講演情報
[I-AEPCYIA-2]Usefulness of Fetal Electrocardiogram Monitoring in Evaluating Treatment Indications for Fetal Supraventricular Tachycardia
○Takeshi Ikegawa1, Motoyoshi Kawataki2, Yuki Okada3, Yuki Kamihara3, Michi Kasai3, Hiromi Nagase3, Hiroshi Ishikawa3, Hideaki Ueda1, Yoshitaka Kimura4 (1.Department of Cardiology, Kanagawa Children’s Medical Center, Kanagawa, Japan, 2.Department of Neonatology, Kanagawa Children’s Medical Center, Kanagawa, Japan, 3.Department of Obstetrics, Kanagawa Children’s Medical Center, Kanagawa, Japan, 4.Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, Miyagi, Japan & Department of Obstetrics and Gynecology, South Miyagi Medical Center, Miyagi, Japan)
キーワード：
fetus、electrocardiogram、supraventricular tachycardia
INTRODUCTION:Approximately 41% of fetal supraventricular tachycardia (SVT) cases progress to fetal hydrops, especially when tachycardia is present for >50% of the monitoring time, necessitating consideration of transplacental therapy with antiarrhythmic drugs. Current methods for assessing fetal heart rate, such as delivery monitoring devices, rely on Doppler ultrasound and may fail to accurately count heart rates during extrasystoles or significant tachycardia.
METHODS:We report a case of fetal SVT caused by premature atrial contraction with block, which could not be evaluated via fetal heart rate monitoring using a delivery monitor.
RESULTS:The patient was a 37-year-old woman at 28 weeks’ gestation referred for fetal tachycardia detected during routine examination. Fetal echocardiography (ECG) revealed occasional premature atrial contractions (PAC) with block and SVT, with heart rates of approximately 270 beats per minute during SVT. Despite normal thyroid function and autoimmune disease tests, fetal echocardiography could not consistently assess the frequency of arrhythmias due to the fluctuating nature of the SVT episodes. To improve assessment, fetal ECG monitoring was employed at 29 and 31 weeks gestation. The prolonged ECG allowed for a more accurate measurement of tachycardia frequency. The fetal ECG revealed that SVT accounted for less than 50% of the monitoring time (Figure 1). By 31 weeks, the frequency of SVT was low enough to avoid immediate therapeutic intervention. The mother was discharged at 31 weeks and monitored outpatient, with no further signs of fetal hydrops. She delivered a healthy baby boy at 38 weeks without arrhythmias or cardiac abnormalities.
CONCLUSIONS:The findings suggest that prolonged fetal ECG monitoring is a valuable tool in evaluating the frequency of fetal arrhythmias, offering a less invasive and more accurate alternative to traditional methods, such as Doppler ultrasound and fetal echocardiography. This approach is particularly useful in cases of intermittent tachyarrhythmias where precise frequency data are critical for determining the need for treatment. In this case, prolonged fetal electrocardiogram monitoring was useful in determining the need for fetal therapy.
Figure 1
Analysis and summary of the second fetal echocardiography (ECG) monitoring on the same day at 31 weeks' gestation. The figure shows the change over time in the fetal heart rate (blue line) obtained from the fetal electrocardiogram. The vertical axis represents the heart rate (bpm), and the horizontal axis represents the elapsed time (s). The normal sinus rhythm section is shown in light blue, supraventricular tachycardia (SVT) section in red, premature atrial contraction (PAC) section in yellow, and indistinguishable section due to unclear fetal bioelectrical signals in gray. SVT is 47.7% and does not exceed 50%.
METHODS:We report a case of fetal SVT caused by premature atrial contraction with block, which could not be evaluated via fetal heart rate monitoring using a delivery monitor.
RESULTS:The patient was a 37-year-old woman at 28 weeks’ gestation referred for fetal tachycardia detected during routine examination. Fetal echocardiography (ECG) revealed occasional premature atrial contractions (PAC) with block and SVT, with heart rates of approximately 270 beats per minute during SVT. Despite normal thyroid function and autoimmune disease tests, fetal echocardiography could not consistently assess the frequency of arrhythmias due to the fluctuating nature of the SVT episodes. To improve assessment, fetal ECG monitoring was employed at 29 and 31 weeks gestation. The prolonged ECG allowed for a more accurate measurement of tachycardia frequency. The fetal ECG revealed that SVT accounted for less than 50% of the monitoring time (Figure 1). By 31 weeks, the frequency of SVT was low enough to avoid immediate therapeutic intervention. The mother was discharged at 31 weeks and monitored outpatient, with no further signs of fetal hydrops. She delivered a healthy baby boy at 38 weeks without arrhythmias or cardiac abnormalities.
CONCLUSIONS:The findings suggest that prolonged fetal ECG monitoring is a valuable tool in evaluating the frequency of fetal arrhythmias, offering a less invasive and more accurate alternative to traditional methods, such as Doppler ultrasound and fetal echocardiography. This approach is particularly useful in cases of intermittent tachyarrhythmias where precise frequency data are critical for determining the need for treatment. In this case, prolonged fetal electrocardiogram monitoring was useful in determining the need for fetal therapy.
Figure 1
Analysis and summary of the second fetal echocardiography (ECG) monitoring on the same day at 31 weeks' gestation. The figure shows the change over time in the fetal heart rate (blue line) obtained from the fetal electrocardiogram. The vertical axis represents the heart rate (bpm), and the horizontal axis represents the elapsed time (s). The normal sinus rhythm section is shown in light blue, supraventricular tachycardia (SVT) section in red, premature atrial contraction (PAC) section in yellow, and indistinguishable section due to unclear fetal bioelectrical signals in gray. SVT is 47.7% and does not exceed 50%.
