C14 - Coronary Ostial Eccentricity, Aortic Rotation, and Cusp Symmetry in Dogs Evaluated by Cardiac Computed Tomography

Abstract:

Background: Coronary ostia may vary in location within the aortic cusps. Brachycephalic dogs have an increased risk for anomalous coronary artery anatomy (aCAA). The aim of this study was to evaluate aortic root rotation and asymmetry of aortic cusp size and their association with aCAA in dogs.

Hypothesis/

Objectives: Coronary ostia are not centrally located within the aortic cusps and this eccentricity is greater in brachycephalic dogs. Aortic root rotation and aortic cusp asymmetry are associated with aCAA.

Animals: 105 dogs with cardiac computed tomography including 22 normal, 19 PS with aCAA, and 64 PS with normal CAA.

Methods: Retrospective, observational study. Each coronary ostial opening was determined as an angle relative to aortic cusp midpoint. Symmetry of the aortic cusps was determined by planimetered area. Rotation of the aortic root was calculated as deviation of the midpoint of the non-coronary cusp from the plane of the interatrial septum.

Results: The left coronary ostium of dogs had a median eccentricity of 19.5 degrees (95%CI: 14.3 to 22.5) toward the left-right commissure; no difference was observed between brachycephalic and non-brachycephalic dogs (P=0.3). The area of the cusps were not different in dogs with aCAA as compared to dogs with normal CAA (P>0.3). Aortic root rotation was greater in brachycephalic dogs (16.7 +/- 20.3 degrees) than in non-brachycephalic dogs (6.1 +/- 15.7; P=0.01).

Conclusions and Clinical Importance: Brachycephalic dogs have aortic root rotation. Presence of aCAA is not related to asymmetry of the aortic cusps. The pathoetiology of aCAA remains uncertain.