Clinical and echocardiographic findings of pulmonary artery stenosis in seven cats.

OBJECTIVES

Describe the clinical, electrocardiographic (ECG), radiographic and echocardiographic findings in cats with isolated pulmonary artery stenosis. Assess the usefulness of systolic and diastolic Doppler measurements at predicting stenosis severity.

BACKGROUND

Pulmonary artery stenosis is an infrequent congenital cardiac defect in humans that has not been reported in cats. In humans, pulmonary artery stenosis is usually seen in conjunction with other cardiac defects and may lead to clinical signs if severe.

ANIMALS, MATERIALS AND

METHODS

Seven cats with pulmonary artery stenosis were retrospectively evaluated. Medical records, radiographs, ECGs, echocardiograms and angiocardiograms were reviewed. Severity of stenosis was assessed by two-dimensional and color Doppler echocardiographic evaluation and clinical findings. Peak systolic and diastolic gradients across the stenosis, and systolic and diastolic pressure decay half-times were graded using echocardiography. In addition, the duration of antegrade flow during diastole was subjectively assessed. Univariate analyses were performed to assess the best variable to predict stenosis severity.

RESULTS

Concurrent congenital defects were not identified. Only cats with severe obstruction showed clinical signs including exertional dyspnea and lethargy. Diastolic Doppler measurements were superior to systolic measurements at predicting severity of stenosis. Antegrade flow throughout diastole and/or a diastolic pressure half-time of >100 ms indicated severe obstruction. The prognosis for pulmonary artery stenosis appears to be good regardless of severity.

CONCLUSION

Among cats with pulmonary artery stenosis, clinical signs are uncommon and prognosis is good. Doppler assessment of diastolic flow appears to be superior to systolic flow at predicting severity.