Agitated saline contrast use in a case with peripheral pulmonary artery stenosis

We present a case of peripheral pulmonary artery stenosis that was incidentally detected by agitated saline contrast study. A 19-year-old male patient underwent cardiologic examination to determine suitability for military service. He had exertional intolerance since early childhood. Physical examination showed a murmur over the entire right hemithorax. Echocardiography showed moderately enlarged right ventricle, right atrium, and main pulmonary artery, and color Doppler showed mild tricuspid regurgitation. Right ventricular systolic pressure was estimated as 55-60 mmHg from the tricuspid regurgitation jet. For further evaluation of the systolic murmur, agitated saline contrast echocardiography was performed. During continuous wave Doppler examination while there were remnants of bubbles in the right heart and pulmonary vascular bed, a systolodiastolic flow with a peak gradient of 30 mmHg was noted. After disappearance of the bubbles, the signal was not detectable. Repeat agitated saline contrast examination again showed a gradient of 35 mmHg. A stenosis in the distal branches of the right pulmonary artery was suspected. Finally, computed tomography revealed multiple stenoses in the pulmonary vascular bed. To our best knowledge, this is the first case in which agitated saline contrast examination enabled the diagnosis of peripheral pulmonary artery stenosis.