Correlation of transthoracic echocardiographic and angiographic measurements of pulmonary valve annular diameter in dogs with pulmonary stenosis.

INTRODUCTION/OBJECTIVES: Dogs with severe pulmonary stenosis (PS) are routinely treated with balloon valvuloplasty. Success and safety of these procedures require an accurate assessment of the pulmonary valve annulus (PVA) diameter for proper balloon catheter selection. PVA diameter is assessed with angiography (PVA-Ang) and transthoracic echocardiography (PVA-TTE), and both may impact procedural planning for balloon valvuloplasty. The objective of this study was to describe the relationship between PVA-Ang and PVA-TTE in dogs with PS.

ANIMALS, MATERIALS AND METHODS: Observational, retrospective study of 59 client-owned dogs. Medical records of dogs diagnosed with PS were reviewed. Images from selective right ventricular angiography and transthoracic echocardiography were reviewed. The PVA diameters were measured at the time of angiography (PVA-Ang) and by a single operator for this study (PVA-TTE). Image quality scores were assigned to echocardiographic images of the PVA based on visualization of PVA margins and valve leaflet hinge points.

RESULTS

In 41/59 (70%) dogs, the diameter of the PVA-Ang was larger than the PVA-TTE, and the (range 0.1 to 8.4 mm) worse echocardiographic image quality, the difference in measurement between modalities increased. Dogs with poor echocardiographic image quality had greater differences (range -7.7 to 8.4 mm) between PVA-Ang and PVA-TTE compared to those with excellent image quality (range -2.2 to 3.8 mm), and the absolute differences between poor (median 2.8 mm, range 1.5-8.4 mm) and excellent (median 1.4 mm, 0.2-3.8 mm) image quality were significant (P=0.005).

CONCLUSIONS

Diameters of PVA-Ang are greater than PVA-TTE in most dogs, and these differences are most apparent with worse echocardiographic image quality. These differences may be clinically relevant to interventional procedure planning.