Background: Description of the normal subleaflet anatomy of the mitral valve (MV) in dogs using three-dimensional (3D) transesophageal echocardiography (TEE) has not been well described. With advancements in MV interventions, understanding leaflet morphology becomes increasingly important. Hypothesis/
Objectives: To describe the subleaflet anatomy of the MV in apparently healthy beagle dogs. Variation in the subleaflet anatomy was hypothesized, with posterior leaflet anatomy expected to vary more than the anterior. Animals: Twenty healthy beagle dogs.
Methods: Prospective, descriptive study. Comprehensive TEE studies were performed and 3D images acquired. Studies were evaluated and MV anatomy was classified as classic or atypical. Classic MV anatomy was defined as a non-scalloped anterior leaflet and a posterior leaflet with only three scallops. Atypical anatomy referred to patients with accessory scallops and/or dichotomous posterior leaflet scallops.
Results: Classic MV anatomy was observed in 45% (9/20) of dogs. Accessory scallops were present in 45% (9/20) of dogs. The anterior leaflet comprised an average of 24.9% (±3.3%) of the mitral annular circumference. Variation in scallop size was observed, with the percentage of annular circumference occupied by each scallop ranging from P1: 19.2%–29.7%, P2: 19.4%–32.1%, P3: 16.6%–27.7%. Which scallop was largest varied among dogs, with P1 being the largest in 11/20 (55%), P2 in 6/20 dogs (30%), and P3 in 3/20 dogs (15%).
Conclusions: Variations in subleaflet morphology are present in apparently healthy dogs, with most variations noted in the posterior leaflet. Accessory and dichotomous posterior scallops are common in healthy Beagle dogs.
