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

Abstract

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. K E Y W O R D S atrial flutter, fetal tachycardia, supraventricular tachycardia, therapy SUPPORTING INFORMATION Additional supporting information may be found online in the Supporting Information section. How to cite this article: O'Leary ET, Alexander ME, Bezzerides VJ, et al. Low mortality in fetal supraventricular tachycardia: Outcomes in a 30-year single-institution experience.

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

“…Overall, this dualagent regimen achieved rate reversion in 22 of 27 (81.5%) cases. Our results are comparable to other published series which report success rates of 59-90% using digoxin, flecainide, or sotalol in combination [9][10][11][12][13]. Our results also indicate that in almost 1 in 3 cases without hydrops and 1 in 2 cases with hydrops, initial monotherapy failed thus requiring progression to second-line polytherapy.…”

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

“…Any discrepancies were resolved between two reviewers by discussion until consensus was reached. Among the 26 included studies, one was a prospective study, and 25 were retrospective studies ( van Engelen et al, 1994 ; Frohn-Mulder et al, 1995 ; Naumburg et al, 1997 ; Lisowski et al, 2000 ; Oudijk et al, 2000 ; Ebenroth et al, 2001 ; Jouannic et al, 2002 ; Krapp et al, 2002 ; Boldt et al, 2003 ; Jouannic et al, 2003 ; Oudijk et al, 2003 ; D'Alto et al, 2008 ; Pézard et al, 2008 ; Lulic Jurjevic et al, 2009 ; Hahurij et al, 2011 ; Shah et al, 2012 ; Uzun et al, 2012 ; van der Heijden et al, 2013 ; Ekman-Joelsson et al, 2015 ; Sridharan et al, 2016 ; Strizek et al, 2016 ; Ekiz et al, 2018 ; Karmegeraj et al, 2018 ; Miyoshi et al, 2019 ; O'Leary et al, 2020 ; Tunca Sahin et al, 2021 ). Only one randomized controlled trial (RCT; www.fasttherapytrial.com ) (Edgar Jaeggi, MD, etc.)…”

Treatment of Fetal Arrhythmias

“…The practice of fetal medicine centers varies widely in respect to the drug chosen as initial treatment for fetal SVT. All of the following drugs: digoxin, flecainide, sotalol, and amiodarone have been used as first-line transplacental therapy in SVT [ 1 , 9 , 10 , 12 , 13 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. The effectiveness of transplacental treatment is dependent on pharmacokinetics, its capacity to cross the placenta, and fetal bioavailability [ 1 , 5 ].…”

“…For a longtime, digoxin has been used as first line therapy for fetal SVT, but none of the recent studies and meta-analyses supports this idea [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. Nonetheless, digoxin has some practical advantages if treatment is considered for moderate fetal disease [ 1 , 3 ].…”

“…In a meta-analysis of 21 studies on the transplacental treatment of fetal tachycardia, both flecainide and sotalol were more effective than digoxin for conversion of any fetal tachycardia to sinus rhythm, and the difference was greatest in hydropic fetuses [ 44 ]. The experience of a large center with very good results in fetal SVT treatment shows that drug change or multidrug therapy were necessary in 68% of cases where digoxin was used as first-line therapy [ 45 ]. In the particular setting of atrial flutter, treatment with flecainide or sotalol aims to terminate the arrhythmia, while treatment with digoxin aims to slow the ventricular rate.…”