Balloon Valvuloplasty of Tricuspid Stenosis: A Retrospective Study of 5 Labrador Retriever Dogs

Background: There are limited reports of severe tricuspid valve stenosis in dogs and limited data regarding treatment and outcome. Objective: To evaluate clinical signs, echocardiographic features, and outcome of balloon valvuloplasty (BV) in dogs with severe tricuspid valve stenosis (TVS) in which BV was attempted. Animals: Five client-owned dogs with severe TVS. Methods: Records were retrospectively reviewed and data collected regarding signalment, clinical signs, diagnostic findings, procedures, and outcome. Results: All dogs were Labrador Retrievers. Presenting complaints included episodic weakness/syncope (4/5), abdominal distension (4/5), lethargy (2/5), and exercise intolerance (2/5). The median and range of measurements before BV were as follows: TV mean velocity 1.5 m/s (range 1.4–1.7 m/s); velocity-time integral (VTI) 79.8 cm (42.4–99.1 cm); and TV maximum velocity 2.9 m/s (2.3–3.2 m/s). Measurements (available for 3 of 5 dogs) after BV were as follows: TV mean velocity 1.15 m/s (0.9–1.4 m/s); VTI 44.95 cm (41.4–54.8 cm); and TV maximum velocity 1.15 m/s (1.9–2.3 m/s). The procedure was attempted in all dogs and completed in 4/5 dogs. The largest balloon diameter ranged from 15 mm to 25 mm, and length ranged from 4 cm to 5 cm. Right atrial pressure decreased in 4/5 dogs. All but 1 dog had clinical improvement after BV, but recurrence of clinical signs occurred (2/5). Tricuspid regurgitation worsened in 1 dog culminating in right heart failure and euthanasia. Conclusions and Clinical Importance: BV can be an effective treatment; however, clinical signs can recur. Right heart failure due to worsened TR is a potential complication in dogs with pre-existing moderate-to-severe TR.