Multiple direct fetal amiodarone administration for supraventricular tachycardia with hydrops fetalis: a case report.

Background: Fetal supraventricular tachycardia (SVT) is the most common fetal tachyarrhythmia and can cause fetal heart failure and intrauterine death. The management varies within institution and usually based on published case series, institutional experience. Case summary: Fetal SVT with hydrops (ascites and subcutaneous edema) was diagnosed at 26 weeks of gestational age. The first direct injection of fetal amiodarone into the umbilical vein resulted in temporary cardioversion to the sinus rhythm and mild transient maternal adverse event. The second direct fetal amiodarone to the fetal peritoneal cavity resulted in conversion to sinus rhythm, resolution of fetal hydrops, and normal fetal growth until delivery at 39 weeks gestational age. Discussion: Treatment of fetal SVT often requires prolonged maternal antiarrhythmic treatment and carries a significant risk of maternal adverse events. Direct fetal antiarrhythmic treatment often requires achieving adequate therapeutic drugs, especially in hydropic fetus. Amiodarone is one of drugs options for fetal SVT with hydrops because it has been shown to be highly effective with low fetal mortality. Continuous vital sign and ECG monitoring should be performed during direct fetal antiarrhythmic administration.

Refractory Fetal Supraventricular Tachycardia with Hydrops Successfully Converted by Intraperitoneal Flecainide in the Fetus: A Case Report.

INTRODUCTION: Supraventricular tachycardia is the most common fetal tachyarrhythmia and if persistent often associated with fetal hydrops which can cause intrauterine and neonatal death. CASE PRESENTATION: We present a case of early second trimester supraventricular tachycardia in a hydropic fetus, initially refractory to transplacental treatment. CONCLUSION: The supraventricular tachycardia was successfully treated when supplemented with intraperitoneal flecainide in the fetus.

Maternal monitoring and safety considerations during antiarrhythmic treatment for fetal supraventricular tachycardia.

Fetal tachycardia is a rare complication during pregnancy. After exclusion of maternal and fetal conditions that can result in a secondary fetal tachycardia, supraventricular tachycardia is the most common cause of a primary sustained fetal tachyarrhythmia. In cases of sustained fetal supraventricular tachycardia, maternal administration of digoxin, flecainide, sotalol, and more rarely amiodarone, is considered. As these medications have the potential to cause significant adverse effects, we sought to examine maternal safety during transplacental treatment of fetal supraventricular tachycardia. In this narrative review we summarize the literature addressing pharmacologic properties, monitoring, and adverse reactions associated with medications most commonly prescribed for transplacental therapy of fetal supraventricular tachycardia. We also describe maternal monitoring practices and adverse events currently reported in the literature. In light of our findings, we provide clinicians with a suggested maternal monitoring protocol aimed at optimizing safety.

Transient neonatal hypothyroidism following a short course of maternal amiodarone therapy.

Background Amiodarone is an iodine-rich medication used to treat maternal and fetal arrhythmias, with known effects on thyroid hormone homeostasis. Case presentation We describe a case of transient neonatal hypothyroidism following a short prenatal course of maternal amiodarone therapy resulting in neonatal TSH elevations exceeding those reported in the available literature.

Morphine-induced supraventricular tachycardia in near-term fetus.

BACKGROUND: Fetal supraventricular tachycardia (SVT), characterized by fetal heart rate between 220 and 260 bpm, is a rare but most commonly encountered fetal cardiac arrhythmia in pregnancy that may be associated with adverse perinatal outcome. CASE PRESENTATION: We describe a 36/6 week near term fetus who presented morphine-induced SVT after maternal treatment of a renal colic. Following emergency cesarean section, the neonate had resolution of symptoms. CONCLUSIONS: The pathophysiology of morphine-related SVT, previously documented in experimental animal models, and for the first time reported in the human fetus, is presented.

Pharmacokinetics and dosing requirements of digoxin in pregnant women treated for fetal supraventricular tachycardia.

BACKGROUND: The objective of this study was to characterize the pharmacokinetics (PK) of digoxin in pregnant women and its potential implications for drug dosing. METHODS: Serum digoxin concentrations (SDCs) obtained in pregnant women treated for fetal supraventricular tachycardia (SVT) was retrospectively collected. PK analysis was comparatively performed using a two-stage approach (PKS™) and a Population PK approach (NONMEM™). As clinical outcome the fetal heart rate was recorded. RESULTS: A total of 42 SDCs were obtained from 8 women in the 3rd trimester of pregnancy (mean age 33.0 years). The PK parameters estimated by both two-stage (volume of distribution (Vd) = 682.0 L, CV = 47.5%; serum clearance (CL) = 16.1 L/h, CV = 19%) and population approaches (Vd = 731.3 L, CV = 30.5%; CL = 18.7 L/h, CV = 17.8%) are very similar and show a clear trend of increasing drug disposition in the third trimester of pregnancy. An oral loading dose of 0.5 mg/8 h during 24 h followed by a maintenance regimen of 0.5 mg/12 h been recommended to start treatment. CONCLUSIONS: Despite the small population, these parameters could be used as a guide to calculate the initial dosage requirements in the third trimester of pregnancy for treating fetal SVT. In addition, maternal SDCs should be routinely monitored for dosage adjustment purposes.

Treatment of Fetal Supraventricular Tachycardia.

OPINION STATEMENT: Fetal arrhythmia is a common reason for referral to fetal cardiology. Fetal supraventricular tachycardia can be subdivided into several groups with the most common being re-entrant supraventricular tachycardia and atrial flutter. Fetal tachycardia can lead to hydrops fetalis, which increases the risk of fetal demise, perinatal morbidities, and premature delivery. The diagnosis of fetal tachycardia can be a challenge as a traditional electrocardiogram cannot be completed on a fetus, and other methods must be used by fetal echocardiogram. Several retrospective studies have been completed to determine the best treatment; however, there continues to be no consensus on the best option. Digoxin, flecainide, and sotalol are commonly used and have favorable results depending on gestational age, fetal well-being, and presence of hydrops. Treatment in a timely manner can convert supraventricular tachycardia to a normal fetal heart rate, and hydrops can resolve with delivery at term if the proper medications are used.

Flecainide versus digoxin for fetal supraventricular tachycardia: Comparison of two drug treatment protocols.

BACKGROUND: The optimal treatment for fetal supraventricular tachycardia (SVT) with 1:1 atrioventricular relationship is unclear. OBJECTIVE: We compared the effectiveness of transplacental treatment protocols used in 2 centers. METHODS: Pharmacologic treatment was used in 84 fetuses. Maternal oral flecainide was the primary therapy in center 1 (n = 34) and intravenous maternal digoxin in center 2 (n = 50). SVT mechanism was classified by mechanical ventriculoatrial (VA) time intervals as short VA or long VA. Treatment success was defined as conversion to sinus rhythm (SR), or rate control, defined as >15% rate reduction. RESULTS: Short VA interval occurred in 67 fetuses (80%) and long VA in 17 (20%). Hydrops was present 28 of 84 (33%). For short VA SVT, conversion to SR was 29 of 42 (69%) for digoxin and 24 of 25 (96%) for flecainide (P = .01). For long VA SVT, conversion to SR and rate control was 4 of 8 (50%) and 0 of 8, respectively, for digoxin, and 6 of 9 (67%) and 2 of 9 (cumulative 89%) for flecainide (P = .13). In nonhydropic fetuses, digoxin was successful in 23 of 29 (79%) and flecainide in 26 of 27 (96%) (P = .10). In hydrops, digoxin was successful in 8 of 21 (38%), flecainide alone in 6 of 7 (86%, P = .07 vs digoxin), and flecainide ± amiodarone in 7 of 7 (100%) (P = .01). Intrauterine or neonatal death occurred in 9 of 21 hydropic fetuses treated with digoxin (43%), compared to 0 of 7 (P = .06) treated with flecainide. CONCLUSIONS: Flecainide was more effective than digoxin, especially when hydrops was present. No adverse fetal outcomes were attributed to flecainide.

High-dose flecainide is the most effective treatment of fetal supraventricular tachycardia.

BACKGROUND: Fetal tachyarrhythmia can lead to fetal hydrops due to heart failure. Flecainide is often considered as second-line therapy when digoxin monotherapy fails, which is more likely in hydropic fetuses. Time to conversion to sinus rhythm (SR) is critical in cases presenting with hydrops. OBJECTIVE: The aim of this study was to evaluate the efficacy and time to conversion to SR of transplacental treatment, especially flecainide. METHODS: This is a retrospective observational study of 46 fetuses with fetal tachyarrhythmia. Treatment was either flecainide (n = 28, 60.9%), digoxin+flecainide combination (n = 4, 8.7%), or digoxin (n = 10, 21.7%). In 4 fetuses (8.7%), no treatment was necessary. RESULTS: In our study population, 26 of the 32 fetuses (81.2%) that were treated with flecainide as a first-line therapy (flecainide or digoxin+flecainide) converted to SR. The median time to conversion to SR was 3 days (range 1-7 days) with flecainide monotherapy and 11.5 days (range 3-14 days) with a combination therapy. Seventy-two percent (13/18) of hydropic fetuses and 90% (9/10) of nonhydropic fetuses converted to SR when treated with flecainide monotherapy. There was no statistical difference in rates of conversion to SR in hydropic and nonhydropic fetuses (P = .37) or time to conversion to SR in the 2 groups (P = .9). In the majority of the remaining fetuses, there was a partial response with decreased ventricular heart rates that were well tolerated. CONCLUSION: Flecainide is highly effective in achieving SR in hydropic and nonhydropic fetuses with supraventricular tachycardia in a median time of 3 days. In our opinion, flecainide should be considered as first-line therapy in fetal supraventricular tachycardia with and without hydrops.

Intrauterine management of fetal supraventricular tachycardia (SVT) with cardiac failure

Fetal arrhythmias are not uncommon in pregnancy. The diagnosis can be established on routine ultrasound scan. Fetal supraventricular tachycardia (SVT) is the most common cause of fetal tachycardia. If left undiagnosed and untreated, these fetuses may develop cardiac failure, hydrops fetalis and eventually death. We report two fetuses diagnosed antenatally to have fetal SVT. Both fetuses were in cardiac failure and were successfully treated with maternal administration of antiarrhythmic medications. Digoxin, and in severe instances, a combination with flecanaide significantly improved fetal outcomes and prevented fetal mortality. The long term prognosis of such patients are good.

A Case of Fetal Supraventricular Tachycardia with Fetal Ascites Treated by Antiarrhythmic Agent / 대한산부인과학회잡지

We experienced a case of fetal supraventricular tachycardia (SVT) with fetal ascites diagnosed at 29 weeks of gestation in 29 year-old primigravida woman. Transplacental fetal therapy with maternal oral antiarrhythmic agent (verapamil, diltiazem) resulted in restoration of normal fetal sinus rhythm and disappearance of fetal ascites. At birth, the infant did not show any cardiac arrhythmia and hydropic appearance.

Transplacental Fetal Therapy for a Case of Fetal Supraventricular Tachycardia which Caused Fetal Hydrops / 대한산부인과학회잡지

A case of fetal supraventricular tachycardia which caused fetal hydrops was diagnosed at 29 weeks of gestation by fetal echocardiography. Transplacental fetal therapy with ma-ternal intravenous digoxin administration resulted in restoration of normal fetal sinus rhythm and disappearance of fetal hydrops on 7th day after initiation of treatment when the mat-ernal serum digoxin level was 2.11 ng/mL. The fetus showed normal sinus rhythm when evaluated by fetal echocardiography during the remainder of pregnancy with maternal oral digoxin maintenence. At birth, the infant did not show any cardiac arrhythmia and hydropic appearance.