Doppler Echocardiography in the Diagnosis and the Estimation of the Severity of the Infundibular Pulmonic Stenosis

ABSTRACT

BACKGROUND: The diagnosis and estimation of severity of infundibular pulmonic stenosis (PS) is difficult by two-dimensional or M-mode echocardiography. In continuous wave(CW) Doppler signal valvular PS is seen as a parabolic velocity profile but infundibular PS is seen as a velocity signal with its peak in late systole. The purpose of this study is that Doppler echocardiography can discriminate valvular PS from infundibular PS and assess the severity of infundibular obstruction. METHOD: Six patients with valvular and infundibular PS by Doppler echocardiography and cardiac catheterization were studied. All had been undergone surgery. We compared their Doppler echocardiographic and cardiac catheterization finding with surgical finding. RESULT: 1) CW Doppler signal of infundibular PS had lesser peak velocity(2.84m/sec vs 4.33m/sec, p < 0.05) and later systolic peak in velocity(AT/ET ratio 0.73 vs 0.51, p < 0.05) than that of valvular PS. 2) Pressure gradient across the infundibular obstruction measured by Doppler echocardiography correlated well with that by cardiac catheterization(r=0.89, p < 0.05). 3) Operation finding showed infundibular PS in 5 case but not one and coexisting other anomaly such as ASD in 4 case, TOF in 1 case, PAPVR in 1 case. CONCLUSION: Doppler echocardiography is a useful noninvasive method for the diagnosis and the estimation of severity of infundibular obstruction in patient with PS.