the heart. The balloon catheter is repeatedly inflated in an attempt to dilate the narrowed area within the heart. This technique is known as balloon valvuloplasty and has been shown to reduce clinical signs in severely affected animals.

PubMed References
Subvalvular pulmonary stenosis

Contributor
Bee Sze Koh