Use of time interval histographic output from echo-Doppler to detect left-to-right atrial shunts.

The primary purpose of this study was to attempt to select, by examination of the time interval histogram (TIH) output of a range gated pulsed Doppler (RGPD), all children with left-to-right shunt at the atrial level from a pool of 57 children. Fifty-four of the children had various forms of acyanostic cardiac disease. A secondary purpose was to identify any associated lesions in those children with atrial defects. Examiners were unfamiliar with the children and their diagnoses. Results were interpreted independently by two examiners. Detection of diastolic TIH dispersion was used when studying the right atrial outflow tract to separate children with atrial left-to-right shunts from control children. All controls were judged negative by this technique, and 13 of 14 children with atrial shunts were detected by both examiners; the 14th was detected by one examiner. Of a total of 308 TIH decisions on the atrial shunt group, 298 were made identically by both examiners for a 97.7% agreement, demonstrating the objectivity of the method. This study demonstrated the usefulness of the TIH evaluation, indicating that continued investigation and equipment improvements are warranted.