Atrioventricular septal defects: natural history, echocardiographic, electrocardiographic, and radiographic findings in 26 cats

Abstract

Objectives: To evaluate signalment, echocardiographic, electrocardiographic, and radiographic findings as well as natural history in a group of cats with atrioventricular septal defects (AVSD).

Animals: 26 client owned cats.

Methods: Medical records were reviewed retrospectively for signalment, morphologic type of AVSD, presence of concurrent congenital heart disease (ConcCHD), diagnostic findings, and natural history.

Results: Seventeen cats had an isolated AVSD; 13/17 had a partial and 4/17 had a complete AVSD. Double outlet right atrium (DORA) was diagnosed in 4/17 cats. Of those with a partial AVSD, 7/13 had an atrial communication while 6/13 had a ventricular communication. Congestive heart failure (CHF) developed in 5/17 cats; all 3 cats diagnosed with a DORA not lost to follow-up developed pulmonary edema. Sudden death was documented in 4/17 (23.5%). The 5 year survival was 53.0% (9/17). Concurrent congenital heart disease was identified in 9/26 cats with 7/9 having a conotruncal abnormality. Electrocardiography was performed in 14 cats with 11/14 diagnosed with a conduction disturbance.

Conclusions: Overall the echocardiographic and electrocardiographic findings with AVSD are similar to that seen in humans. Cats may have a higher prevalence than humans of partial AVSD with ventricular communication only as well as a higher prevalence of DORA. Cats with an AVSD have an overall guarded prognosis although some can live for a protracted time.

Keywords: Atrioventricular canal defect; Double outlet right atrium; Endocardial cushion defect; Feline; Primum atrial septal defect.