胎儿心律失常的超声心动图检测及其临床意义

目的 探讨超声心动图检测对胎儿心律失常的诊断价值及临床意义。方法 采用超声心动图对725例胎龄16-41周临床疑诊为心律失常或存在其他异常的胎儿进行检测。结果 共检出胎儿心律失常90例。其中,期前收缩72例(房性期前收缩65例,室性期前收缩7例),心动过缓9例,心动过速6例,2:1房室传导阻滞2例,心房扑动1例。4例心动过缓胎儿并发先天性心血管畸形患者,2例在随访过程中死于宫内(尸体解剖证实为单心室伴肺动脉瓣狭窄1例,心脏横纹肌瘤1例),2例终止妊娠(尸体解剖证实为二尖瓣闭锁1例,共同房室通道1例)。1例胎龄38周心房扑动胎儿经吸氧及严密监护24h后,心律失常无缓解,立即行剖宫产术,出生后应用西地兰后心律转为窦性。其余85例胎儿心律失常均为阵发性,不伴有胎儿心脏形态、结构畸形及胎儿水肿,均足月出生,出生后听诊均未闻及心脏杂音及心律失常。结论 胎儿超声心动图是产前检查胎儿心律失常的可靠的无创性影像技术,其应用有助于早期检出并指导心律失常胎儿的处理。     

Perinatal outcome of fetus with isolated congenital second degree atrioventricular block without maternal anti-SSA/Ro-SSB/La antibodies

OBJECTIVE: We determined the perinatal outcomes of fetuses with isolated congenital second degree atrioventricular block detected in utero and born to mothers seronegative for anti-SSA/Ro-SSB/La antibodies. METHODS: Isolated second degree atrioventricular block was defined as second degree atrioventricular block detected in utero without the accompanying structural cardiac anomaly, tachyarrhythmia, non-conducted premature atrial beats or long QT syndrome. We review our own cases and search from Medline using keywords such as atrioventricular block, arrhythmia, bradycardia and congenital to collect cases of congenital isolated second degree atrioventricular block. RESULTS: Two cases were from our institution and five cases from a Medline search; in total seven cases of isolated second degree atrioventricular block without maternal anti-SSA/Ro-SSB/La antibodies were analyzed. Six of the seven fetal arrhythmias reverted to sinus rhythm by delivery and did not recur during the follow-up period. The prognosis of the fetus with isolated second degree atrioventricular block without maternal anti-SSA/Ro-SSB/La antibodies is better than that of the fetus with maternal anti-SSA/Ro-SSB/La antibodies or the fetus of congenital long QT syndrome with second degree atrioventricular block detected in utero. CONCLUSION: The fetus with isolated congenital second degree atrioventricular block carries a good prognosis in the absence of maternal anti-SSA/Ro-SSB/La antibodies.     

胎儿心律失常的临床意义及预后的研究

目的 总结胎儿心律失常原因，进一步探讨其临床意义及对胎儿预后的影响。方法 采用回顾性分析方法，对26例胎儿心律失常孕妇的情况、胎儿心律失常的临床表现、诊断方法及长期随诊结果进行总结。结果 胎儿心律失常的发生率为0．2％。26例胎儿心律失常中，3例为胎儿心动过速(11．5％)，4例为胎儿心动过缓(15．4％)，19例为不规则胎儿心律(73．1％)；胎儿心律失常平均诊断孕周为35托周(15～41^ 1周)。26例中22例为产前胎心听诊时发现胎儿心律失常；1例为妊娠15周超声检查时发现胎儿心律失常；3例胎心监测发现胎儿心律失常。17例产前进行了胎儿超声心动检查，心脏结构未见异常，其中6例胎儿超声心动检查提示胎儿房性早搏，占35．3％，余未见异常。产后新生儿均存活，随诊24例(92．3％)，16例新生儿进行了超声心动检查，其中2例诊断为先天性心脏病，均为房间膈缺损。先天性心脏病新生儿在心律失常胎儿中发生率为7．7％。结论 大多数心律失常的胎儿预后是好的，心脏畸形的发生率很低。对于持续性心率慢的胎儿，需注意心脏结构异常的存在；对于心律失常胎儿的处理采用期待疗法，根据产科指征决定终止妊娠的方式。     

Placental compliance--inferences from Doppler studies of umbilical blood flow during cardiac arrhythmia

Pulsed Doppler ultrasound was used to investigate human umbilical artery blood flow patterns in three fetuses where cardiac arrhythmias were present, viz., congenital bradycardia, multiple extrasystoles and 'dropped beats'. The impedance to blood flow along these arteries was assessed by the pulsatility index. The results suggest that the placental vascular bed on the fetal side has a high compliance.     

Fetal supraventricular tachycardias: diagnosis and management

In the majority of cases, the diagnosis of an isolated fetal tachyarrhythmia results in a favorable perinatal outcome. Although there is general consensus on the management of fetal extrasystoles, refractory supraventricular tachycardia, and atrial flutter and fibrillation, the optimal approach to supraventricular tachycardia without hemodynamic compromise remains uncertain. The benefits of conservative management without antiarrhythmic therapy must be weighed carefully against the lack of reliable predictors for the development of fetal hydrops and associated neurologic complications.     

Intravenous fetal exchange transfusion before 22 weeks of gestation in early and severe red-cell fetomaternal alloimmunization

OBJECTIVES: To determine the perinatal outcome in severe red-cell fetomaternal alloimmunization. METHODS: Retrospective series of 32 affected fetuses treated with intravenous fetal exchange transfusion (IFET) before 22 weeks of gestation. The main outcome measures were the degree of fetal anemia, fetal transfusions and perinatal outcome. RESULTS: The first IFET was performed at 19.8 +/- 1.8 weeks of gestation. All fetuses were severely anemic and hemoglobin levels were not different between 20 hydropic and 12 nonhydropic fetuses (4.1 +/- 2.5 vs. 5.6 +/- 2.8 g/dl, p=0.33). The initial maternal anti-D level ranged from 4 to 76 microg/l and was not correlated to fetal anemia (r=-0.07). CONCLUSION: The overall perinatal survival rate was 78% compared to a previous perinatal loss rate excluding first pregnancies of 55.5%.     

Analysis of cases with fetal extrasystole coexisting with cardiac and extracardiac pathology

OBJECTIVE: The paper presents a review of cases with fetal extrasystole coexisting with different cardiac and extracardiac pathology. DESIGN: The aim of the study is to analyse the results of echocardiographic examinations of fetuses with premature atrial contractions (PAC) quantitatively significant (bigeminy, trigeminy) or coexisting with other abnormal findings in fetal heart or other extracardiac pathologies. MATERIAL AND METHOD: Selected group of 33 (24%) fetuses from 135 with fetal extrasystole was analyzed. The mean gestational time of diagnosis was 29.2 + 4.1 weeks. RESULTS: Quantitatively significant arrhythmia (bigeminy, trigeminy) was diagnosed in 14 fetuses. Blocked PAC (2:1) occurred in two cases causing fetal bradycardia. Premature atrial extrasystole coexisting with different type of arrhythmias were diagnosed in 10 cases (4 x with SVT, 4 x with sinus bradycardia, 2 x with ventricular extrasystole). Heart defects in the analyzed group with PAC were recognized in two fetuses (1 x d-TGA, 1 x heterotaxy syndrome--common a-v canal). Myocarditis was diagnosed in 3 (9%) cases. From the group of 33 fetuses 6 newborns died (1 x d-TGA, 1 x T18, 1 x myocarditis, 1 x circulatory centralization). Mortality in the analyzed group was 18.2%. CONCLUSION: In cases of fetal arrhythmias echocardiography should be widely applied in order to evaluate the kind of arrhythmia, sufficiency of circulation and coexistence of heart defects, extracardiac malformations or functional abnormalities with arrhythmia in fetal circulation.     

胎儿期心律失常的诊断及其对新生儿预后的影响

目的了解胎儿期心律失常的诊断方法、临床意义及对新生儿预后的影响。方法选择2004年6月至2006年1月于浙江大学医学院附属妇产科医院产前检查中发现胎儿心律失常孕妇57例,分析孕妇病史、胎儿心电图、胎儿超声心动图、妊娠结局。结果胎儿心律失常中胎儿心动过速、胎儿心动过缓和不规则胎儿心律的构成比分别为17.4%、4.3%和78.3%。首次发现胎儿心律失常的孕周及胎儿心律失常的类型与新生儿预后没有显著关联。持续发作心律失常的胎儿,其预后显著差于偶发心律失常的胎儿。经期待疗法,孕期胎儿心率恢复正常的有21例(36.8%),出生后新生儿心率迅速恢复正常的有15例(26.3%),经对症治疗后有14例新生儿恢复正常心率(24.6%)。发现4例(7.0%)胎儿心脏结构异常。59.7%的孕妇合并产科并发症。结论大部分心律失常的胎儿预后良好,在临床上可以密切随访,可在分娩前或出生后恢复正常心率;与胎儿预后不良有关的因素为持续发作心律失常、胎儿伴有水肿。     

Management strategy for fetal tachycardia

OBJECTIVE: To develop a management strategy for fetal tachycardia. METHODS: Forty-four fetuses (20-40 weeks' gestation) with nonsinus tachycardia were divided into three groups based on duration of tachycardia and degree of heart failure. Fetuses with intermittent tachycardia were treated expectantly. Fetuses with sustained tachycardia were treated with transplacental antiarrhythmic agents alone if heart failure was mild to moderate, and with direct intramuscular therapy if heart failure was severe. Degree of heart failure was determined by echocardiographic variables of ventricular function, atrioventricular valve insufficiency, and hydrops. Fetal well-being and response to treatment were evaluated by daily heart rate surveillance and frequent fetal echocardiograms and ultrasounds. RESULTS: Fifteen fetuses with intermittent tachycardia (n = 15, group 1) did not progress to sustained tachycardia or heart failure. Fetuses with sustained tachycardia and mild-to-moderate heart failure (n = 14, group 2) were cardioverted or rate controlled with transplacental agents (n = 9); three term fetuses were delivered electively without treatment and two progressed to severe heart failure and were treated in group 3. Seventeen fetuses (15 initially, two progressing) with severe heart failure were cardioverted (in 0. 25-21 days; mean 4.3 days) with fetal intramuscular plus transplacental antiarrhythmic therapy (group 3). Overall, 43 of 44 fetuses were delivered at 32 to 41 (mean 37) weeks with minimal morbidity and a mortality rate of 2.2% (95% confidence interval 0. 06%, 12.0%). CONCLUSION: Perinatal mortality and morbidity were low after following a management strategy based on duration of tachycardia, degree of heart failure, and biophysical profile combined with vigilant ongoing fetal surveillance.     

Doppler echocardiography for managing fetal cardiac arrhythmia

The successful management of fetal arrhythmias is contingent on an accurate diagnosis of arrhythmia and its effects on fetal well-being. Regardless of the rate (tachycardia or bradycardia) or rhythm (regular or irregular), the diagnosis of arrhythmia by Doppler echocardiography is based on the atrioventricular relationship and the atrial and ventricular rates. Fetal well-being at the time of diagnosis and during treatment can be assessed by Doppler flow patterns in the fetal systemic veins and atrioventricular valves. Information from Doppler echocardiography will distinguish those fetuses that can be conservatively managed from those that would benefit from in-utero pharmacotherapy.     

Fetal bradycardia in the first trimester: an unusual presentation of atrial extrasystoles

We report a fetus with fetal bradycardia at 13 weeks of gestation secondary to atrial extrasystoles. The fetus subsequently developed paroxysmal supraventricular tachycardia and hydrops fetalis. The cardiac arrhythmia recovered spontaneously without any medical intervention. This case illustrates that atrial ectopic beats can present in the first trimester with fetal bradycardia. Rapidly evolving hydrops fetalis secondary to supraventricular tachycardia can develop, warranting close monitoring with weekly heart rate assessment. Fetal bradycardia secondary to atrial extrasystole should be differentiated from first trimester sinus bradycardia and those associated with major structural cardiac abnormality, which have a high fetal loss rate.     

Echocardiographic detection of fetal cardiac arrhythmias]

Using real-time directed M-mode and Doppler echocardiography we identified cardiac arrhythmias in 10 fetuses. One had signal tachycardia, one bradycardia, 5 supraventricular premature contractions, and 2 ventricular premature contractions (VPC), which were all self-limited. The diagnosis of VPC in one case was based on premature ending of foramen ovale flap's 2 nd wave on M-mode recording. All cases carried a favorable prognosis except the one with VPC who had a small ventricular septal defect overlooked prenatally. The 10 th case had II degrees atrioventricular block complicated by heart failure and died in utero. This study showed that most arrhythmias can be detected antenatally by analysing atrioventricular contraction sequences. It also proved that the characteristic M-mode pattern of foramen ovale flap is of value in evaluating the types of arrhythmias.     

Natriuretic peptides in the pathogenesis of cardiac dysfunction in the recipient fetus of twin-twin transfusion syndrome.

OBJECTIVE: Although serial amnioreduction has substantially improved the prognosis of twin-twin transfusion syndrome, the majority of recipient twins develop cardiac dysfunction in utero and some have structural abnormalities in the neonatal period. The mechanism of cardiac dysfunction is unclear. To test the hypothesis that this occurs as a result of preload or pressure overload, we determined atrial natriuretic peptide and brain natriuretic peptide levels and their association with endothelin-1 in monochorionic pregnancies with or without chronic twin-twin transfusion syndrome. PATIENTS AND METHODS: Matched maternal and fetal blood samples were obtained in utero from monochorial twin pregnancies complicated with (n = 14) and without twin-twin transfusion syndrome (n = 6). Serial fetal echocardiography assessment included cardiac anatomy, chamber size, cardiothoracic ratio, ventricular thickness, and the presence and severity of atrioventricular valve regurgitation. Postnatal echocardiograms were obtained on the surviving twins. The plasma levels of atrial natriuretic peptide, brain natriuretic peptide, and endothelin-1 were measured by use of radio-immunoassay. RESULTS: Levels of fetal atrial natriuretic peptide (P <.001), brain natriuretic peptide (P <.001), and endothelin-1 (P <.001) in the recipient fetuses were higher than in donor twins. Fetal concentrations of atrial natriuretic peptide, brain natriuretic peptide, and endothelin-1 in the donor twins were similar to those concentrations in twins that did not have twin-twin transfusion syndrome. Fetal brain natriuretic peptide (P <.01) and endothelin-1 (P <.01) levels were significantly higher in the recipient fetuses when compared to those without severe cardiac dysfunction. A significant positive correlation was present between levels of fetal brain natriuretic peptide and endothelin-1 (y = 230.9 LOG(x) - 264.1, r =.82; P <.01). In contrast, there was no association between levels of fetal atrial natriuretic peptide and the severity of cardiac dysfunction, or with levels of fetal brain natriuretic peptide and endothelin-1. CONCLUSION: Fetal natriuretic peptide levels were higher in the recipient twins than the co-twins, and the severity of cardiac dysfunction was related to levels of brain natriuretic peptide. These data, thereby, suggest that brain natriuretic peptide is a sensitive surrogate biochemical marker of cardiac dysfunction in the recipient twin.     

Prenatal diagnosis of arrhythmias and conduction disturbances

OBJECTIVES AND DESIGN: Cardiac arrhythmias are one of the most frequent indications for the fetal echocardiographic assessment. The objective of this work is to present our own results of diagnosing and treating the fetuses with arrhythmias. MATERIALS AND METHODS: The 1485 prenatal echocardiographic examinations were performed in 1302 fetuses. The 109 of fetuses suffered from arrhythmias. RESULTS: 68 fetuses (62.8%) in the analysed group presented with arrhythmias in the form of extra-systoles, 19 fetuses (17.4%) with tachycardia and 22 (20.2%) with a complete atrioventricular block. CONCLUSIONS: We concluded, that arrhythmias can be diagnosed precisely in the early prenatal period, which enables the introduction of the adequate pharmacological treatment and the coexistence of the fetal complete a-v block and structural heart defect in a fetus is associated with poor prognosis.     

Arrhythmias in perinatal period and neonatal outcome--analysis of own experiences

OBJECTIVE: The paper presents review of different kinds of fetal arrhythmias, diagnosed in our centres. DESIGN: The aim of our study was to analyse results of echocardiographic examinations of 141 fetuses with diagnosed arrhythmias referred for fetal cardiac examination in years VI. 1996-V. 2001 and neonatal outcome. RESULTS: Premature contractions were recognised in 113 (80%) fetuses, tachyarrhythmias in 7 (5%) cases and complete atrioventricular block in 5 (4%). Heart defects were diagnosed in three cases. Three fetuses developed congestive heart failure (2x SVT, 1x HLHS + block a-v III*). From all group 6 newborns died. CONCLUSION: In case of fetal arrhythmias echocardiography should be widely applied in order to evaluate the kind of arrhythmia, sufficiency of circulation and coexistence of heart defects or functional abnormalities with arrhythmia in fetal circulation.     

Fetal complete heart block: antenatal diagnosis, significance and management

Complete heart block was diagnosed prenatally in 21 fetuses. Associated structural cardiac defects were present in 18 fetuses, in particular complete atrioventricular canal with atrial isomerism (5 cases), and 'corrected' transposition of the great arteries (4 cases). Maternal systemic lupus erythematosus was proved in only one case. In 11 fetuses, intra-uterine congestive heart failure with the signs of non-immune hydrops fetalis occurred. In all 11 fetuses, the hydrops was associated with a cardiac defect, in particular complete atrioventricular canal with atrial isomerism in 5 cases. A review of the literature confirms that only the association of complete heart block and cardiac malformation can cause intra-uterine congestive heart failure, whereas in the case of fetal complete heart block without cardiac malformation or with prenatally hemodynamically insignificant cardiac malformation, congestive heart failure is rare. Only 30% of newborns with complete heart block have associated cardiac malformations. In our series, however, 86% of the fetuses with complete heart block had cardiac malformations. The most important reason for this percentage discrepancy is that almost all fetuses with associated severe cardiac defects, in particular atrioventricular canal defects, develop heart failure which frequently results in prenatal death. Thus, fetal deaths are not included in pediatric statistics. Nevertheless, fetuses with isolated complete heart block generally do not develop heart failure and in almost all of the cases are born alive.     

Fetal dysrhythmias

Fetal cardiac dysrhythmias are potentially life-threatening conditions. However, intermittent extrasystoles, which are frequently encountered in clinical practice, do not require treatment. Sustained forms of brady- and tachyarrhythmias might require fetal intervention. Fetal echocardiography is essential not only to establish the diagnosis but also to monitor fetal response to therapy. In the last decade, improvements in ultrasound methodology and new diagnostic tools have contributed to better diagnostic accuracy and to a greater understanding of the electrophysiological mechanisms involved in fetal cardiac dysrhythmias. The most common form of supraventricular tachycardia - that caused by an atrioventricular re-entry circuit - should be differentiated from other forms of tachyarrhythmias, such as atrial flutter and atrial ectopic tachycardia. Ventricular tachycardia is rare in the fetus. Sustained tachycardias, intermittent or not, might be associated with the development of congestive heart failure and hydrops fetalis. Prompt treatment with either anti-arrhythmic drugs or delivery must be considered. Persistent fetal bradycardias associated with complete heart block are also potentially dangerous, whereas bradyarrhythmia due to blocked ectopy is well tolerated in pregnancy. Heart block can be associated with maternal anti-Ro/La autoantibodies or develop in fetuses with left atrial isomerism or with malformations involving the atrioventricular junction. The treatment of fetuses with immune-mediated heart block remains debatable. The use of antenatal steroid therapy is not widely accepted and there is concern over the risks and benefits of its use in the fetus. Direct fetal cardiac pacing has rarely been attempted.     

Outcome for fetuses with prenatally detected congenital heart disease and cardiac arrhythmias in Taiwan.

BACKGROUND/PURPOSE: Outcome for fetuses with prenatally detected congenital heart disease (CHD) and/or cardiac arrhythmias is important for prenatal counseling and perinatal management; however, there exists little literature regarding the outcome for CHD diagnosed in utero in Taiwan. Therefore, we attempted to investigate the outcome for fetuses with CHD and/or cardiac arrhythmias diagnosed prenatally at a tertiary care medical center in Taiwan. METHODS: Between January 1995 and December 2000, 339 patients referred to the National Taiwan University Hospital for fetal echocardiography were included in this study. Medical records were reviewed retrospectively to determine the salient clinical characteristics for all fetuses. RESULTS: CHD was found in 103 fetuses. Gestational age at diagnosis ranged from 17 to 40 weeks; in 37 cases (35.9%) the diagnosis was made before 24 weeks. Mean gestational age at diagnosis was 27.8 weeks. Of the 103 cases, 15 fetuses (14.6%) had major extra cardiac malformations and 15 fetuses (14.6%) had chromosomal abnormalities (five had both) and 30 pregnancies (29.1%) were terminated. Of the remaining 73 pregnancies, three (4.1%) of the fetuses died in utero and 28 (38.4%) postnatally, with 42 (57.5%) surviving. The mortality rates were both 60% in cases with extracardiac or chromosomal anomalies. Arrhythmias were identified in 25, and two pregnancies involving hydrops fetalis were terminated. Of the remaining 23 continued pregnancies, two (8.7%) with long QT syndrome expired postnatally. CONCLUSION: Outcome for fetuses with prenatally detected CHD remains poor, with the prognosis negatively influenced by the presence of complex heart defects as well as extracardiac and chromosomal anomalies. However, prognosis is good for fetuses with cardiac arrhythmia, except with long QT syndrome or hydrops fetalis.     

Fetal hematocrit decrease after repeated intravascular transfusions in alloimmunized pregnancies

Background The aim of this study is to evaluate the fetal hematocrit (Hct) decrease along repeated intravascular intrauterine fetal transfusions (IUTs) and test the hypothesis that, after consecutive IUTs, there is a lower Hct drop off. Methods From July 1996 to June 2006, pregnancies submitted to IUT for fetal hemolytic anemia treatment had their data assessed. The daily rate of decrease in fetal Hct was calculated by dividing the difference between the posttransfusion Hct of the previous IUT and the pretransfusion Hct of the current IUT, by the number of days between the transfusions. Fetuses with other abnormalities or submitted to intraperitoneal transfusions were excluded. Results Eighty-one women were submitted to IUT during the alluded period, ensuing 296 intrauterine transfusions. The perinatal survival was 89.9% (n = 80), with 92.0% (n = 69) of nonhydropic fetuses survival. Hydropic fetuses showed higher hematocrit drop off than nonhydropic ones (P < 0.01). Compared to the interval between the first and second IUT, the daily fetal Hct decline was lower after the third one (P < 0.05). Stratifying by the presence of hydrops, nonhydropic fetuses showed a smaller decrease at the third and fourth intervals (P < 0.01 and P < 0.05, respectively). Among hydropic fetuses, there is a trend of smaller Hct decrease along successive IUTs (interval 3, P = 0.08; interval 4, P = 0.07; and interval 5, P = 0.10). Conclusions Following some IUTs, fetal hematocrit decrease is lower and larger intervals between the transfusions could be accomplished. Multicenter studies should investigate an algorithm for timing subsequent IUTs, considering Doppler values, estimated fetal hematocrit decline and other parameters.     

Evaluation of fetal cardiac dysrhythmias with two-dimensional, M-mode, and pulsed Doppler ultrasonography

Forty-three patients with fetal cardiac dysrhythmia were referred to a tertiary ultrasound department for further evaluation. The patients were subdivided according to the type of dysrhythmia diagnosed. All patients with irregular fetal heart rate had a good perinatal outcome. Of the six patients with fetal tachycardia, two required in utero therapy with maternal digoxin, and one of these fetuses had a cardiac tumor. The eleven patients with fetal bradycardia had the worst perinatal outcome, with four deaths occurring. The results suggest that all patients with fetal tachycardia or bradycardia should have a complete fetal cardiac assessment in a center experienced with the management of such cases.