Simple method to distinguish the type of fetal premature contraction using arterial Doppler time interval measurements

AIM: The purpose of this study was to establish a simple method to distinguish premature ventricular contractions (PVC) from premature atrial contractions (PAC) using a fetal Doppler ultrasound arterial pulse waveform to measure time intervals between sinus node restarting. METHODS: We retrospectively identified 14 fetuses with premature contraction (8 with PAC, 6 with PVC). We measured two distinct parts of time intervals using an arterial pulsed‐wave Doppler: the two consecutive waveforms just before the premature contraction (2‐V interval) and two consecutive waveforms including the premature contraction (XV interval) to measure time intervals between sinus node restarting. We then evaluated the time difference between the 2‐V and XV intervals in PVC compared to PAC. RESULTS: For PVC, the difference between the 2‐V interval and the XV interval was significantly shorter than that for PAC. A cut‐off point of 33 ms, where a difference ≤33 ms was clearly shown to be associated with a PVC and a difference more than 33 ms signified a PAC was demonstrated. CONCLUSION: The 2‐V and XV interval measurements, used to measure time intervals between sinus node restarting, could easily distinguish PVC from PAC in utero. Therefore, this study could potentially be a feasible and effective method for obstetricians or sonographers to employ usefully.