<prompt> Sinusoidal heart rate pattern is seen in:Placenta previaVasa previaBattledore placentaSuccenturiate placenta  <response>: Sinusoidal Pattern:Stable baseline heart rate of 120 to 160 beatsmin with regular oscillations.Amplitude of 5 to 15 beatsmin rarely greater.Long-term variability frequency of 2 to 5 cycles per minute.Fixed or flat short-term variability.Oscillation of the sinusoidal waveform above or below a baseline.Absence of accelerations.Causes of Sinusoidal Pattern:Serious fetal anemia due to Rh-isoimmunisationrupture vasa previa feto maternal hemorrhage twin to twin transfusion.Drugs Meperidine, morphine, alpha prodine and butorphanol.Amnionitis.Fetal distress .Umbilical cord occlusion. 