ABSTRACT
Fetal magnetocardiography (FMCG) is increasingly being used in research and diagnostics of fetal heart function. Currently, FMCG is the only noninvasive procedure available, comparable to postnatal ECG, which can be used to assess cardiac electrophysiology during the second and third trimester of pregnancy. For a reliable evaluation and full clinical acceptance of this new technique, large numbers of patient investigations are required which can only be obtained in multicenter studies. An international standard protocol is needed to allow pooling of sufficient data and to permit the comparison of studies performed in different centers. This article provides recommended standards for FMCG in the fields of data acquisition and data analysis.
Subject(s)
Arrhythmias, Cardiac/diagnosis , Electrocardiography/standards , Fetal Diseases/diagnosis , Prenatal Diagnosis , Female , Heart Defects, Congenital/diagnosis , Humans , Magnetics , PregnancyABSTRACT
OBJECTIVE: Differences in the cardiac excitation cycle between normotrophic and intrauterine growth-restricted fetuses were to be investigated by fetal magnetocardiography (fMCG). STUDY DESIGN: In this study, the time intervals of the fMCG signal in dependence on gestational age were compared between a group of 30 growth-restricted fetuses and 60 normotrophic fetuses by using Spearman's correlation coefficient and two-way analyses of variance. RESULTS: A significantly increasing duration of the P wave and the QRS complex could be observed with advancing gestational age in the normotrophic collective. This prolongation was not evident in the group of growth-restricted fetuses. The QRS complex showed a significant difference between both groups. In regard to the duration of the PR and the QT intervals, neither a distinct increase nor a clear difference between both groups was observable. CONCLUSION: In contrast to the observations in the normally grown fetuses, none of the cardiac time intervals in the group of the growth-restricted fetuses were significantly correlated with gestational age. More especially, the results of the QRS complex could be an indicator of the altered conditions when intrauterine life is complicated by intrauterine growth restriction (IUGR).
Subject(s)
Cardiotocography/methods , Electrocardiography/methods , Fetal Growth Retardation/physiopathology , Fetal Heart/physiology , Magnetics , Adult , Female , Gestational Age , Heart Conduction System/physiology , Humans , Pregnancy , Prenatal Diagnosis/methodsABSTRACT
OBJECTIVES: To investigate the changes of the fetal magnetocardiography (FMCG), a new noninvasive diagnostic tool in the analysis of electrophysiologic changes of the heart, in cases of congenital heart defect (CHD). METHODS: The FMCG was analysed and compared to the postnatal ECG in eight cases of CHD: atrial septal defect ASDII (three cases), a combination of atrioventricular-septal-defect (AVSD) and Tetralogy of Fallot (TOF) (one case ), complete transposition of great arteries (d-TGA) (two cases), coarctation of aorta (COA) (one case), stenosis of the pulmonary artery (PS) and right ventricular hypoplasia (one case). RESULTS: (1) The following FMCG changes were observed: a split R-wave (AVSD/TOF, ASDII), prolongation of QRS complex (COA, PS). (2) The notch of the R-wave could not be observed in the newborn with AVSD/TOF. (3) Neither the fetal FMCG nor the neonatal ECG revealed any changes in the cases of d-TGA. (4) All other neonatal ECGs were corresponding to the FMCG. CONCLUSIONS: The FMCG can unearth changes of the cardiac electrophysiologic activity in the case of CHD. The method provides additional information concerning the effect of a CHD on the cardiac conductory system. As in the neonate, the FMCG changes do not reflect the severity of the CHD. FMCG cannot serve as a primary diagnostic tool in the case of CHD as compared to echocardiography.
Subject(s)
Arrhythmias, Cardiac/diagnosis , Electrocardiography/methods , Fetal Diseases/diagnosis , Heart Defects, Congenital/diagnosis , Prenatal Diagnosis , Adult , Female , Humans , Magnetics , Pregnancy , Reproducibility of ResultsSubject(s)
Academic Medical Centers/standards , Analgesia, Epidural/standards , Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Aspirin/adverse effects , Catheterization , Data Collection , Epinephrine , Humans , Monitoring, Intraoperative , Surveys and Questionnaires , United States , Vasoconstrictor AgentsABSTRACT
OBJECTIVES: To analyse the physiologic development of fetal cardiac time intervals throughout gestation using fetal magnetocardiography (FMCG). METHODS: FMCG data of 163 uncomplicated pregnancies (19th and 42nd gestational week) were analysed. Mean value, standard deviation, minimum and maximum of the duration of the P-wave, the QRS-complex, the PR and the QT-interval were plotted against gestational age. RESULTS: QRS-complex, P wave and QT-interval showed a significant lengthening between the 20th and 42nd gestational week. The mean of the QRS complex raised from 36+/-4.7 ms (week 21-24) up to 48+/-5.2 ms (> or =37th week), (p=0.0001). The mean of the P-wave was between 47+/-5.9 ms (week 21-24) and 53+/-9.5 ms (> or =37th week), (p=0.05) and the mean of the QT-interval was 198+/-18 ms (week 21-24) and increased up to 244+/-23.9 ms (> or =37th week), (p=0.009). The PR-interval did not show a correlation with gestational age. CONCLUSION: FMCG provides sufficient information about all parts of the fetal cardiac conduction system from the 19th gestational week on. It offers the possibility to analyse the shape and the duration of the PQRST-complex.
