Ventricular Septal Defect: Our Case of the Month June 2024

This case was imaged by Shari Reffi, CVT, SDEP® Certified Clinical Sonographer at New Jersey Mobile with detailed interpretation by Eric Lindquist, DMV, DABVP, Cert. IVUSS.


A 6-month-old intact male Sphynx cat was referred for an echocardiogram as a pre-anesthetic evaluation for his neuter.

Grade II/VI heart murmur.

No clinical signs, no current medications.



A ventricular septal defect was noted in this patient with left to right shunting of 5.0 m/s. Minor tricuspid insufficiency was noted. Eccentric right ventricular hypertrophy was noted, owing to volume overload with mild right atrial enlargement. The ventricular septal defect measured approximately 4.0 mm. The left ventricular septum and free wall were structurally normal with normal internal diameter.


Ventricular septal defect with left to right shunting of 5m/s. Minor tricuspid insufficiency. Eccentric hypertrophy of the right ventricle secondary to volume overload.


There is mild anesthetic risk in this patient currently; prognosis long term is guarded. This is a congenital defect and the cat is unfit for sale if this is a breeding stock. A recheck is recommended echo in 3-6 months to assess any progression. 


Ventricular septal defect (VSD) accounts for 56% of all congenital cardiac defects in cats.. A VSD can occur anywhere along the septum of the ventricles; however, they are most commonly found in the basal septum with the left side of the defect located just below the aortic valve. The right parasternal 4 chamber is best for viewing defects at this position. Clinical signs will be determined by the shunt size and the velocity of flow across the defect. Small VSDs that are less than 40% aortic diameter, with a velocity greater that 4.5m/s, have an excellent prognosis and the patient typically lives a normal life span with no treatment. Depending on shunt volume, the patient may develop volume overload of the left heart and pulmonary artery. Patients with large VSDs have a more guarded prognosis in that pressure may equilibrate across both chambers with subsequent left sided congestive heart failure (CHF) developing. In some cases, pulmonary hypertension may develop causing reversal of the shunt. Management for CHF may be necessary. Alternatively, surgical options include pulmonary artery banding, or closure of the defect.

Velocity across the VSD.

Right ventricular hypertrophy and left atrial enlargement.

Measurement across VSD.

Color showing turbulent flow through VSD.

B mode 4 chamber showing VSD.

No update was available on this case at the time of publication.

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Course topics include :

1.Cardiology is simple and logical

2. Doppler – How to Adjust and How to Interpret

3. Degenerative Mitral Valve Disease – Getting the Right Data for the Right Decisions

4.DCM (dilated cardiomyopathy) – What Ultrasound Can Tell Us

5.Pulmonary Hypertension – How Not to Miss It

6.Help! I Can’t Get That View!

7.Cats: A Different World – Feline Heart Disease

8.Cliff Notes on ECG