Treatment of Fetal Supraventricular Tachycardia

Incidence of Fetal Arrhythmia Before and During the COVID-19 Pandemic: A Single-Center Experience

Fetal arrhythmias are rare and carry significant morbidity and mortality without appropriate treatment. Initial reports exist of fetal arrhythmia in the setting of maternal COVID-19 infection. Our study sought to evaluate incidence of fetal arrhythmia before and during the COVID-19 pandemic at our institution. This retrospective cohort study from a tertiary care fetal cardiac center utilized the institutional REDCap database to search fetal arrhythmia diagnostic codes. Medical records of mother-fetus dyads were reviewed and data were collected on diagnoses, gestational age, treatment regimen, and postnatal outcomes. Patients were divided into pre-COVID and peri-COVID segments. 8368 total pregnancies were evaluated during the 7.3 years of study period. Forty-five patients (0.5%) had a significant fetal arrhythmia and were included in this study: 19 (42%) in the pre-COVID-19 group and 26 (58%) in the peri-COVID-19 group. No patients had associated congenital heart disease. There was a notable increase in the incidence of fetal supraventricular tachycardia (SVT) (1.82 per 1000 vs 2.65 per 1000 pregnancies) and complete heart block (1.04 per 1000 vs 1.77 per 1000 pregnancies) but no apparent change in other tachyarrhythmias during the COVID era. The proportion of antibody-mediated complete heart block increased from 50 to 87.5%. There was also an increase in the percentage of SVT patients requiring postnatal treatment during COVID-19 (53.8% vs 62.5%). Our experience shows an increased incidence of some fetal arrhythmia diagnoses during the COVID-19 pandemic. Additional multi-center studies will be necessary to fully evaluate the increased burden of fetal arrhythmias during the COVID-19 era as well as to elucidate etiology.

Wolff-Parkinson-White Syndrome in the Preterm Neonate

Wolff-Parkinson-White (WPW) syndrome is a rare cardiac condition arising from abnormal embryologic development of the annulus fibrosus in combination with the cardiac conduction system. The abnormality results in the development of accessory pathways and preexcitation changes which can provoke episodes of tachyarrhythmias. The most common presentation of WPW syndrome is supraventricular tachycardia. Beyond customary abortive therapy, chronic management strategies vary based upon timing and clinical severity of the initial disease presentation. Prompt diagnosis and rate control have a dramatic impact on the outcomes of morbidity and mortality. The purpose of this article is to present a case study of a preterm infant who manifested with WPW syndrome. Additionally, the article will explore the pathophysiology of WPW syndrome and the timing and presentation of common clinical manifestations of the disease, along with current diagnostic and treatment strategies to achieve optimal patient outcomes in the neonatal population.

Diagnosis and Management of Fetal Arrhythmias in the Current Era

Diagnosis and management of fetal arrhythmias have changed over the past 40-50 years since propranolol was first used to treat fetal tachycardia in 1975 and when first attempts were made at in utero pacing for complete heart block in 1986. Ongoing clinical trials, including the FAST therapy trial for fetal tachycardia and the STOP-BLOQ trial for anti-Ro-mediated fetal heart block, are working to improve diagnosis and management of fetal arrhythmias for both mother and fetus. We are also learning more about how "silent arrhythmias", like long QT syndrome and other inherited channelopathies, may be identified by recognizing "subtle" abnormalities in fetal heart rate, and while echocardiography yet remains the primary tool for diagnosing fetal arrhythmias, research efforts continue to advance the clinical envelope for fetal electrocardiography and fetal magnetocardiography. Pharmacologic management of fetal arrhythmias remains one of the most successful achievements of fetal intervention. Patience, vigilance, and multidisciplinary collaboration are key to successful diagnosis and treatment.

Diagnosis and treatment of fetal and pediatric age patients (0-12 years) with Wolff-Parkinson-White syndrome and atrioventricular accessory pathways

Overt or concealed accessory pathways are the anatomic substrates of ventricular preexcitation (VP), Wolff-Parkinson-White syndrome (WPW) and paroxysmal supraventricular tachycardia (PSVT). These arrhythmias are commonly observed in pediatric age. PSVT may occur at any age, from fetus to adulthood, and its symptoms range from none to syncope or heart failure. VP too can range from no symptoms to sudden cardiac death. Therefore, these arrhythmias frequently need risk stratification, electrophysiologic study, drug or ablation treatment. In this review of the literature, recommendations are given for diagnosis and treatment of fetal and pediatric age (≤12 years) WPW, VP, PSVT, and criteria for sport participation.

Fetal supraventricular tachycardia and maternal COVID-19 vaccination: is there any relationship?

Fetal supraventricular tachycardia accounts for 60–80% of the fetal tachyarrhythmias with prevalence ranging from 1/1000 to 1/25 000 pregnancies. It may be secondary to fetal anomalies or maternal factors. By reviewing the literature, there is no previous article that reports fetal arrhythmia after maternal vaccination. We present herein two cases of fetal supraventricular tachycardia following the administration of the Pfizer-BioNTech COVID-19 vaccine during pregnancy. Continued safety monitoring and more longitudinal follow-up are needed to evaluate the fetal impact after maternal COVID-19 vaccination.

Management of Fetal Supraventricular Tachycardia: Case Series from a Tertiary Perinatal Cardiac Center

BACKGROUND

Fetal supraventricular tachycardia is a relatively uncommon cardiac rhythm abnormality which is often associated with adverse perinatal outcomes if untreated. Although there are several treatment modalities and protocols in use globally, there is no consensus as to the most effective antiarrhythmic to manage this condition.

AIM

This study aimed to evaluate perinatal outcomes following prenatal maternal therapy for fetal supraventricular tachycardia.

MATERIALS AND METHODS

This was a 20-year retrospective cohort study. Institutional records were reviewed for antenatal therapy choice and maternal and fetal outcomes.

RESULTS

Sixty-nine cases met diagnostic criteria for fetal SVT, of which 56 (81%) received maternal antiarrhythmic therapy. Digoxin was the most common, but least effective, first-line therapy in 28 patients, achieving successful rate reversion in 35.7%. Thirty-one patients (55%) required second-line therapy, and this was most successful with digoxin and flecainide polytherapy achieving rate reversion in 17 of 18 cases (94.5%) at a median of 3 days (1.5-7). Hydrops was present in 23 (33%) cases at initial presentation, 16 of which achieved rate reversion. There was minimal difference in treatment efficacy comparing single- or multiple-agent treatment in the setting of hydrops (50% vs. 42.8%). Side effects occurred in 14/56 treated patients (25%) but were severe in only 8 (14.3%) women, most commonly with digoxin and flecainide polytherapy (6 of 8 cases). There were 3 (4%) fetal deaths amongst the study cohort.

CONCLUSIONS

Digoxin and flecainide polytherapy were well tolerated and successfully achieved rhythm and rate control in fetuses with prenatally diagnosed supraventricular tachycardia. The presence of hydrops was a poor prognostic feature.

Women-specific routes of administration for drugs: A critical overview

The woman's body presents a number of unique anatomical features that can constitute valuable routes for the administration of drugs, either for local or systemic action. These are associated with genitalia (vaginal, endocervical, intrauterine, intrafallopian and intraovarian routes), changes occurring during pregnancy (extra-amniotic, intra-amniotic and intraplacental routes) and the female breast (breast intraductal route). While the vaginal administration of drug products is common, other routes have limited clinical application and are fairly unknown even for scientists involved in drug delivery science. Understanding the possibilities and limitations of women-specific routes is of key importance for the development of new preventative, diagnostic and therapeutic strategies that will ultimately contribute to the advancement of women's health. This article provides an overview on women-specific routes for the administration of drugs, focusing on aspects such as biological features pertaining to drug delivery, relevance in current clinical practice, available drug dosage forms/delivery systems and administration techniques, as well as recent trends in the field.

Nanoparticles in pregnancy: the next frontier in reproductive therapeutics

BACKGROUND

Nanotechnology involves the engineering of structures on a molecular level. Nanomedicine and nano-delivery systems have been designed to deliver therapeutic agents to a target site or organ in a controlled manner, maximizing efficacy while minimizing off-target effects of the therapeutic agent administered. In both reproductive medicine and obstetrics, developing innovative therapeutics is often tempered by fears of damage to the gamete, embryo or developing foetus or of negatively impacting a woman's reproductive potential. Thus, nanomedicine delivery systems may provide alternative targeted intervention strategies, treating the source of the disease and minimizing long-term consequences for the mother and/or her foetus.

OBJECTIVE AND RATIONALE

This review summarizes the current state of nanomedicine technology in reproductive medicine and obstetrics, including safety, potential applications, future directions and the hurdles for translation.

SEARCH METHODS

A comprehensive electronic literature search of PubMed and Web of Science databases was performed to identify studies published in English up until February 2020. Relevant keywords were used to obtain information regarding use of nanoparticle technology in fertility and gene therapy, early pregnancy complications (ectopic pregnancy and gestational trophoblastic disease) and obstetric complications (preeclampsia, foetal growth restriction, preterm birth and gestational diabetes) and for selective treatment of the mother or foetus. Safety of specific nanoparticles to the gamete, embryo and foetus was also investigated.

OUTCOMES

Pre-clinical research in the development of nanoparticle therapeutic delivery is being undertaken in many fields of reproductive medicine. Non-hormonal-targeted nanoparticle therapy for fibroids and endometriosis may provide fertility-sparing medical management. Delivery of interventions via nanotechnology provides opportunities for gene manipulation and delivery in mammalian gametes. Targeting cytotoxic treatments to early pregnancy tissue provides an alternative approach to manage ectopic pregnancies and gestational trophoblastic disease. In pregnancy, nanotherapeutic delivery offers options to stably deliver silencing RNA and microRNA inhibitors to the placenta to regulate gene expression, opening doors to novel genetic treatments for preeclampsia and foetal growth restriction. Restricting delivery of teratogenic drugs to the maternal compartment (such as warfarin) may reduce risks to the foetus. Alternatively, targeted delivery of drugs to the foetus (such as those to treat foetal arrythmias) may minimize side effects for the mother.

WIDER IMPLICATIONS

We expect that further development of targeted therapies using nanoparticles in a reproductive setting has promise to eventually allow safe and directed treatments for conditions impacting the health and reproductive capacity of women and for the management of pregnancy and serious pregnancy complications.

Supraventricular tachycardia in one of the twins: The ethical dilemmas involved in treatment

The pediatric cardiologist now has an important role to play in fetal medicine. They are often called upon to manage fetal cardiac problems such as arrhythmias or perform fetal cardiac interventions such as balloon valvuloplasty or atrial septostomy. In these scenarios, it becomes very important for the pediatric cardiologist to understand the concepts of "fetus as a patient," "viability," etc., and their implications in management. We try to shed light on these principles through our case scenario of managing supraventricular tachycardia in one of the fetuses of a twin pregnancy.