Lozynska N. Ultrasound diagnosis of cardiac rhythm disorders in a fetus and assessment of their influence on hemodynamics

The dissertation represents the solution of an important problem for ultrasound differential diagnostic, obstetrics, prenatal and pediatric cardiology. It consists in improvement of ultrasound differential diagnosis of fetal heart rhythm disturbances and assessment of severity of hemodynamic complications for optimization of antenatal care. Reports of 2073 ultrasound examinations of fetal heart from 1996 to 2016 were retrospectively studied and 213 diagnosed cases of fetal arrhythmias were analyzed. All the examinations were carried out according to the general protocol. The evaluation of the fetal heart anatomy was based on segmental analysis. The rhythm assessment was performed by reconstructing the fetal EGC using ultrasound techniques and foreseeing the determination of the heart rate of the fetus, atrioventricular ratio, duration and ratio of cardiac cycle intervals. To determine hemodynamic complications, a scoring scale was created. For the statistical processing of the obtained results, all the subjects were divided into groups: by the age of pregnant women and by the term of pregnancy. All arrhythmias were divided into three main groups: irregular rhythm, bradyarrhythmia, tachyarrhythmia, and in each group of arrhythmias, subgroups were identified, according to the types of detected arrhythmias. Also, all arrhythmias were divided according to the duration, clinical significance and a degree of hemodynamic complications. Based on the obtained findings, the prognostic significance of the fetal arrhythmias was determined. The clinical and prognostic value of different types of fetal arrhythmias in perinatal period has been determined as results of a long-term study. In order to improve the diagnosis of fetal arrhythmias, a thorough analysis of ultrasound techniques has been performed, and algorithms of differential diagnosis of fetal arrhythmias have been proposed. According to the results of the study, a practical set of ultrasound indicators for detection and assessment the severity of hemodynamic complications caused by fetal arrhythmia has been proposed. Algorithms of dynamic observation by the fetuses depending on the gestational age at the time of diagnosis of fetal arrhythmia, type of arrhythmia, concomitant pathology and available hemodynamic complications have been developed. The relevance of prenatal echocardiography in the course of dynamic observation of the fetal condition in the prenatal period has been shown. The evaluation of the treatment options for various types of the fetal arrhythmias have been carried out. According to the results of the study, the effectiveness of the drug treatment of the fetal tachyarrhythmias in the prenatal period has been shown. Practical recommendations for perinatal tactics of the antenatal care depending on the clinical and prognostic value of detected fetal arrhythmia have been prepared.