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.