Background

Accurate fetal arrhythmia (FA) diagnosis is key for effective management. Currently, FA assessment relies on standard echocardiography-based techniques (M mode and spectral Doppler), which require adequate fetal position and cursor alignment to define temporal relationships of mechanical events. Few data exist on the application of color Doppler tissue imaging (c-DTI) in FA assessment. The aim of this study was to examine the feasibility and clinical applicability of c-DTI in FA assessment in comparison with standard techniques.

Methods

Pregnancies with diagnosed FA were prospectively recruited to undergo c-DTI following fetal echocardiography. Multiple-cycle four-chamber clips in any orientation were recorded (mean frame rate, 180 ± 16 frames/sec). With offline analysis, sample volumes were placed on atrial (A) and ventricular (V) free walls for simultaneous recordings. Atrial and ventricular rates, intervals (for atrial-ventricular conduction and tachyarrhythmia mechanism), and relationships were assessed to decipher FA mechanism. FA diagnosis by c-DTI, conventional echocardiographic techniques, and postnatal electrocardiography and/or Holter monitoring were compared.

Results

FA was assessed by c-DTI in 45 pregnancies at 15 to 39 weeks, including 16 with atrial and/or ventricular ectopic beats; 18 with supraventricular tachyarrhythmias, including ectopic atrial tachycardia in 11, atrioventricular reentrant tachycardia in four, atrial flutter in two, and intermittent atrial flutter and junctional ectopic rhythm in one; three with ventricular tachycardias; and eight with bradycardias or atrioventricular conduction pathology, including five with complete atrioventricular block (AVB), one with first-degree AVB evolving into complete AVB, one with second-degree AVB, and one with sinus bradycardia. After training, FA diagnosis by c-DTI could be made irrespective of fetal orientation within 10 to 15 min. FA diagnosis by c-DTI concurred with standard techniques in 41 cases (91%), with additional findings identified by c-DTI in 10. c-DTI led to new FA diagnoses in four cases (9%) not definable by standard techniques. FA diagnosis by c-DTI was confirmed in all 20 with persistent arrhythmias after birth, including three with new diagnoses defined by c-DTI. c-DTI was particularly helpful in deciphering SVT mechanism (long vs short ventricular-atrial interval) in all 18 cases, whereas standard techniques permitted definition in only half.

Conclusions

c-DTI with offline analysis permits rapid and accurate definition of FA mechanism, providing new information in nearly one-third of affected pregnancies.

中文翻译：

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彩色组织多普勒在胎儿心律不齐评估中的增量效益

背景

准确的胎儿心律失常（FA）诊断是有效管理的关键。当前，FA评估依赖于基于标准超声心动图的技术（M模式和频谱多普勒），该技术需要适当的胎儿位置和光标对齐来定义机械事件的时间关系。关于彩色多普勒组织成像（c-DTI）在FA评估中的应用的数据很少。这项研究的目的是与标准技术相比，检查c-DTI在FA评估中的可行性和临床适用性。

方法

胎儿超声心动图检查前瞻性招募了诊断为FA的孕妇进行c-DTI。记录了任何方向的多周期四腔剪辑（平均帧速率，180±16帧/秒）。通过离线分析，将样品量放置在心房（A）和心室（V）的游离壁上，以便同时进行记录。评估房室速率，间隔（房室传导和心律失常机制）以及相关性，以破译FA机制。比较了通过c-DTI，常规超声心动图技术以及产后心电图和/或动态心电图监测进行的FA诊断。

结果

在15到39周内通过c-DTI对45例孕妇进行FA评估，其中16例伴有心房和/或室性异位搏动。室上性快速性心律失常18例，其中异位性房性心动过速11例，房室折返性心动过速4例，房扑2例，间歇性房扑和交界性异位心律1例; 三例伴室性心动过速；8例有心动过缓或房室传导病理，包括5例完全房室传导阻滞（AVB），1例一级AVB演变为完全性AVB，1例二级AVB和1例窦性心动过缓。训练后，可以在10至15分钟内通过c-DTI进行FA诊断，而与胎儿方向无关。通过c-DTI进行的FA诊断与标准技术相符，共41例（91％），加上c-DTI在10项中发现的其他发现。c-DTI在4例（9％）病例中导致新的FA诊断，这是用标准技术无法确定的。通过c-DTI进行的FA诊断在所有20例出生后持续性心律失常中得到证实，其中三例通过c-DTI进行新的诊断。在所有18例病例中，c-DTI有助于破译SVT机制（长心房间隔与短心室间隔），而标准技术仅允许定义其中一半。

结论

具有离线分析功能的c-DTI可以快速而准确地定义FA机制，从而在近三分之一的受影响孕妇中提供新信息。