Abstract
We conducted this investigation to determine the clinical utility of time‐interval histogram (TIH) analysis of the output of the range‐gated pulsed Doppler in children with pulmonary stenosis. The interpreters and performers of the test were kept as blind as possible to the diagnosis. Fourteen children with valvular pulmonary stenosis and 52 control subjects were evaluated. Diagnosis was confirmed by cardiac catheterization in 13 of 14 experimental analyses and 43 of 52 control analyses. The TIH criterion tested was a frequency dispersion greater than 1 cm in vertical amplitude or a dispersion greater than one‐third of the amplitude of the total complex in larger complexes. Both evaluators detected those children with pulmonary stenosis in 13 of 14 instances. Only one examiner detected the abnormality in the other child. Both examiners found pulmonary flow disturbances by TIH evaluation in 16 of 52 controls; one examiner found flow disturbances in 3 other controls. None of these children had a discernible pulmonary valve gradient at catheterization. In most instances the latter flow disturbances represented series effects of disturbed flow. Small numbers of false negative and false positive results occurred, but the results of detection of true pulmonary stenosis were significant (p < 0.0001). This investigation demonstrates the clinical utility of TIH evaluation for detecting pulmonary stenosis.