what is sinusoidal FHR variability associated with?
The sinusoidal pattern is a regular, smooth, undulating from typical of a sine wave that occurs with frequency of two to five cycles per minute and an amplitude range of 5 to 15 bpm. It is also characterized by a stable baseline heart rate of 120 to 160 bpm and absent beat-to-beat variability.The sinusoidal pattern is rare but ominous and is associated with high rates of fetal morbidity and mortality.aseline Fetal heart rate. Baseline FHR is the most common momentary frequency beats per minute (bpm) during a 10-minute segment, excluding periodic changes and periods of marked FHR variability (segments of baseline that differ by more than 25 bpm).