Diagnostic Value of Echo-Doppler and Tissue Doppler Imaging in Dogs with Pulmonary Arterial Hypertension

Abstract

Background: Diagnosis of pulmonary arterial hypertension (PAH) relies on Doppler measurement of pulmonic and tricuspid regurgitation (TR). However, these are not always detectable.Hypothesis: Tissue Doppler imaging (TDI), a novel noninvasive ultrasound technique, provides indirect but sensitive and specific assessment of elevated systolic pulmonary artery pressure (SPAP) in dogs.Animals: One hundred and five dogs with TR. Methods: Prospective observational study. Dogs were categorized as presenting normal (group 1, n 5 45), mildly increased (group 2, n 5 19), or moderately to severely increased (group 3, n 5 41) SPAP, based on TR peak velocities (,2.5, 2.5-3.0, and .3.0 m/s, respectively). Ten quantitative echo-Doppler-and TDI-derived variables were assessed, including the main pulmonary arterial diameter to aortic diameter ratio, pulmonary flow acceleration time, and acceleration-to-ejection time ratio, the Tei index of right ventricular function, and 6 longitudinal basal right ventricular TDI variables.Results: A significant correlation was observed between SPAP and each of the 10 tested variables (P , .05). Conventional echo-Doppler variables were less discriminating than the TDI for predicting increased SPAP. The combined systolic and diastolic right TDI index had the highest sensitivity and specificity (89% and 93% respectively, for a cutoff of 11.8 cm/s) and could discriminate between dogs in group 1 from dogs in group 2.Conclusions and Clinical Importance: TDI provided effective predictors of systolic PAH and demonstrated that both alterations in right-sided systolic and diastolic myocardial function can occur with mild increases in SPAP.

Diagnostic Value of Right Pulmonary Artery Distensibility Index in Dogs with Pulmonary Hypertension: Comparison with Doppler Echocardiographic Estimates of Pulmonary Arterial Pressure

“…From the same view used to quantify the RPAD index, diastolic measurements of the internal dimensions of the main pulmonary artery (MPA) in long axis and the ascending aorta (Ao) in short axis were obtained, and the MPA:Ao ratio was calculated 10. The MPA measurement was obtained approximately midway between the pulmonary valve and origin of the right and left PAs 22…”

Comparison of a computed tomographic pulmonary trunk to aorta diameter ratio with echocardiographic indices of pulmonary hypertension in dogs

“…A diagnosis of pulmonary hypertension was made based on a peak tricuspid regurgitation pressure gradient of greater than 30 mm Hg; a peak pulmonary insufficiency pressure of greater than 16 mm Hg; a ratio of main pulmonary artery diameter to aortic root diameter ratio >0.98; and/or an right ventricular acceleration time‐to‐ejection time ratio of less than 0.31 . Four categories of peak tricuspid regurgitation pressure gradient were utilized based on previously described thresholds of severity: no pulmonary hypertension, tricuspid regurgitation ≤30 mm Hg; mild pulmonary hypertension, tricuspid regurgitation 31–≤50 mm Hg; moderate pulmonary hypertension, tricuspid regurgitation 51–≤75 mm Hg; and severe pulmonary hypertension, tricuspid regurgitation > 75 mm Hg, respectively …”

“…Right heart catheterization is the definitive technique to measure pulmonary artery pressure. However, cardiac catheterization is an invasive procedure that requires general anesthesia and is not routinely performed in dogs in a clinical setting . Two‐dimensional and Doppler echocardiography currently provides the most accurate, noninvasive, available, and cost‐effective estimation of pulmonary artery pressure in dogs.…”

“…When tricuspid regurgitation is present an indirect estimation of pulmonary systolic arterial pressure can be obtained using the modified Bernoulli equation . Other parameters used to estimate the presence of pulmonary hypertension include evidence of right ventricular dilation and/or concentric hypertrophy, interventricular septal flattening, right atrial enlargement, the ratio of main pulmonary artery diameter to aortic root diameter, pulmonic valve diastolic pressure gradient (when insufficiency is present), pulmonary artery time to peak velocity or acceleration time, acceleration time to right ventricular ejection time ratio (AT:ET), right ventricular tissue Doppler imaging, tricuspid annular plane systolic excursion, and right pulmonary artery distensibility . Thoracic radiology is not considered a reliable test for pulmonary hypertension .…”

Holter Monitoring of Small Breed Dogs with Advanced Myxomatous Mitral Valve Disease with and without a History of Syncope

“…Dogs with PAH often present with a history of syncope and PAH has also been associated with MMVD 49, 50, 51, 52. In this study, blood pressure and PAH assessed via peak TR velocity did not differ much between dogs with and without a history of syncope (Table 1).…”