Successful real time transtelephonic transmission of fetal echocardiographic studies

Fetal ultrasound studies performed at an obstetric center may detect cardiac disease and not have pediatric cardiology consultation services immediately available. Real time transtelephonic transmission of studies could speed the consultation process. Therefore, we transmitted previously recorded fetal cardiac ultrasound studies from a remote to a central reading site to assess accuracy of diagnosis. Scans were transmitted via Integrated Services Digital Network telephone lines (384 Kbps) using a commercially available videoconferencing PC. The transmitted resolution was 352 × 240 × 16 bits at a maximum 30 frames/sec. All 24 echocardiograms were recorded (real time) on VS inch video tape (VHS). Two readers were blinded to diagnosis and independently evaluated presence and type of heart disease, rhythm, and chamber enlargement in the absence of structural heart disease. Interpretations were compared to the diagnosis at the time of the initial study. Gestational age at the time of study ranged from 20 to 38 weeks. Heart rates ranged from 115-240 bpm. Diagnoses were: Normal (15), Ectopy/Tachycardia (3), Tetralogy of Fallot (3), Atrioventricular Canal Defect (1), Double Outlet Right Ventricle (1), and Tricuspid Atresia (1). 6/6 patients with structural heart disease, 3/3 patients with ectopy/tachycardia, and 15/15 patients with normal hearts were correctly identified by both readers. In 4/24 studies, inter-reader discrepancies were found regarding pulmonary valve function (atresia vs severe stenosis, absent pulmonary valve vs stenosis) (2), and chamber enlargement in the absence of structural heart disease (2). Qualitatively both readers felt that the presence of a poor acoustic window limited diagnostic accuracy, particularly with regard to confirming the presence of normal anatomy. Real time transtelephonic transmission of fetal echocardiograms is feasible and may be used as a screening tool for congenital heart disease. Prospective transmission of live studies is needed to ascertain if study quality can be improved.