SIMULTANEOUS DOPPLER RECORDING OF THE PULMONARY-ARTERY AND VEIN - A NEW TECHNIQUE FOR THE EVALUATION OF A FETAL ARRHYTHMIA

We describe a new technique to evaluate cardiac rhythm using color and pulsed Doppler ultrasonography to identify and record pulmonary arter ial and venous waveforms. Fifty fetuses were examined during the secon d and third trimesters of pregnancy. Simultaneous pulsed Doppler recor ding of the pulmonary artery and vein was obtained in 100% of fetuses between 15 and 40 weeks' gestation. Atrial systole was identified from the pulmonary vein and was manifested by an interruption of venous fl ow. Ventricular systole was manifested by a sharp peak that returned t oward the baseline before it continued through the duration of systole as a lower-velocity waveform. This technique has the following advant ages: (1) the lung parenchyma is easily accessible, irrespective of fe tal position; (2) the pulmonary arteries and veins are adjacent to eac h other as they enter and exit the lung, thus making it easy to simult aneously obtain Doppler recordings of these vessels; (3) the pulsed Do ppler waveform has an appearance similar to an electrocardiogram.