Successful treatment of neonatal atrial flutter by synchronized cardioversion: case report and literature review

What Is the Optimal Digoxin Level? Challenging Case of Fetal Atrial Flutter Treatment in a Monochorionic Diamniotic Twin

Background: Atrial flutter is an infrequent yet potentially fatal arrhythmia. Digoxin is the preferred first-line treatment for fetal atrial flutter due to its efficacy and favorable safety profile. The optimal digoxin serum target level for neonatal atrial flutter management remains uncertain, with the standard target level ranging from 1.0 to 2.0 ng/mL due to potential toxicity concerns above this threshold. Case Presentation: We present a case of atrial flutter in a fetus within a monochorionic diamniotic (MCDA) twin pregnancy that was successfully managed using a higher-than-standard target level of digoxin. A 34-year-old nulliparous woman was referred to our institution at 31 + 3 weeks of gestation due to fetal distress in an MCDA twin pregnancy. Fetal echocardiography revealed a ventricular rate of 214 bpm in twin A, while twin B exhibited no abnormal findings. Conclusions: Our case highlights a distinct correlation between the serum digoxin level and its impact on atrial flutter. A higher target serum level of digoxin may be necessary to achieve sinus conversion due to the unique maternal and fetal circulatory characteristics in MCDA pregnancies.

Cardiac Arrhythmias Requiring Electric Countershock during the Neonatal Period-A Systematic Review

BACKGROUND

In neonates, cardiac arrhythmias are rare. Electric countershock therapy is an effective alternative to drug therapy for neonatal arrhythmias. There are no randomized controlled studies investigating electric countershock therapy in neonates.

OBJECTIVE

To identify all studies and publications describing electric countershock therapy (including defibrillation, cardioversion, and pacing) in newborn infants within 28 days after birth, and to provide a comprehensive review of this treatment modality and associated outcomes.

METHODS

For this systematic review we searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Cumulative Index to Nursing and Allied Health Literature (CINAHL). All articles reporting electric countershock therapy in newborn infants within 28 days after birth were included.

RESULTS

In terms of figures, 113 neonates who received electric countershock due to arrhythmias were reported. Atrial flutter (76.1%) was the most common arrhythmia, followed by supraventricular tachycardia (13.3%). Others were ventricular tachycardia (9.7%) and torsade de pointes (0.9%). The main type of electric countershock therapy was synchronized cardioversion (79.6%). Transesophageal pacing was used in twenty neonates (17.7%), and defibrillation was used in five neonates (4.4%).

CONCLUSION

Electric countershock therapy is an effective treatment option in the neonatal period. In atrial flutter especially, excellent outcomes are reported with direct synchronized electric cardioversion.

Clinical characteristics and outcomes of atrial flutter in neonates

BACKGROUND

Atrial flutter is an uncommon arrhythmia that can cause severe morbidity, including heart failure and even death in refractory cases. This study investigated the clinical characteristics, treatment, and long-term outcomes of patients with neonatal atrial flutter and its association with heart failure.

METHODS

We retrospectively reviewed atrial flutter cases observed in our center between 1999 and 2021 and analyzed the clinical characteristics, treatment, and recurrence according to the presence of heart failure.

RESULTS

The study comprised 15 patients with atrial flutter, with median bodyweight and gestational age of 2.7 kg, 37+4 weeks, respectively. Twelve patients were diagnosed with atrial flutter on the first day of life. The median atrial and ventricular rates were 440/min, 220/min, respectively. Four patients exhibited congestive heart failure. Episodic recurrence was noted in five patients and occurred at a higher rate in patients with congestive heart failure (p = 0.004). Antiarrhythmic drugs for maintenance treatment were administered more often in patients with heart failure (p = 0.011). Initial treatment included direct current cardioversion (n = 9), digoxin (n = 4), and observation (n = 2). Four patients treated with cardioversion experienced recurrence during the neonatal period, and none of those treated with digoxin experienced recurrence. The median follow-up duration was 7 years, during which no atrial flutter recurrence was evident.

CONCLUSION

Neonates with congestive heart failure had a higher recurrence of atrial flutter. Direct current cardioversion is the most reliable treatment for neonatal atrial flutter, whereas digoxin may be a viable treatment option in refractory and recurrent cases.

Successful management of fetal atrial flutter at term pregnancy with postnatal electrocardioversion

Fetal atrial flutter is a lethal tachyarrhythmia with a 10% mortality rate. Diagnosis is made with echocardiography, and management should be multidisciplinary with obstetricians, fetal cardiologists, and specialist neonatologists.