Online ISSN: 2187-2988 Print ISSN: 0911-1794
特定非営利活動法人日本小児循環器学会 Japanese Society of Pediatric Cardiology and Cardiac Surgery
Pediatric Cardiology and Cardiac Surgery 35(4): 221-227 (2019)


胎児心不全不整脈の重症度をどう評価するAssessment of the Severity of Heart Failure in Fetuses with Fetal Arrhythmias

雪の聖母会聖マリア病院新生児科Department of Neonatology, St. Mary’s Hospital ◇ Fukuoka, Japan

発行日:2019年11月1日Published: November 1, 2019

胎児不整脈では,心不全が進行すると胎児水腫となり胎内死亡をきたすため,心不全の重症度評価は重要な課題となるが,実際には正確な評価は難しい.通常,胎児心エコー検査で胎児心不全を評価するCVP (cardiovascular profiling)スコアなどで使用されるドプラ血流波形は,不整脈により変化するため評価に使用できない項目が多い.そこで,心拡大の程度や房室弁閉鎖不全の出現,特に僧帽弁閉鎖不全に着目したり,血流波形のVTI (velocity-time integral)による心拍出量の算出で心不全の兆候を検出する.胎児の一般的な全身状態の評価であるBPS (biophysical profiling score)も参考にできる.心拍数との関連では,頻脈性不整脈では,上室頻拍では心拍220回/分以上,心室頻拍では200回/分以上,胎児徐脈性不整脈では心拍55回/分未満が心不全進行の目安となる.しかし,不整脈症例では,頻脈時の頻拍源性心筋症の併発や,徐脈時には心奇形や抗SS-A抗体による心筋炎/心筋症の合併によって心機能が低下してくることが知られており,心拍数のみでは心不全進行の予測は不十分である.複数の指標を合わせて,継時的な経過観察により症例ごとの計測値の変化を評価しながら,管理方法を判断していくことが重要である.

Fetal arrhythmia is a known cause of fetal heart failure that can lead to fetal death. Although assessment of the severity of heart failure is important for managing affected fetuses, it is often difficult in fetuses with arrhythmias. Usually, Doppler waveform, which is accepted in the cardiovascular profiling (CVP) score, is the most useful finding for assessing cardiac function. However, arrhythmia changes the Doppler waveform regardless of the cardiac function, so many of these waveforms may not reveal heart failure. Hence, other fetal echocardiographic findings, such as cardiomegaly assessed by the cardiothoracic area ratio, presence of atrioventricular valve regurgitation, and assessment of cardiac output calculated from the velocity-time integral, are used to detect early signs of cardiac failure. The Biophysical Profiling Score is another method useful for assessing the well-being of affected fetuses. Regarding the fetal heart rate, fetuses often develop heart failure with a fetal heart rate >220 bpm in fetal supraventricular tachycardia, >200 bpm in fetal ventricular tachycardia, and <55 bpm in fetal bradycardia. However, most fetuses with arrhythmia also have cardiac dysfunction, such as tachycardia-induced cardiomyopathy in fetal tachycardia and myocarditis caused by anti-SS-A antibody in fetal bradycardia. Hence, fetal heart rate may not reflect the severity of heart failure in many fetuses. Assessment by combining multiple assessment strategies and sequential follow-up of these findings are essential for assessing heart failure in fetuses with arrhythmias.

Key words: fetal arrhythmias; fetal heart failure; fetal echocardiography; fetal tachycardia; fetal bradycardia

This page was created on 2019-11-20T11:35:40.103+09:00
This page was last modified on 2019-12-16T14:53:23.000+09:00