Atrioventricular Conduction Delay in the Second Trimester Measured by Fetal Magnetocardiography

Abstract

Introduction. Fetal AV block in SSA/Ro pregnancies is generally not seen before 18-week gestation and onset is rare after 28-week gestation. If complete AV block appears, it is believed to be irreversible. The purpose of the study was to evaluate precise electrophysiological AV conduction from 18-week gestation onwards. Patients and Methods. 21 fetuses of pregnant women with collagen vascular diseases were included in the study group and 59 healthy fetuses served as controls. In addition to fetal echocardiography, fetal magnetocardiography (fMCG) was used to investigate precise electrophysiological fetal cardiac time intervals (fCTIs). Results. The PR segment (isoelectric segment between the end of the P wave and the start of the QRS complex) was significantly prolonged (P < 0.036 2nd trimester, P < 0.023 3rd trimester) in both trimesters within the study group. In fetuses less than 23-week gestational age, a nearly complete separation was found, where a PR segment of 60 ms or greater completely excluded control fetuses. All other fCTIs did not differ significantly. None of the fetuses progressed to a more advanced heart block. Conclusion. Slight antibody effects in pregnancy, leading to PR segment prolongation, can already be seen from 18-week gestation onwards by fMCG. Serial fetal Doppler echocardiography and additional fMCG can be useful methods to measure early and precise AV conduction time, to achieve best surveillance for these high-risk pregnancies.

Autoimmune-associated Congenital Heart Block

“…It is urgently necessary to define the susceptible populations, from both maternal and fetal aspects. [ 2 15 26 27 28 29 30 31 32 33 34 35 36 37 ] The efficacy of current approaches for preventing the CHB progression in affected fetus and recurrence in subsequent pregnancy as well as other autoimmune-mediated damages is still controversial. The parameters to weigh out the risk and benefit remain to be determined.…”

“…Furthermore, recent studies showed that fMCG can be effectively used in the prenatal diagnosis of atrial bigeminy (conducted and blocked), 2:1 AVB, CAVB, delayed AV conduction, PQ segment prolongation, and different types of long QT syndrome. [ 32 33 34 35 ]…”

Reconstruction of the Human Heart Functional Structure Based On a Few-Channel Magnetocardiogram

“…В настоящее время магнитокардиографы используются для изучения нормальной работы сердца [4] и диагностики его различных заболеваний [5][6][7][8][9][10][11][12][13][14]. При этом, как правило, МКГ-обследования проводят в магнитно-экранированном помещении, ослабляющем внешние электромагнитные помехи от двух до пяти порядков [15,16].…”