DIAGNOSIS OF VENTRICUKAR SEPTAL DEFECT （VSD） BY ULTRASONIC PULSED DOPPLER REAL TIME SPECTRAL ANALYSIS

Thirty patients with clinically auspected congenital ventricular septal defect （VSD） were studied by ultrasonic pulsed Doppler real time spectral analysis technique. Of these patients, 19 are male and 11 female, their mean age being 10 years （range 3—30 years）.The spectral feature of VSD is demonstrated by recording abnormal systolic turbulence spectrum on the right sice of the ventricular septum, while disease other than VSD are diagnosed according to their specific features. For example, Patent Ductus Arteriosus （PDA） is charecterized by recording abnormal diastolic flow into the main pulmonary artery. All patients showed abnormal systolic flow feature. Surgery confirmed that 18 patients had pure VSD, 6 had VSD with subpulmonary stenosis or infundibular pulmonic stenosis, 2 had VSD with PDA, and 2 had hypertrophic muscle fasciculus in right ventricular outtract, without VSD. Thus, diagnostic accuracy rate of ultnasonic pused Doppler was 93.3%.These preliminary studies suggest that ultrasonic pulsed Doppler technique is a useful noninvasive method for the diagnosis of VSD, and it is especially useful for post-operative follow-up.