Successful in utero transesophageal pacing for severe drug-resistant tachyarrhythmia

Outcomes of sustained fetal tachyarrhythmias after transplacental treatment

Background

Fetal tachyarrhythmia is a condition that may lead to cardiac dysfunction, hydrops, and death. Despite a transplacental treatment, failure to obtain or maintain sinus rhythm may occur.

Objective

We aimed to analyze the perinatal outcomes of sustained fetal tachyarrhythmias after in utero treatment.

Methods

We performed a retrospective evaluation of 69 cases with sustained fetal tachyarrhythmia. We compared the perinatal and long-term outcomes of prenatally converted and drug-resistant fetuses. Tachyarrhythmia subtypes were also evaluated.

Results

Conversion to sinus rhythm was obtained in 74% of cases; 26% of cases were drug-resistant and delivered arrhythmic. Three perinatal deaths occurred in both groups (6.7% vs 17%, P = .34). Neonates delivered arrhythmic were more frequently admitted to neonatal intensive care units (75% vs 31%, P < .01), and their hospital stay was longer (20.9 vs 6.64 days, P < .001). Multiple neonatal recurrences (81% vs 11%, P < .001), temporary hemodynamic dysfunction or heart failure (50% vs 6.7%, P < .001), and postnatal use of a combination treatment (44% vs 13%, P = .028) were also more frequent in this population. Beyond the neonatal period, rates of recurrences within the first 16 months were higher in drug-resistant fetuses (HR = 16.14, CI 95% [4.485; 193.8], P < .001). In this population, postnatal electrocardiogram revealed an overrepresentation of rare mechanisms, especially permanent junctional reciprocating tachycardia (PJRT) (31%).

Conclusion

Prenatal conversion to stable sinus rhythm is a major determinant of perinatal and long-term outcomes in fetal tachyarrhythmias. The underlying electrophysiological mechanisms have a major role in predicting these differential outcomes with an overrepresentation of PJRT in the drug-resistant population.

Prenatal diagnosis of laryngo-tracheo-esophageal anomalies in fetuses with congenital diaphragmatic hernia by ultrasound evaluation of the vocal cords and fetal laryngoesophagoscopy

BACKGROUND

To evaluate the incidence of laryngeal ultrasound (US) abnormalities in fetuses with congenital diaphragmatic hernia (CDH) and to assess the utility of fetal laryngoesophagoscopy for prenatal diagnosis of laryngo-tracheo-esophageal anomalies.

STUDY DESIGN

A cohort of CDH fetuses with laryngeal ultrasound abnormalities were selected for diagnostic fetal laringoesophagoscopy in a single fetal surgery center at Queretaro, Mexico.

RESULTS

During the study period, 210 CDH fetuses were evaluated. US examination of the vocal cords was successfully performed in all fetuses, and abnormal ultrasound findings were observed in four cases (1.9%). Fetal laringoesophagoscopy was successfully performed in all four cases at a median gestational age of 29.5 (range, 28.1-30.6) weeks. During fetal intervention, a laryngo-tracheo-esophageal cleft (TEC) extending from the larynx to the carina (type IV) was endoscopically visualized in three cases, and laryngeal atresia coexisting with TEC was confirmed in the remaining case. Fetal karyotype was normal in all cases, but abnormal chromosomal microarray analysis was reported in two cases (50%). All cases were delivered liveborn with severe respiratory failure presenting cardiac arrest and immediate neonatal death.

CONCLUSIONS

Laryngeal anomalies in CDH fetuses can be presumed by ultrasound evaluation of the vocal cords and confirmed by fetal laryngoesophagoscopy during pregnancy.

Fetal arrhythmias: prenatal evaluation and intrauterine therapeutics

Introduction

Fetal arrhythmias are a common phenomenon with rather complicated etiologies. Debates remain regarding prenatal diagnosis and treatment of fetal arrhythmias.

Methods

The literature reporting on prenatal diagnosis and treatment of fetal arrhythmias published in the recent two decades were retrieved, collected and analyzed.

Results

Both fetal magnetocardiogram and electrocardiogram provide information of cardiac time intervals, including the QRS and QT durations. M-mode ultrasound detects the AV and VA intervals, fetal heart rate, and AV conduction. By using Doppler ultrasound, simultaneous recording of the atrial and ventricular waves can be obtained. Benign fetal arrhythmias, including premature contractions and sinus tachycardia, do not need any treatment before and after birth. Sustained fetal arrhythmias that predispose to the occurrence of hydrops fetalis, cardiac dysfunction or eventual fetal demise require active treatments. Intrauterine therapy of fetal tachyarrhythmias has been carried out by the transplacental route. If maternal transplacental treatment fails, intraumbilical, intraperitoneal, or direct fetal intramuscular injection of antiarrhythmic agents can be attempted.

Conclusions

The outcomes of intrauterine therapy of fetal tachyarrhythmias depend on the types or etiology of fetal arrhythmias and fetal conditions. Most are curable to a transplacental treatment by the first-line antiarrhythmic agents. Fetal cardiac pacings are effective methods to restore sinus rhythm in drug-resistant or hemodynamically compromised cases. Immediate postnatal pacemaker implantation is warranted in refractory cases.