UTERINE ELECTROMYOGRAPHY - A CRITICAL-REVIEW

On the basis of a literature review, this work summarizes uterine anim al and human electromyographic information obtained at cellular, myome trial, and abdominal levels during gestation and parturition. We show that both internal and external electromyograms occur in phase with in trauterine pressure increase and exhibit similar spectra, including a slow wave (0.01 < frequency < 0.03 Hz) probably because of mechanical artifacts and a fast wave whose frequency content can be subdivided in to a low-frequency band always present in every contraction and a high -frequency band related to efficient parturition contractions. Applica tion of classic spectral techniques to electromyogram envelopes has id entified group propagation but not pacemaker areas. However, no time d elay or classic propagation has been demonstrated by applying the same spectral techniques to the electromyogram itself, probably because of the nonlinearity and three-dimensional nature of the propagating proc ess.