Congenital Heart Defect (Ebstein’s Anomaly) in Cats

Ebstein's Anomaly in Cats

Ebstein's anomaly is a rare congenital malformation of the heart in which the opening of the tricuspid valve (on the right side of the heart, between the right atrium and the right ventricle) is displaced toward the apex of the right ventricle of the heart. It is accompanied by various degrees of tricuspid insufficiency, such as stenosis – an abnormal narrowing in a blood vessel, or rapid heart rhythms caused by an abnormal accessory pathway. A murmur can be detected with a stethoscope in young animals, though it can be much more difficult to hear irregular heart movements if there is stenosis. There is no breed or gender predilection toward this abnormality in cats.

Symptoms and Types

  • Cats with mild tricuspid insufficiency or stenosis will typically be asymptomatic.
  • Moderate insufficiency, or stenosis, will often show as an intolerance for exercise
  • Severe insufficiency, or stenosis, will lead to congestive heart failure (CHF), with fluid in the chest or abdomen (swelling in the abdomen or chest may also be observed)
  • There may be some fatigue or dizziness associated with this condition, due to increased pressure on the heart to function


Your veterinarian will perform a thorough physical exam on your cat, including a chemical blood profile, a complete blood count, and a urinalysis. You will need to give a thorough history of your cat's health, including a background history of symptoms.

Your veterinarian will order an x-ray of the chest, and will look for evidence of right atrial and ventricular enlargement, as well as an enlarged kidney. Echocardiography can also be used to examine the heart and chest, by showing an ultrasound image of the size, motion and composition of the heart and surrounding structure. An electrocardiogram to measure the electrical activity and pressure within the heart will be necessary for verifying a definitive diagnosis of Ebstein's anomaly.

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