The short-term effect of smoking on fetal ECG.

BACKGROUND: The number of women who smoke during pregnancy is significant even today. The harmful effects of smoking during pregnancy are well known but there are no data on the effects of smoking on fetal electrocardiography (ECG). The lack of data is in connection with the difficulties of recording fetal ECG through the maternal abdomen. METHOD: Third trimester pregnant women who were not able to give up the harmful passion of smoking despite repeated attempts of persuasion were recruited in the study on voluntary basis. The fetal ECG was recorded non-invasively through the maternal abdomen before, during and after smoking, then the data were processed offline. The electrophysiological measurements were performed by a self developed ECG device, which allowed the examination of the morphological differences in "true-to-form" fetal ECG in addition to studying the variability of fetal heart rate. The study involved nine pregnant women. The observed changes are presented through case studies of those pregnant women who showed the most significant anomalies. RESULTS: Compared with the resting state fetal heart rate was increased during smoking. The short-term variability of fetal heart rate was narrowed, while the mother's heart rate did not change significantly - which was an indication of direct fetal stress. No explicit ischemic signs were detected in fetal ECG during smoking, however, in the increasing period of the fetal heart rate, the T wave morphology changed slightly, then it returned to normal. CONCLUSIONS: Demonstrable by the electrophysiological methods, smoking has a direct effect on fetal cardiac function. The fetal heart rate variability shows a pattern during smoking which is a typical sign of stress conditions among adults. The results may have educational consequences as well. Understanding those, hopefully will help pregnant women give up this harmful addiction.

New Validated Signal-averaging-based Electrocardiography Method to Determine His-ventricle Interval.

BACKGROUND/AIM: The signal-averaging (SA) technique is used to record high-resolution electrocardiograms (HRECGs) showing cardiac micropotentials. We aimed to develop a non-invasive signal-averaging-based portable bedside device to determine His-ventricle interval. PATIENTS AND METHODS: After amplifying the HRECG recordings, signal duration and voltage can be measured up to four decimal precision. To validate our system, comparison of the invasively and non-invasively determined HV intervals has been performed in 20 patients. RESULTS: Our workgroup has developed a system capable of displaying and measuring cardiac micropotentials on storable ECG. Neither related paired-sample T-test (p=0.263) nor Wilcoxon's non-parametric signed ranks test (p=0.245) showed significant deviations of the HV intervals. Furthermore, related paired-sample T-test showed strong correlation (corr=0.910, p<0.001) between HV intervals determined by electrophysiology (EP) and non-invasive measurements. CONCLUSION: Our research group managed to assemble and validate an easy to use device capable of determining HV intervals even under ambulatory conditions.

Noninvasive Recording of True-to-Form Fetal ECG during the Third Trimester of Pregnancy.

Objective. The aim of the study was to develop a complex electrophysiological measurement system (hardware and software) which uses the methods of electrophysiology and provides significant information about the intrauterine status of the fetus, intending to obtain true-to-form, morphologically evaluated fetal ECG from transabdominal maternal lead. Results. The present method contains many novel ideas that allow creating true-to-form noninvasive fetal ECG in the third trimester of the pregnancy in 80% of the cases. Such ideas are the telemetric data collection, the "cleanse" of the real time recording from the maternal ECG, and the use of the cardiotocograph (CTG) that allows identifying the fetal heart events. The advantage of this developed system is that it does not require any qualified staff, because both the extraction of the information from the abdominal recording and the processing of the data are automatic. Discussion. Although the idea of a noninvasive fetal electrocardiography is more than 100 years old still there is no simple, effective, and cheap method available that would enable an extensive use. This developed system can be used in the third trimester of the pregnancy efficiently. It can produce true-to-form fetal ECGs with amplitude less than 10 µV.