Disorder - Atrial septal defect

Organ Systems Involved
Cardiovascular

Alternative disorders described within LIDA

Mitral dysplasia; Tricuspid dysplasia; Aortic stenosis; Pulmonic stenosis; Ventricular septal defect; Congenital aortic insufficiency; Teratology of Fallot; Patent ductus arteriosus

Alternative Names
ASD; Sinus venosus; Ostium primum; Ostium secundum

Presenting Signs

Atrial septal defect (ASD) is caused when there is a hole in the septum or wall between the right and left atria (chambers of the heart). This causes communication, or blood mixing, between the two septa. This disorder is common in humans but has been considered until recently to be extremely rare in cats and dogs. However, this disorder is now being diagnosed more frequently in cats and dogs because of the recently increased use of echocardiographic and Doppler imaging techniques.

Three types of ASD have been described according to the site of the defect in the atrial septum: Ostium primum, Ostium secundum and Sinus venosus. Ostium secundum is the most common type of ASD diagnosed in cats.

In the vast majority of cases ASD is detected by accident when another condition is being investigated, as the defect usually shows no clinical signs. For the small percentage of animals that do show symptoms, these most commonly include a heart murmur, reluctance to exercise, fainting, coughing and difficulty breathing.

Treatment

Surgical/Medical/None. No treatment is necessary for the majority of defects.

PubMed References
Atrial septal defect

Contributor
Megan Jolly