- Second most common congenital heart defect after aortic valve dysplasia; 21% of feline congenital heart anomalies.
- Isolated subaortic lesion communicating ventral to septal tricuspid valve leaflet frequently identified, larger defect typical of tetralogy of Fallot.
- Occasionally combined with atrial septal defect producing common atrioventricular canal.
- Cause : congenital abnormality, resulting from anomalous formation of cardiac septa.
- Signs : vary from asymptomatic murmur to severe congestive heart failure.
- Diagnosis : auscultation, radiography, electrocardiography, ultrasonography.
- Treatment : medical management, surgery considered for severe cases.
- Prognosis : good with restrictive asymptomatic cases; poor with severe defects.
Print off the owner factsheet - (Congenital heart disease ventricular septal defect VSD) to give to your client.
- Diagonal murmur - harsh, holosystolic murmur with point of maximum intensity on the right, but murmur may also be heard over mitral valve.
- A murmur of relative pulmonic stenosis may be heard at left base of heart.
- Left-sided congestive heart failure (CHF).
- Eisenmenger's syndrome - marked dyspnea; cyanosis of mucous membranes; murmur may be reduced or absent.
Differential diagnosisSystolic murmurs in young cats
- Good - if mild, restrictive; normal life.
- Poor - if severe, cats with unrestrictive defects usually develop CHF within first few weeks of life.
- Hopeless - if Eisenmenger's syndrome.
Expected response to treatment
- Control of congestive heart failure (if present).
- Control of any dysrhythmias (if present).
Reasons for treatment failure
- Lesion too severe.
- Poor response to medical treatment.