First, the 2‐V interval was the measurement of the two consecutive regular arterial Doppler flow waves just before the premature beat (Figure (Figure1). ![]() We defined two distinct parts of time intervals measurements in the arterial Doppler spectroscopy. We used the arterial Doppler waveform obtained from the ascending aorta, the main pulmonary artery or the umbilical artery to measure the timing of contractions after the premature beat. We also excluded the cases in which the recorded artery pulse Doppler did not show any PAC or PVC. We excluded the cases of bigeminy of premature contractions, and the cases of blocked PAC. A ProSound F75 Premier (Hitachi, Ltd) ultrasound was used to obtain the fetal ultrasound. In short, the pulsed Doppler recording method was simultaneously applied to the superior vena cava and the ascending aorta to distinguish a PVC from a PAC. We employed both the M‐mode and pulsed‐wave Doppler mode to diagnose of the PAC and PVC as described previously. We reviewed fetal ultrasound records with isolated premature contractions at Kurume University Hospital, Kurume City, Japan, between Januand December 31, 2017. This was a retrospective observational study at a single center. The purpose of this study was to develop a simple method to determine the type of premature contraction using this difference in the arterial flow start time after the premature contraction measured by pulsed‐wave fetal Doppler ultrasound. Whereas with PVC, the sinus node rhythm usually is not reset and the atrial and ventricular contractions that following premature contraction usually are in time with the original sinus rhythm. It is well known that the timing of a sinus atrial contraction following a PAC differs from that following a PVC.Įxtra electrical impulses reset the sinus node rhythm in PAC so that the atrial and ventricular contractions that follow the premature contraction appear earlier than the sinus activity is expected. However, it is often difficult to obtain sufficient imaging with low‐level examination to clearly distinguish PVC from PAC. Or a simultaneous recording of Doppler waveforms in the vein and artery, can show the timing of the atrial and ventricular contractions. M‐mode imaging obtained by placing the beam line through the atrial wall and the other side of the ventricular wall, The simultaneous recording of atrial and ventricular contractions obtained from an M‐mode, or pulsed‐wave Doppler echocardiography is widely used to distinguish between the different types of premature contractions. Hence, it is essential to distinguish PVC from PAC even with a low‐level examination like a fetal ultrasound. ![]() ![]() The American Heart Association guidelines recommend that fetuses with PVC or frequent PAC that occur more than every 3–5 beats on average should have a thorough fetal echocardiogram performed. Premature atrial contractions (PAC) are 10 times more common than premature ventricular contraction. Premature fetal contractions can be observed in 1–3% of all fetuses and are thought to be a relatively benign condition.
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