Fetal Heart Activity Research Articles

Fetal heart rate monitoring of the dying fetus

The continuous recording of fetal heart action in three patients with retroplacental hematoma is described. One fetus died in utero, another immediately post partum; in the last case, attempts at resuscitation were successful. Blood-gas analyses were also performed. The association of the recordings to the development of serious metabolic acidosis is discussed.

Detection of fetal heart activity during early pregnancy by combined B-scan and Doppler examination: a new application.

Abstract. 99 pregnant women, 5 to 11 weeks, were examined by a combined ultrasonic B‐scan and Doppler method to detect fetal heart activity. The fetus was localized accurately by B‐scanning and the heart activity was detected through the mother's abdominal wall with 100% certainty at eight weeks of pregnancy (menstrual age). The earliest fetal heart activity detected was in a pregnancy which dated 44 days from the last menstrual period. Positive findings were recorded on tape and photographed from the oscilloscope screen.

Amniotic chloride concentrations in twin-pregnancy after intra-amniotic injection of hypertonic saline.

SummaryDuring termination of a twin‐pregnancy by saline injection, for a psychiatric indication 20 per cent saline was injected into one amniotic sac and the chloriede concentration in both amniotic fluids was recorded by separate cannulation of the amniotic cavities. Changes in chloride concentration of the maternal serum and fetal heart activity were continuously observed. The fetus in the treated sac died and was born macerated, whereas the other showed signs of life at the delivery. The results show that the composition of the amniotic fluid may change significantly by paraplacental transfer.

Quantitative evaluation of fetal heart rate patterns: I. Processing methods

Recording of the tachogram during fetal monitoring provides a continuous stream of data. The insight in the fetal heart action obtained with the cardio-tachogram and with the interval histogram can be greatly amplified by second order interval distribution, interval distribution in polar coordinates, histograms of the argument and the modulus, and multi dimensional approximation for the modulus and the argument. These processing methods give the advantage of data reduction and the possibility of quantification of details, whereas trends during the course of time can be detected.

Quantitative evaluation of fetal heart rate patterns: III. Beat-to-Beat arrhythmia

Beat-to-beat arrhythmias of fetal heart action can be hardly analysed with ordinary paper tape recordings of the fetal tachogram. This problem can be circumvented by the use of automatic processing methods by which the irregularity can be quantified and different types of irregularity can be diagnosed. Two patients are discussed. The tentative diagnosis in the first case was wandering pacemaker, and in the second one sino-atrial block.

Fetal hypodynamic cardiac insufficiency in erythroblastosis fetalis

By simultaneous recordings of the fetal electrocardiogram and phonocardiogram, a shortening of the fetal systole duration is shown in severe erythroblastosis fetalis. The shortening of the fetal systole is significant as compared with the duration of the fetal systole in normal fetal heart action and amounts to from 0.06 to 0.1 second. The etiology of this phenomenon is discussed.

Technic and results of routine fetal electrocardiography during pregnancy

The principles on which the routine technic of fetal electrocardiography has been developed are use of the electrocardiographic apparatus without modification, application of electrodes to the extremities only, increase of the amplitude of waves and decrease of the fuzziness of tracings by simple means. The technic of obtaining and interpreting fetal electrocardiograms is described in detail. The difference between the results obtained by use of the usual technic and those obtained by use of special technic is illustrated in Figs. 1 to 3.Seventy fetal electrocardiograms were recorded from 52 patients during the last seventy days of pregnancy. Sixty-one or 87 per cent of the electrocardiograms were positive and 9 or 13 per cent were negative. During the last twenty days of pregnancy 40 out of 44 electrocardiograms or 91 per cent were positive. Between the twenty-first and seventieth day before delivery 21 out of 26 electrocardiograms or 81 per cent were positive. In cases of vertex presentation, during the last twenty days of pregnancy, 94 per cent of the electrocardiograms were positive and, between the twenty-first and seventieth days before delivery, 87 per cent were positive.Besides the usual Leads I, II and III, two more leads were used (right arm—right thigh; left arm—right thigh). The largest number of positive results were obtained in the third lead (46) and in the fifth lead (left arm—right thigh) (45) because they are most favorable in the left vertex position of the fetus which is the most frequent position.Twenty-five per cent of the positive fetal electrocardiograms were positive in only one lead, 31 per cent in two leads, 15 per cent in three leads and 29 per cent in four leads. In the last three weeks before delivery, 38 per cent of the tests were positive in four leads.As an example of the practical value of the fetal electrocardiogram, a case is described and the electrocardiogram is shown in which the fetal heart tones could not be heard through the stethoscope and the electrocardiogram gave evidence of a living fetus fifty-five, forty-three, and thirty-one days before the expected term.Fetal electrocardiography in pregnancy and labor gives objective graphic evidence regarding the viability of the fetus. This is of practical value in doubtful cases in which the older subjective methods, stethoscopic examiantion, and observation of fetal movements fail. By means of the technic presented, the rate, rhythm, and regularity of fetal heart action can be observed in the electrocardiogram. The scientific field of fetal electrocardiography might even be wider. Such a procedure renders possible observation of the fetus objectively under various conditions in pregnancy and labor. The relationship between maternal and fetal heart action can be easily studied.