Arya Bhawna, Govindan Rathinaswamy, Krishnan Anita, Duplessis Adre, Donofrio Mary T
Division of Cardiology, Seattle Children's Hospital, University of Washington School of Medicine, 4800 Sand Point Way NE, M/S RC.2.820, PO Box 5371, Seattle, WA, 98105, USA,
Pediatr Cardiol. 2015 Jun;36(5):1042-9. doi: 10.1007/s00246-015-1118-4. Epub 2015 Jan 22.
Cardiac rhythm is an essential component of fetal cardiac evaluation. The Monica AN24 is a fetal heart rate monitor that may provide a quick, inexpensive modality for obtaining a noninvasive fetal electrocardiogram (fECG) in a clinical setting. The fECG device has the ability to acquire fECG signals and allow calculation of fetal cardiac time intervals between 16- and 42-week gestational age (GA). We aimed to demonstrate the feasibility of fECG acquisition in a busy fetal cardiology clinic using the Monica fetal heart rate monitor. This is a prospective observational pilot study of fECG acquired from fetuses referred for fetal echocardiography. Recordings were performed for 5-15 min. Maternal signals were attenuated and fECG averaged. fECG and fetal cardiac time intervals (PR, QRS, RR, and QT) were evaluated by two cardiologists independently and inter-observer reliability was assessed using intraclass coefficient (ICC). Sixty fECGs were collected from 50 mothers (mean GA 28.1 ± 6.1). Adequate signal-averaged waveforms were obtained in 20 studies with 259 cardiac cycles. Waveforms could not be obtained between 26 and 30 weeks. Fetal cardiac time intervals were measured and were reproducible for PR (ICC = 0.89; CI 0.77-0.94), QRS (ICC = 0.79; CI 0.51-0.91), and RR (ICC = 0.77; CI 0.53-0.88). QT ICC was poor due to suboptimal T-wave tracings. Acquisition of fECG and measurement of fetal cardiac time intervals is feasible in a clinical setting between 19- and 42-week GA, though tracings are difficult to obtain, especially between 26 and 30 weeks. There was high reliability in fetal cardiac time intervals measurements, except for QT. The device may be useful for assessing atrioventricular/intraventricular conduction in fetuses from 20 to 26 and >30 weeks. Techniques to improve signal acquisition, namely T-wave amplification, are ongoing.
心律是胎儿心脏评估的重要组成部分。Monica AN24是一种胎儿心率监测仪，它可以在临床环境中提供一种快速、廉价的方式来获取无创胎儿心电图（fECG）。fECG设备能够采集fECG信号，并允许计算妊娠16至42周胎龄（GA）之间的胎儿心脏时间间期。我们旨在证明在繁忙的胎儿心脏病诊所使用Monica胎儿心率监测仪采集fECG的可行性。这是一项对因胎儿超声心动图转诊的胎儿进行fECG采集的前瞻性观察性试点研究。记录时间为5至15分钟。对母体信号进行衰减并对fECG进行平均。由两位心脏病专家独立评估fECG和胎儿心脏时间间期（PR、QRS、RR和QT），并使用组内系数（ICC）评估观察者间的可靠性。从50名母亲（平均GA 28.1±6.1）中收集了60份fECG。在20项研究的259个心动周期中获得了足够的信号平均波形。在26至30周之间无法获得波形。测量了胎儿心脏时间间期，PR（ICC = 0.89；CI 0.77 - 0.94）、QRS（ICC = 0.79；CI 0.51 - 0.91）和RR（ICC = 0.77；CI 0.53 - 0.88）具有可重复性。由于T波描记不理想，QT的ICC较差。在妊娠19至42周的临床环境中，采集fECG和测量胎儿心脏时间间期是可行的，尽管波形难以获得，尤其是在26至30周之间。除QT外，胎儿心脏时间间期测量具有高度可靠性。该设备可能有助于评估20至26周和>30周胎儿的房室/心室内传导。正在进行改善信号采集的技术研究，即T波放大。
