Management outcome and follow-up of fetal tachycardia

Pharmacological Management of Cardiac Arrhythmias in the Fetal and Neonatal Periods: A Scientific Statement From the American Heart Association: Endorsed by the Pediatric & Congenital Electrophysiology Society (PACES)

Disorders of the cardiac rhythm may occur in both the fetus and neonate. Because of the immature myocardium, the hemodynamic consequences of either bradyarrhythmias or tachyarrhythmias may be far more significant than in mature physiological states. Treatment options are limited in the fetus and neonate because of limited vascular access, patient size, and the significant risk/benefit ratio of any intervention. In addition, exposure of the fetus or neonate to either persistent arrhythmias or antiarrhythmic medications may have yet-to-be-determined long-term developmental consequences. This scientific statement discusses the mechanism of arrhythmias, pharmacological treatment options, and distinct aspects of pharmacokinetics for the fetus and neonate. From the available current data, subjects of apparent consistency/consensus are presented, as well as future directions for research in terms of aspects of care for which evidence has not been established.

Clinical utility of repeat fetal echocardiography in congenital heart disease

OBJECTIVES

To investigate the utility of repeat fetal echocardiography (FE) following a diagnosis of structural congenital heart disease (CHD) on the initial FE. We evaluated how often changes in management and counseling occurred based on subsequent FE findings and sought to determine which types of CHD were more likely to have changes in management and/or counseling based on repeat FE.

METHODS

This was a retrospective review of all patients who presented to our center between January 2012 and January 2019 and who had more than one FE performed for structural CHD. We reviewed consultation notes to determine whether management or counseling had changed based on FE findings at follow-up visits. Management variables included a change in location or mode of delivery, plan for atrial septostomy, initiation of prostaglandin infusion, umbilical line placement and planned admission location (nursery vs neonatal intensive care unit). We defined a counseling change as any of the above changes in management as well as any meaningful refinements in the cardiac diagnosis that led to a change in the overall prognosis or future management. Initial diagnoses were grouped into anatomically/hemodynamically relevant subgroups. Fisher's exact test was used to assess the relationship between the initial diagnosis and changes in management. Post-hoc pairwise comparisons were performed using Dunnett's test.

RESULTS

Between January 2012 and January 2019, 267 patients underwent 534 follow-up FE assessments performed for structural CHD. Management change based on repeat FE occurred in 41/267 (15.4%) cases. A change in management was associated with the diagnosis made at the initial visit (P < 0.001). The proportion of cases with a management change was highest among those with an initial diagnosis of pulmonary valve abnormality/non-critical pulmonary stenosis (4/11 (36.4%)), followed by balanced atrioventricular canal (AVC) defect (5/17 (29.4%)) and left ventricular outflow tract obstruction/aortic valve abnormality or coarctation/interrupted aortic arch (19/68 (27.9%)). No management change occurred in fetuses diagnosed with isolated ventricular septal defect (VSD), truncus arteriosus, pulmonary vein anomaly or isolated arch sidedness/branching abnormality. Compared to those with a VSD, management was significantly more likely to be changed in fetuses with a balanced AVC defect (P = 0.025) and left heart lesions (P = 0.002). Right heart lesions showed a trend towards an increased incidence of management change (P = 0.05). A counseling change based on repeat FE occurred in 108/267 (40.4%) cases. The proportion of cases with a counseling change was highest among those with an initial diagnosis of pulmonary valve abnormality/non-critical pulmonary stenosis (8/11 (72.7%)) and hypoplastic left heart syndrome/critical aortic stenosis (5/9 (55.6%)).

CONCLUSIONS

The clinical utility of follow-up FE is associated with the type of CHD diagnosed. Follow-up FE led to changes in management in several types of CHD, most commonly in cases with an initial diagnosis of right and left outflow obstructive lesions and balanced AVC defect. When developing programmatic protocols for the frequency of FE assessments, the type of CHD should be a major determinant, but additional studies are required to reach a consensus on how often serial FE should be performed for each type of CHD. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

A Rare and Challenging Case of Refractory Fetal Supraventricular Tachycardia

Fetal supraventricular tachycardia can be difficult to manage and offers a challenging treatment course, particularly in refractory cases. The treatment course must balance maternal well-being with the health status of the fetus, all while racing against possible progression to hydrops fetalis or permanent cardiac dysfunction. We describe a case of fetal supraventricular tachycardia that demonstrates many of these concepts, as well as the importance of utilizing several treatment pathways in refractory cases.

Fetal Arrhythmia Diagnosis and Pharmacologic Management

One of the most successful achievements of fetal intervention is the pharmacologic management of fetal arrhythmias. This management usually takes place during the second or third trimester. While most arrhythmias in the fetus are benign, both tachy‐ and bradyarrhythmias can lead to fetal hydrops or cardiac dysfunction and require treatment under certain conditions. This review will highlight precise diagnosis by fetal echocardiography and magnetocardiography, the 2 primary means of diagnosing fetuses with arrhythmia. Additionally, transient or hidden arrhythmias such as bundle branch block, QT prolongation, and torsades de pointes, which can lead to cardiomyopathy and sudden unexplained death in the fetus, may also need pharmacologic treatment. The review will address the types of drug therapies; current knowledge of drug usage, efficacy, and precautions; and the transition to neonatal treatments when indicated. Finally, we will highlight new assessments, including the role of the nurse in the care of fetal arrhythmias. The prognosis for the human fetus with arrhythmias continues to improve as we expand our ability to provide intensive care unit–like monitoring, to better understand drug treatments, to optimize subsequent pregnancy monitoring, to effectively predict timing for delivery, and to follow up these conditions into the neonatal period and into childhood. Coordinated initiatives that facilitate clinical fetal research are needed to address gaps in knowledge and to facilitate fetal drug and device development.

Fetal Atrial Flutter Associated with Atrial Septal Aneurysm

Objective: To provide evidence that fetal atrial flutter (AF) caused by atrial septal aneurysm (ASA) can be completely cured by delivery. Methods: Cases series of three fetuses with ASA complicated by AF in late gestation, including hydrops fetalis in one case, were collected and completely followed up. Results: AF in all cases completely disappeared shortly after birth. New insights gained from this study are as follows: (1) PACs or bigeminy associated with ASA can progressively change to AF. (2) AF associated with ASA can cause hydrops fetalis and intrauterine treatment is needed; however, delivery is the definitive treatment. (3) AF associated with ASA completely resolves after birth. This is probably associated with changes in the circulation after birth, with no more blood flow crossing the foramen ovale and no turbulent flow in the ASA with reversal to hit the right atrial wall, activating ectopic pacemakers. Conclusions: This report may have clinical impact because it provides evidence that (1) in case of AF associated with ASA, the prognosis is much better than other causes and delivery should be strongly considered. (2) Fetuses diagnosed with AF should always be checked for the presence of ASA. (3) PAC/bigeminy related to ASA, different from isolated PAC, needs close follow-up for the development of SVT and AF. (4) Fetuses remote from term can benefit from intrauterine treatment to avoid hydrops fetalis, and to prolong gestation for maturity, early delivery is recommended once lung maturity is confirmed.

Efficacy and Safety of Various First-Line Therapeutic Strategies for Fetal Tachycardias: A Network Meta-Analysis and Systematic Review

Background: Fetal arrhythmias are common cardiac abnormalities associated with high mortality due to ventricular dysfunction and heart failure, particularly when accompanied by hydrops. Although several types of common fetal tachycardias have been relatively identified medications, such as digoxin, flecainide, and sotalol, there is no first-line drug treatment protocol established for the treatment of various types of fetal tachycardias.

Methods: We conducted a network meta-analysis using a Bayesian hierarchical framework to obtain a model for integrating both direct and indirect evidence. All tachycardia types (Total group), supraventricular tachycardia (SVT subgroup), atrial flutter (AF subgroup), hydrops subgroup, and non-hydrops subgroup fetuses were analyzed, and five first-line regimens were ranked according to treatment outcomes: digoxin monotherapy (D), flecainide monotherapy (F), sotalol monotherapy (S), digoxin plus flecainide combination therapy (DF), and digoxin plus sotalol combination therapy (DS). Effectiveness and safety were determined according to the cardioversion rate and intrauterine death rate.

Results: The pooled data indicated that DF combination therapy was always superior to D monotherapy, regardless of the tachycardia type or the presence of hydrops: Total, 2.44 (95% CrI: 1.59, 3.52); SVT, 2.77 (95% CrI: 1.59, 4.07); AF, 67.85 (95% CrI: 14.25, 168.68); hydrops, 6.03 (95% CrI: 2.54, 10.68); and non-hydrops, 5.06 (95% CrI: 1.87, 9.88). DF and F had a similar effect on control of fetal tachycardias. No significant differences were observed when comparing S, DS with D therapies across the subgroup analyses for the SVT, hydrops, and non-hydrops groups. No significant differences in mortality risks were among the various treatment regimens for the total group. And no significant differences were found in rates of intrauterine death rates at the same cardioversion amount.

Conclusion The flecainide monotherapy and combination of digoxin and flecainide should be considered the most superior therapeutic strategies for fetal tachycardia.

Systematic Review Registration: (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=288997), identifier (288997).

Evaluation of Clinical Course and Maintenance Drug Treatment of Supraventricular Tachycardia in Children During the First Years of Life. A Cohort Study from Eastern Germany

Supraventricular tachycardia (SVT) is considered the most common cause of arrhythmia in children and infants. Regarding the likelihood of a spontaneous resolution of SVTs during the first years of life, drug treatment aims to bridge the time until children 'grow out' out of the arrhythmia. The choice of antiarrhythmic agents and the planning of maintenance therapy are mainly based on clinical experience and retrospective single- and multi-institutional analyses and databases from all over the world approaching differently to this topic. The current study aimed to evaluate the clinical course, pharmacological treatment strategies, and constellations of risk for recurrences in the management of SVTs in children aged 3 < years. The database of the Heart Center Leipzig, Department of Pediatric cardiology, was searched for pediatric patients aged < 3 years with a clinically documented SVT between 2000 and 2019 that received pharmacologic treatment. Patients with complex congenital heart disease or arrhythmias following cardiac surgery were excluded. 69 patients were included. Pharmacologic treatment, follow-up schedule, recurrences, outcomes, and risk factors for complicated courses are reported. Drug therapy of SVTs in young children remains a controversial topic with heterogeneous treatment and follow-up strategies applied. Risk factors for recurrences and/or stubborn clinical courses are difficult rhythm control with 3 or more antiarrhythmic drugs, ectopic atrial tachycardias, and a first occurrence of the SVT in the fetal period. Prospective studies are needed to sufficiently evaluate optimal treatment strategies.

Association of Fetal Atrial Flutter with Neonatal Atrioventricular Re-entry Tachycardia Involving Accessory Pathway: A Link to be Remembered

To investigate prenatal and postnatal outcomes of atrial flutter and its association with the development of a second tachycardia, following restoration of sinus rhythm, in the fetus or newborn. This study is a retrospective review of all fetuses that presented with atrial flutter from January 2001 to December 2019 at the University Hospital of Wales, Cardiff, UK. The specific type of arrhythmia, its time of appearance and clinical characteristics, echocardiographic findings, medical management, and postnatal outcomes were evaluated. Sixteen fetuses were diagnosed with atrial flutter (AFL). Thirteen fetuses had persistent AFL and three fetuses had intermittent AFL. Seven patients had hydrops, of which one had Ebstein's anomaly and the other six had normal hearts. Three of the fetuses that presented with AFL were diagnosed at 20, 21, and 23 weeks' gestation and the remainder were diagnosed in the third trimester. Thirteen patients with AFL received antiarrhythmic drugs and three were delivered without any treatment. Five fetuses with AFL developed atrioventricular reciprocating tachycardia following DC cardioversion after birth, and four of them exhibited pre-excitation on the ECG. These five patients (31.3%) required postnatal antiarrhythmic treatment for up to 2 years. Pre-excitation disappeared in two patients during follow-up and two asymptomatic patients with neonatal pre-excitation required accessory pathway ablation. Fetal atrial flutter has a strong association with atrioventricular reciprocating tachycardia and ventricular pre-excitation in the neonatal period. Therefore, electrocardiograms should be carefully reviewed in newborns following the initial resolution of atrial flutter.

Antenatal Therapy for Fetal Supraventricular Tachyarrhythmias: Multicenter Trial

BACKGROUND

Standardized treatment of fetal tachyarrhythmia has not been established.

OBJECTIVES

This study sought to evaluate the safety and efficacy of protocol-defined transplacental treatment for fetal supraventricular tachycardia (SVT) and atrial flutter (AFL).

METHODS

In this multicenter, single-arm trial, protocol-defined transplacental treatment using digoxin, sotalol, and flecainide was performed for singleton pregnancies from 22 to <37 weeks of gestation with sustained fetal SVT or AFL ≥180 beats/min. The primary endpoint was resolution of fetal tachyarrhythmia. Secondary endpoints were fetal death, pre-term birth, and neonatal arrhythmia. Adverse events (AEs) were also assessed.

RESULTS

A total of 50 patients were enrolled at 15 institutions in Japan from 2010 to 2017; short ventriculoatrial (VA) SVT (n = 17), long VA SVT (n = 4), and AFL (n = 29). One patient with AFL was excluded because of withdrawal of consent. Fetal tachyarrhythmia resolved in 89.8% (44 of 49) of cases overall and in 75.0% (3 of 4) of cases of fetal hydrops. Pre-term births occurred in 20.4% (10 of 49) of patients. Maternal AEs were observed in 78.0% (39 of 50) of patients. Serious AEs occurred in 1 mother and 4 fetuses, thus resulting in discontinuation of protocol treatment in 4 patients. Two fetal deaths occurred, mainly caused by heart failure. Neonatal tachyarrhythmia was observed in 31.9% (15 of 47) of neonates within 2 weeks after birth.

CONCLUSIONS

Protocol-defined transplacental treatment for fetal SVT and AFL was effective and tolerable in 90% of patients. However, it should be kept in mind that serious AEs may take place in fetuses and that tachyarrhythmias may recur within the first 2 weeks after birth.

Low mortality in fetal supraventricular tachycardia: Outcomes in a 30-year single-institution experience

OBJECTIVES

To describe a single institutional experience managing fetuses with supraventricular tachycardia (SVT) and to identify associations between patient characteristics and fetal and postnatal outcomes.

BACKGROUND

Sustained fetal SVT is associated with significant morbidity and mortality if untreated, yet the optimal management strategy remains unclear.

METHODS

Retrospective cohort study including fetuses diagnosed with sustained SVT (>50% of the diagnostic echocardiogram) between 1985 and 2018. Fetuses with congenital heart disease were excluded.

RESULTS

Sustained SVT was diagnosed in 65 fetuses at a median gestational age of 30 weeks (range, 14-37). Atrioventricular re-entrant tachycardia and atrial flutter were the most common diagnoses, seen in 41 and 16 cases, respectively. Moderate/severe ventricular dysfunction was present in 20 fetuses, and hydrops fetalis was present in 13. Of the 57 fetuses initiated on transplacental drug therapy, 47 received digoxin first-line, yet 39 of 57 (68%) required advanced therapy with sotalol, flecainide, or amiodarone. Rate or rhythm control was achieved in 47 of 57 treated fetuses. There were no cases of intrauterine fetal demise. Later gestational age at fetal diagnosis (odds ratio [OR], 1.1, 95% confidence interval [CI], 1.01-1.2, P = .02) and moderate/severe fetal ventricular dysfunction (OR, 6.1, 95% CI, 1.7-21.6, P = .005) were associated with postnatal SVT. Two postnatal deaths occurred.

CONCLUSIONS

Fetuses with structurally normal hearts and sustained SVT can be effectively managed with transplacental drug therapy with minimal risk of intrauterine fetal demise. Treatment requires multiple antiarrhythmic agents in over half of cases. Later gestational age at fetal diagnosis and the presence of depressed fetal ventricular function, but not hydrops, predict postnatal arrhythmia burden.

Extended multi-drug maternal therapy for refractory supraventricular tachycardia in premature hydrops fetalis

Background

Fetal supraventricular tachycardia (SVT) is a reversible cause of fetal hydrops, with better outcomes if detected early and reverted in utero. Modern imaging allows accurate diagnosis and maternal anti-arrhythmic therapy can be practiced ensuring in utero cardioversion.

Case presentation

We present a case of preterm fetal hydrops due to SVT successfully reverted in utero by multidrug maternal therapy. The mother presented to our tertiary care hospital at 32 weeks’ gestation with a fetal heart rate of 229 beats/min with evidence of mild fetal pericardial effusion and ascites. Under strict maternal monitoring, the treatment was started with parenteral digoxin. Flecainide, sotalol and amiodarone were introduced sequentially based on the response until cardioversion was achieved at 35 weeks with no maternal side effects. She labored spontaneously and delivered a 2.6 kg baby boy 4 days after the successful cardioversion. The baby was discharged home on day 7 on oral amiodarone with outpatient follow-up. Digoxin monotherapy failed in our case, possibly due to evidence of hydrops and a sequential multi-drug therapy was required for an extended duration of up to 2 weeks to achieve cardioversion successfully.

Conclusions

Our report suggests that multi-drug therapy is more successful in cases of SVT with fetal hydrops, titrated according to fetal response and maternal tolerance, although a prolonged period of therapy might be required to achieve the desired clinical effect.

Prenatal therapy for fetal cardiac disorders

Fetal cardiac abnormalities are some of the commonest congenital disorders seen in prenatal life. They can be anatomical or functional and can develop de novo or as a consequence of either maternal or fetal disease. Untreated, morbidity and mortality rates are high for hypoplastic left heart disorders and for some fetal tachy and bradyarrhythmias. Optimum management strategies are often not clear because of the lack of knowledge about the precise natural history of some of these conditions. Prenatal therapy ranges from invasive fetal cardiac intervention to maternal administration of drugs for transplacental transfer to the fetus. This comprehensive review covers many fetal cardiac disorders and various prenatal therapeutic options that are available.

Clinical presentation, management, and postnatal outcomes of fetal tachyarrhythmias: A 10-year single-center experience

Background

Limited information is available regarding the prevalence and outcomes of fetal tachyarrhythmias from the developing countries.

Aims

This study aims to report referral patterns, management protocols, and pregnancy outcomes of fetuses with tachyarrhythmias reporting to a single center in South India.

Methods

All fetuses with documented sustained fetal tachyarrhythmia during the study period (2008-2017) were included. Arrhythmia characterization and hemodynamic evaluation were done using fetal echocardiography. Patients were grouped into supraventricular tachycardia (SVT) and atrial flutter (AF) groups. Patient characteristics, transplacental therapy (TPT), pregnancy, and postnatal outcomes were analyzed.

Results

Total of 19 fetuses included; 11 had SVT and 8 AF. Mean gestational age at referral was higher for AF (32.5 ± 3.2 vs. 29.6 ± 3.3 weeks; P = 0.05). Hydrops fetalis was present 8 (42%) fetuses; 4 in each group. TPT was instituted in 18 fetuses; 12 (66.7%) received combination therapy; 4 (21%) received direct fetal therapy. Eighteen fetuses (91%) were born alive with one intrauterine death in a fetus with SVT and severe hydrops. Seven (87.5%) fetuses with hydrops survived. Twelve patients (66.7%) were delivered in sinus rhythm. Six babies (33.3%) had tachycardia at birth requiring anti-arrhythmic therapy. All patients survived the neonatal period. Duration of trans-placental therapy (3.8 + 3.3 vs. 7.3 + 3.4 weeks) was shorter in the AF group.

Conclusions

Aggressive TPT using combination of drugs achieves excellent pregnancy and postnatal outcomes in fetuses with tachyarrhythmia. Early diagnosis and prompt referral before hemodynamic decompensation is critical for ensuring optimal outcomes.

First-Line Antiarrhythmic Transplacental Treatment for Fetal Tachyarrhythmia: A Systematic Review and Meta-Analysis

Background

There is no consensus on the most effective and best tolerated first‐line antiarrhythmic treatment for fetal tachyarrhythmia. The purpose of this systematic review and meta‐analysis was to compare the efficacy, safety, and fetal–maternal tolerance of first‐line monotherapies for fetal supraventricular tachycardia and atrial flutter.

Methods and Results

A comprehensive search of several databases was conducted through January 2017. Only studies that made a direct comparison between first‐line treatments of fetal tachyarrhythmia were included. Outcomes of interest were termination of fetal tachyarrhythmia, fetal demise, and maternal complications. Ten studies met inclusion criteria, with 537 patients. Overall, 291 patients were treated with digoxin, 137 with flecainide, 102 with sotalol, and 7 with amiodarone. Digoxin achieved a lower rate of supraventricular tachycardia termination compared with flecainide (odds ratio [OR]: 0.773; 95% confidence interval [CI], 0.605–0.987; I²=34%). In fetuses with hydrops fetalis, digoxin had lower rates of tachycardia termination compared with flecainide (OR: 0.412; 95% CI, 0.268–0.632; I²=0%). There was no significant difference in the incidence of maternal side effects between digoxin and flecainide groups (OR: 1.134; 95% CI, 0.129–9.935; I²=80.79%). The incidence of maternal side effects was higher in patients treated with digoxin compared with sotalol (OR: 3.148; 95% CI, 1.468–6.751; I²=0%). There was no difference in fetal demise between flecainide and digoxin (OR: 0.767; 95% CI, 0.140–4.197; I²=44%).

Conclusions

Flecainide may be more effective treatment than digoxin as a first‐line treatment for fetal supraventricular tachycardia.

Importance of Fetal Arrhythmias to the Neonatologist and Pediatrician

Sudden, unexplained death during the perinatal period remains a major, longstanding challenge. Recent advances in diagnostic techniques and genetic testing has provided evidence that a significant fraction of these deaths may result from lethal cardiac arrhythmias. In this paper, we review current methods of diagnosing arrhythmia in the fetus and strategies for management of life-threatening arrhythmia throughout the perinatal period, including transitional care at the time of delivery.

Fetal Atrial Flutter: Electrophysiology and Associations With Rhythms Involving an Accessory Pathway

BACKGROUND

Atrial flutter (AFl) accounts for up to one third of all fetal tachyarrhythmias and can result in premature delivery, hydrops, and fetal death in 10% of cases; however, the electrophysiology of AFl in utero is virtually unstudied.

METHODS AND RESULTS

In this observational study, we reviewed 19 fetal magnetocardiography studies from 16 fetuses: 15 fetuses (21-38 weeks' gestation) referred with an echocardiographic diagnosis of AFl and 1 fetus (20 weeks' gestation) referred with a diagnosis of tachycardia that was shown by fetal magnetocardiography to have transient AFl in addition to atrioventricular reciprocating tachycardia. Thirteen fetuses showed AFl during the fetal magnetocardiography session, including 4 that presented prior to the third trimester. Five fetuses had incessant AFl; all but 1 of the others with AFl showed additional significant rhythms. Specifically, AFl showed a strong association with rhythms involving an accessory pathway: atrioventricular reciprocating tachycardia, blocked reentrant premature atrial contractions, and ventricular preexcitation. The observed initiations and terminations of AFl most often involved reentrant premature atrial contractions. Spontaneous termination of AFl showed AFl cycle length oscillations. Nine fetuses with 2:1 AFl also showed periods of 4:1 conduction or variable conduction that oscillated between 2:1 and 4:1; however, 3:1 AFl was relatively rare.

CONCLUSIONS

Fetal AFl can occur as early as midgestation and is often accompanied by atrioventricular reciprocating tachycardia and other rhythms associated with an accessory pathway. The findings depict critical differences in the electrophysiology of AFl in the fetus versus the neonate.

Pharmacological Therapy of Tachyarrhythmias During Pregnancy

Tachyarrhythmias are the most frequently observed cardiac complications during pregnancy. The majority of these maternal and foetal arrhythmias are supraventricular tachyarrhythmias; ventricular tachyarrhythmias are rare. The use of anti-arrhythmic drugs (AADs) during pregnancy is challenging due to potential foetal teratogenic effects. Maintaining stable and effective therapeutic maternal drug levels is difficult due to haemodynamic and metabolic alterations. Pharmacological treatment of tachyarrhythmias is indicated in case of maternal haemodynamic instability or hydrops fetalis. Evidenc e regarding the efficacy and safety of AAD therapy during pregnancy is scarce and the choice of AAD should be based on individual risk assessments for both mother and foetus. This review outlines the current knowledge on the development of tachyarrhythmias during pregnancy, the indications for and considerations of pharmacological treatment and its potential side-effects.

Foetal tachyarrhythmia treatment remains challenging even if the vast majority of cases have a favourable outcome

AIM

The optimal treatment for foetal tachyarrhythmia remains controversial, and this study aimed to fill this gap in the knowledge.

METHODS

We retrospectively reviewed all cases of foetal tachyarrhythmia diagnosed at two tertiary foetal cardiology centres in Sweden from 1990 to 2012.

RESULTS

Of the 153 cases, 28% had atrial flutter (AF), 63% had atrioventricular reentrant tachycardia (AVRT) and 9% had other mechanisms. Hydrops was present in 45, less frequently in AF than in AVRT. Transplacental treatment was commenced in 99 and the rhythm normalised in two-thirds, without any significant difference in cardioversion rates between AF and AVRT cases or nonhydropic and hydropic foetuses. Sotalol treatment had a higher cardioversion rate than digoxin in AVRT (63% versus 33%, p < 0.05) but not in AF (57% versus 56%). Two or more drugs were used in 38%. Neonatal survival was 100% in nonhydropic and 84% in hydropic cases. After a median of eight years, 11/134 patients still had arrhythmias, one had died due to arrhythmia and another had undergone cardiac transplantation.

CONCLUSION

Transplacental treatment was frequently insufficient to obtain cardioversion in nonhydropic and hydropic foetuses, but all nonhydropic cases had favourable outcomes. Larger prospective studies are needed to optimise the treatment of cases with hydrops.

Tachycardia in the Neonate

Atrial flutter (AFL) is the second most common type of tachyarrhythmia in the fetus and neonate. An atrial rate of 240 to 360 beats per minute, 2:1 atrioventricular conduction, and a "saw tooth" appearance on electrocardiogram (ECG) are characteristic. On echocardiogram, bilateral atrial dilatation is the most common finding. Treatment is dependent on the severity of symptoms; delivery is usually indicated in the case of fetal heart failure or hydrops fetalis, whereas postnatal AFL is most commonly treated with direct current cardioversion (DCC). This article presents an illustrative case in which the patient presented antenatally via abnormal nonstress testing and subsequent fetal echocardiogram that was concerning for AFL. Postnatal ECG confirmed this diagnosis and the patient received DCC on the day of birth, followed by digoxin and propranolol as maintenance therapy.

A case series of neonatal arrhythmias

OBJECTIVE

Neonatal arrhythmias (NAs) are defined as abnormal heart rates in the neonatal period. They may occur as a result of various cardiovascular, systemic and metabolic problems.

METHODS

A retrospective chart review was performed on newborns who were diagnosed with NA during hospitalization in a neonatal intensive care unit (NICU), or who were admitted to the NICU because of an arrhythmia diagnosis in two NICUs in Turkey from May 2011 to June 2013.

RESULTS

Seventeen neonates with arrhythmias were identified. The incidence of NA was 0.4% and 0.3% in the two NICUs, and was 0.37% in the study population as a whole. Mean gestational age was 37 (29-40) weeks. Nine of the infants (53%) were diagnosed with fetal arrhythmia (FA) during the last week of gestation. The distribution of NA types was as follows: six (35%) supraventricular tachycardia (SVT), six (35%) premature atrial contractions (PACs), two (11%) premature ventricular contractions (PVCs), two (11%) multiple arrhythmias such as SVT + PAC and AV block + PVC, and one (5%) AV block. Wolff-Parkinson-White syndrome was present in one patient. An association of NA with congenital heart malformations was identified in five cases.

CONCLUSIONS

Cardiac arrhythmias are important causes of infant morbidity, and an occasional cause of infant mortality if undiagnosed and untreated. It is important for the physician to be aware of the etiology, development and natural history of arrhythmias in the fetal and neonatal period.

Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association

BACKGROUND

The goal of this statement is to review available literature and to put forth a scientific statement on the current practice of fetal cardiac medicine, including the diagnosis and management of fetal cardiovascular disease.

METHODS AND RESULTS

A writing group appointed by the American Heart Association reviewed the available literature pertaining to topics relevant to fetal cardiac medicine, including the diagnosis of congenital heart disease and arrhythmias, assessment of cardiac function and the cardiovascular system, and available treatment options. The American College of Cardiology/American Heart Association classification of recommendations and level of evidence for practice guidelines were applied to the current practice of fetal cardiac medicine. Recommendations relating to the specifics of fetal diagnosis, including the timing of referral for study, indications for referral, and experience suggested for performance and interpretation of studies, are presented. The components of a fetal echocardiogram are described in detail, including descriptions of the assessment of cardiac anatomy, cardiac function, and rhythm. Complementary modalities for fetal cardiac assessment are reviewed, including the use of advanced ultrasound techniques, fetal magnetic resonance imaging, and fetal magnetocardiography and electrocardiography for rhythm assessment. Models for parental counseling and a discussion of parental stress and depression assessments are reviewed. Available fetal therapies, including medical management for arrhythmias or heart failure and closed or open intervention for diseases affecting the cardiovascular system such as twin-twin transfusion syndrome, lung masses, and vascular tumors, are highlighted. Catheter-based intervention strategies to prevent the progression of disease in utero are also discussed. Recommendations for delivery planning strategies for fetuses with congenital heart disease including models based on classification of disease severity and delivery room treatment will be highlighted. Outcome assessment is reviewed to show the benefit of prenatal diagnosis and management as they affect outcome for babies with congenital heart disease.

CONCLUSIONS

Fetal cardiac medicine has evolved considerably over the past 2 decades, predominantly in response to advances in imaging technology and innovations in therapies. The diagnosis of cardiac disease in the fetus is mostly made with ultrasound; however, new technologies, including 3- and 4-dimensional echocardiography, magnetic resonance imaging, and fetal electrocardiography and magnetocardiography, are available. Medical and interventional treatments for select diseases and strategies for delivery room care enable stabilization of high-risk fetuses and contribute to improved outcomes. This statement highlights what is currently known and recommended on the basis of evidence and experience in the rapidly advancing and highly specialized field of fetal cardiac care.

Sotalol as first-line treatment for fetal tachycardia and neonatal follow-up

OBJECTIVES

In fetal tachycardia, pharmacological therapy with digoxin, flecainide and sotalol has been reported to be effective. In a recent retrospective multicenter study, sotalol was considered to be less effective than the other drugs in treatment of fetal supraventricular tachycardia (SVT). The aim of this study was to re-evaluate the efficacy and safety of maternally administered sotalol in the treatment of fetal tachycardia.

METHODS

This was a retrospective review of the records of 30 consecutive fetuses with tachycardia documented on M-mode echocardiography between January 2004 and December 2010 at Wilhelmina Children's Hospital, a tertiary referral university hospital. Patients were subdivided into those diagnosed with supraventricular tachycardia and those with atrial flutter (AF) and presence of hydrops was noted. Other variables investigated included QTc interval measured on maternal electrocardiogram before and after initiation of antiarrhythmic therapy, fetal heart rhythm and heart rate pre- and postnatally, oral maternal drug therapy used, time to conversion to sinus rhythm (SR), percentage of fetuses converted following transplacental treatment, maternal adverse effects, presence or absence of tachycardia as noted on postnatal ECG, postnatal therapy or prophylaxis and neonatal outcome. Findings are discussed with reference to the literature.

RESULTS

A total of 28 patients (18 with SVT, 10 with AF) were treated with sotalol as first-line therapy. Fetal hydrops was present in six patients (five with SVT, one with AF). All hydropic patients converted antenatally to SR (67% with sotalol as a single-drug therapy, 33% after addition of flecainide). Of the non-hydropic patients, 91% converted to SR (90% with sotalol only, 10% after addition of flecainide or digoxin). In 9% (with AF) rate control was achieved. There was no mortality. No serious drug-related adverse events were observed. Postnatally, rhythm disturbances were detected in 10 patients, two of whom still had AF. In eight, SVT was observed within 3 weeks postnatally, and in five of these within 72 hours.

CONCLUSIONS

Sotalol can be recommended as the drug of first choice for treatment of fetal AF and has been shown to be an effective and safe first-line treatment option for SVT, at least in the absence of hydrops. Postnatal maintenance therapy after successful prenatal therapy is not necessarily indicated, as the risk of recurrence is low beyond 72 hours of age.

Fetal diagnosis and imaging in cardiology

BACKGROUND

Fetal echocardiography plays a critical role in the diagnosis and management of structural, functional and rhythm-related fetal cardiovascular disease.

OBJECTIVES/METHODS

This article reviews the history of fetal echocardiography and the prenatal diagnosis of fetal cardiovascular disease as well as the evolution of the field of fetal cardiology. The clinical application of fetal echocardiography, including indications for referral, timing of referral and considerations in the diagnosis and serial assessment of fetal cardiovascular disease, is presented.

CONCLUSIONS

Newer directions in the field of fetal cardiology, including first trimester diagnoses and fetal intervention, will continue to expand its role in the evaluation and treatment of affected pregnancies in the future; however, equally as important are efforts to continue to improve prenatal detection rates.

Postnatal outcome in patients with fetal tachycardia

The diagnosis and management of prenatal tachyarrhythmias is well established; however, the postnatal course and outcomes are not. The purpose of our study was to review the natural history of patients with fetal tachycardia, determine the incidence of postnatal arrhythmias, and determine whether there are factors to predict which fetuses will develop postnatal arrhythmias. A retrospective chart review of patients with fetal tachyarrhythmias investigated at British Columbia Children's and Women's Hospitals between 1983 and 2010 was conducted. Sixty-nine mother-fetus pairs were eligible for the study. Fifty-two had fetal supraventricular tachycardia, and 17 had fetal atrial flutter. Conversion to sinus rhythm occurred prenatally in 52 % of patients. Postnatal arrhythmia occurred in two thirds of patients, with 82 % of those cases occurring within the first 48 h of life. Hydrops fetalis, female sex, and lack of conversion to sinus rhythm was predictive of postnatal arrhythmia (P = 0.01, P = 0.01, and P = 0.001, respectively). Conversion to sinus rhythm prenatally did not predict postnatal arrhythmia. Median duration of treatment was 9 months. Two postnatal deaths of unknown etiology occurred. Two thirds of all patients with prenatal tachycardia will develop postnatal arrhythmia. Prenatal factors that predict postnatal arrhythmia include hydrops, sex, and whether or not conversion to sinus rhythm occurred prenatally. The majority of patients with postnatal arrhythmia present within 48 h of life, which has clinical implications for monitoring. Postnatal outcome is generally very good with most patients being weaned off medication in 6-12 months.

Single-catheter radiofrequency ablation of a permanent junctional reciprocating tachycardia in a premature neonate

A 34-week premature neonate presented with drug-refractory permanent junctional incessant tachycardia and haemodynamic compromise. The patient underwent successful radiofrequency catheter ablation using a single-catheter approach. The child remains in sinus rhythm, without pharmacological treatment, 2 years after the procedure.

Rapid control of foetal supraventricular tachycardia with digoxin and flecainide combination treatment

OBJECTIVES

To evaluate the efficacy of flecainide and digoxin combination in foetal supraventricular tachycardia.

SETTING

This study was carried out in a tertiary referral centre.

METHODS

We conducted a retrospective review of 29 patients diagnosed with supraventricular foetal tachycardia between 2001 and 2009. Mode of presentation, foetal cardiac function, maternal anti-arrhythmic serum levels, drug tolerance, and maternal electrocardiogram recordings were assessed. The postnatal outcome of each infant was also evaluated for tachycardia recurrence.

RESULTS

In all, 27 foetuses were treated with digoxin and flecainide combination, and two foetuses were delivered without any treatment. Of the 27 foetuses treated, six [corrected] had atrial flutter and the remaining 21 [corrected] had atrioventricular re-entry tachycardia. There were eight foetuses with hydrops (27%), of whom three had atrial flutter and five had atrioventricular re-entry tachycardia; 26 foetuses (96%) responded to flecainide and digoxin combination, with restoration of sinus rhythm in 22 (81.4%) and rate control in the other four. In one severely hydropic foetus, there was no response to treatment. In all, 26 treated infants were delivered alive, but one pregnancy was terminated for non-cardiac causes when the foetus was in sinus rhythm. There was no intrauterine death due to tachycardia. Although there were minor side effects to anti-arrhythmic medications, none of the pregnant women developed proarrhythmia.

CONCLUSION

Flecainide and digoxin combination treatment offers a safe and effective treatment for foetal supraventricular tachycardia with fast restoration of sinus rhythm.

Effectiveness of sotalol as first-line therapy for fetal supraventricular tachyarrhythmias

Fetal supraventricular tachycardia (SVT) and atrial flutter (AF) can be associated with significant morbidity and mortality. Digoxin is often used as first-line therapy but can be ineffective and is poorly transferred to the fetus in the presence of fetal hydrops. As an alternative to digoxin monotherapy, we have been using sotalol at presentation in fetuses with SVT or AF with, or at risk of, developing hydrops to attempt to achieve more rapid control of the arrhythmia. The present study was a retrospective review of the clinical, echocardiographic, and electrocardiographic data from all pregnancies with fetal tachycardia diagnosed and managed at a single center from 2004 to 2008. Of 29 affected pregnancies, 21 (16 SVT and 5 AF) were treated with sotalol at presentation, with or without concurrent administration of digoxin. Of the 21, 11 (6 SVT and 5 AF) had resolution of the tachycardia within 5 days (median 1). Six others showed some response (less frequent tachycardia, rate slowing, resolution of hydrops) without complete conversion. In 1 fetus with a slow response, the mother chose pregnancy termination. The 5 survivors with a slow response were all difficult to treat postnatally, including 1 requiring radiofrequency ablation as a neonate. One fetus developed blocked atrial extrasystoles after 1 dose of sotalol and was prematurely delivered for fetal bradycardia. Three grossly hydropic fetuses with SVT showed no response and died within 1 to 3 days of treatment. In conclusion, transplacental sotalol, alone or combined with digoxin, is effective for the treatment of fetal SVT and AF, with an 85% complete or partial response rate in our series.

Impact of fetal echocardiography

Prenatal diagnosis of congenital heart disease is now well established for a wide range of cardiac anomalies. Diagnosis of congenital heart disease during fetal life not only identifies the cardiac lesion but may also lead to detection of associated abnormalities. This information allows a detailed discussion of the prognosis with parents. For continuing pregnancies, appropriate preparation can be made to optimize the postnatal outcome. Reduced morbidity and mortality, following antenatal diagnosis, has been reported for coarctation of the aorta, hypoplastic left heart syndrome, and transposition of the great arteries. With regard to screening policy, most affected fetuses are in the “low risk” population, emphasizing the importance of appropriate training for those who undertake such obstetric anomaly scans. As a minimum, the four chamber view of the fetal heart should be incorporated into midtrimester anomaly scans, and where feasible, views of the outflow tracts should also be included, to increase the diagnostic yield. Newer screening techniques, such as measurement of nuchal translucency, may contribute to identification of fetuses at high risk for congenital heart disease and prompt referral for detailed cardiac assessment.

Perinatal management and long-term cardiac outcome in fetal arrhythmia

BACKGROUND

cardiac arrhythmias are commonly observed in the fetus, however, may have major consequences for fetal development and post natal life.

AIMS

to evaluate the perinatal management and cardiac outcome of fetuses with tachy- or bradyarrhythmia.

STUDY DESIGN

perinatal management, outcome and long-term cardiac follow-up were evaluated retrospectively in consecutive fetuses with cardiac arrhythmias.

RESULTS

forty-four fetuses were diagnosed: supraventricular tachycardia (SVT, n=28), atrial flutter (AF, n=7) and atrioventricular block (AVB, n=9). The overall incidence of cardiac anomalies was 18% mainly in the AVB group; hydrops was present in 34%. Direct or transplacental fetal anti-arrhythmic medication was given in 76%. Mortality was 6% in SVT/AF and 78% in the AVB group, respectively. AF resolved in all patients. In the SVT group, Wolff-Parkinson-White (WPW) syndrome was present in 21%, diagnosed at birth or later in life. After the age of one year about 90% of patients in the SVT group remained asymptomatic and free of drugs (median follow-up 76months).

CONCLUSIONS

mortality rate is low in patients with fetal SVT and AF but high in patients with AVB. Related morbidity includes WPW-syndrome and congenital cardiac anomalies. Electrocardiographic screening is recommended in all fetal SVT cases before adolescence since WPW-syndrome may occur later in life.

Fetal ventricular tachycardia secondary to long QT syndrome treated with maternal intravenous magnesium: case report and review of the literature

Ventricular tachycardia is a very rare fetal arrhythmia accounting for fewer than 2% of fetal tachycardias. We describe a fetus presenting at 30 weeks' gestation with ventricular tachycardia at a rate of 220 beats per min and fetal hydrops. The tachycardia was unresponsive to flecainide but was controlled within 12 h by an intravenous infusion of magnesium to the mother. Despite rapid control of the arrhythmia the fetus developed severe periventricular leukomalacia before birth for which a poor neurological prognosis was given. The baby was delivered preterm at 32 weeks' gestation and died on the sixth day after birth. Long QT syndrome was identified postnatally on the electrocardiogram, and was confirmed by genetic testing which showed a mutation in the KCNH2 gene (p.T613M).

Diagnosis, clinical features, management, and post-natal follow-up of fetal tachycardias

OBJECTIVE

To evaluate the diagnosis, clinical features, management and post-natal follow-up in consecutive fetuses identified with tachycardia.

METHODS

We reviewed consecutive fetuses with tachycardia identified in a single tertiary institution between January, 2001, and December, 2008. We considered several options for management, including no treatment but close surveillance, trans-placental antiarrhythmic therapy in fetuses presenting prior to 36 weeks of gestation, and delivery and treatment as a neonate for fetuses presenting after 36 weeks of gestation. Data was gathered by a review of prenatal and postnatal documentation.

RESULTS

Among 29 fetuses with tachycardia, 21 had supraventricular tachycardia with 1 to 1 conduction, 4 had atrial flutter, 3 had atrial tachycardia, while the remaining fetus had ventricular tachycardia. Of the group, 8 fetuses (27.6%) were hydropic. Transplacental administration of antiarrhythmic drugs was used in just over half the fetuses, delivery and treatment as a neonate in one-quarter, and no intervention but close surveillance in one-sixth of the case. Twenty-six of 29 fetuses (89.7%) were born alive. Only patients with fetal hydrops suffered mortality, with 37.5% of this group dying, this being statistically significant, with the value of p equal to 0.03, when compared to non-hydropic fetuses. Only 3 patients (11.5%) were receiving antiarrhythmic prophylaxis beyond the first year of life.

CONCLUSION

A significant proportion of fetal tachycardias recognized before 36 weeks of gestation can be treated successfully by transplacental administration of antiarrhythmic drugs. Fetuses presenting after 36 weeks of gestation can be effectively managed postnatally. The long-term prognosis for fetuses diagnosed with tachycardia is excellent, with the abnormal rhythm resolving spontaneously during the first year of life in most of them.

Long-term neurodevelopmental outcome after fetal arrhythmia

OBJECTIVE

The purpose of this study was to determine the long-term neurodevelopmental outcome in fetuses with severe tachy- or bradyarrhythmia.

STUDY DESIGN

This was a follow-up study to assess the neurologic, mental, and psychomotor development in cases with fetal cardiac arrhythmia.

RESULTS

A total of 44 fetuses were diagnosed with fetal tachy- or bradyarrhythmia: 28 fetuses had supraventricular tachycardia (SVT); 7 fetuses had atrial flutter (AF), and 9 fetuses had atrioventricular block (AVB). The mortality rate was low (6%; 2/35 fetuses) in the SVT and AF groups and high in the AVB group (78%; 7/9 fetuses). Six patients were lost to follow-up evaluation (14%). Neurodevelopmental outcome was normal in all survivors in the SVT and AF groups, except for 1 patient who experienced plexus brachialis injury because of shoulder dystocia. Two of the 3 survivors in the AVB group had severe developmental delay.

CONCLUSION

The mortality rate and neurodevelopmental impairment in infants with SVT and AF are low, but the mortality rate in infants with AVB is elevated.