Clinical characteristics of 53 dogs with Doppler-derived evidence of pulmonary hypertension: 1992-1996

Pulmonary hypertension occurs as a primary or secondary disorder of the pul monary vasculature. Doppler echocardiography provides a noninvasive tool fo r the estimation of pulmonary arterial pressure when tricuspid regurgitatio n or pulmonic insufficiency is present. The cardiology database at Colorado State University was reviewed, and echocardiographic records from cases di agnosed with pulmonary hypertension were evaluated. Application of the modi fied Bernoulli equation to the maximal instantaneous velocity of a right-si ded regurgitant jet provided evidence of pulmonary hypertension in 53 dogs over a 4-year period. Tricuspid regurgitant velocity greater than or equal to 2.8 m/second or pulmonic insufficiency velocity greater than or equal to 2.2 m/second was considered abnormal and indicative of pulmonary hypertens ion. Tricuspid regurgitant gradients in 51 dogs ranged from 32 to 145 mm Hg (mean, 63.0 mm Hg; median, 57.0 mm Hg; 25th-75th percentiles, 45.2-76.5 mm Hg). Pulmonic insufficiency gradients in 8 dogs ranged from 20 to 100 min Hg (mean, 59.5 mm Hg; median, 61.5 mm Hg; 25th-75th percentiles, 32.0-84.5 mm Hg). Affected dogs ranged in age from 2 months to 16 years. Clinical sig ns were characteristic of cardiopulmonary disease, but a relatively high fr equency of syncope was noted (12 of 53 dogs, 23%). Pulmonary hypertension w as probably due to increased pulmonary vascular resistance ill 23 dogs, pul monary overcirculation in 2 dogs, and pulmonary venous hypertension in 23 d ogs. Five dogs lacked a clinically recognizable cardiopulmonary cause of pu lmonary vascular disease. Our results suggest that pulmonary hypertension c an occur as a complication of commonly encountered cardiopulmonary diseases , and that Doppler echocardiography can facilitate recognition of this cond ition.