The challenge of fetal dysrhythmias: echocardiographic diagnosis and clinical management.
ABSTRACT The present study aimed to evaluate the management of fetal cardiac dysrhythmias based on prior identification of the underlying electrophysiological mechanism.
We studied 36 consecutive fetuses with cardiac dysrhythmia. Rhythm diagnosis was based on M-mode, pulsed wave Doppler and tissue Doppler imaging (TDI). Only fetuses with: (i) incessant tachycardia (> 12 h) and mean ventricular rate > 200 beats/min, (ii) signs of left ventricular dysfunction, or (iii) hydrops, were treated using oral maternal drug therapy.
The mean gestational age at diagnosis was 24.3 +/- 4.5 weeks. Twenty-one fetuses had tachycardia with a 1: 1 atrial-ventricular (AV) conduction. Based on ventricular-atrial interval, prenatal diagnosis was: permanent junctional reciprocating (n = 6), atrial ectopic (n = 6) or atrial-ventricular re-entry tachycardia (n = 9). One had atrial flutter, one ventricular tachycardia and four congenital AV block. Nine showed premature atrial or ventricular beats. Fifteen fetuses with incessant tachycardia, left ventricular dysfunction or hydrops were prenatally treated with maternal administration of digoxin, sotalol or flecainide. The total success rate (sinus rhythm or rate control) was 14/15 (93%). Seven fetuses were hydropics. Three of these died (one at 28 weeks of gestation, two in the first week of life). The prenatal diagnosis of dysrhythmia was confirmed at the birth in 31 of 35 live-born. No misdiagnosis was made using TDI. At 3 +/- 1.1-year follow-up, 33/35 children were alive and well.
Fetal echocardiography could clarify the electrophysiological mechanism of fetal cardiac dysrhythmias and guide the therapy.
Full-textDOI: · Available from: Michele D'Alto, May 29, 2015
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ABSTRACT: The diagnosis and management of prenatal tachyarrhythmias is well established; however, the postnatal course and outcomes are not. The purpose of our study was to review the natural history of patients with fetal tachycardia, determine the incidence of postnatal arrhythmias, and determine whether there are factors to predict which fetuses will develop postnatal arrhythmias. A retrospective chart review of patients with fetal tachyarrhythmias investigated at British Columbia Children's and Women's Hospitals between 1983 and 2010 was conducted. Sixty-nine mother-fetus pairs were eligible for the study. Fifty-two had fetal supraventricular tachycardia, and 17 had fetal atrial flutter. Conversion to sinus rhythm occurred prenatally in 52 % of patients. Postnatal arrhythmia occurred in two thirds of patients, with 82 % of those cases occurring within the first 48 h of life. Hydrops fetalis, female sex, and lack of conversion to sinus rhythm was predictive of postnatal arrhythmia (P = 0.01, P = 0.01, and P = 0.001, respectively). Conversion to sinus rhythm prenatally did not predict postnatal arrhythmia. Median duration of treatment was 9 months. Two postnatal deaths of unknown etiology occurred. Two thirds of all patients with prenatal tachycardia will develop postnatal arrhythmia. Prenatal factors that predict postnatal arrhythmia include hydrops, sex, and whether or not conversion to sinus rhythm occurred prenatally. The majority of patients with postnatal arrhythmia present within 48 h of life, which has clinical implications for monitoring. Postnatal outcome is generally very good with most patients being weaned off medication in 6-12 months.Pediatric Cardiology 05/2012; 34(1). DOI:10.1007/s00246-012-0392-7 · 1.55 Impact Factor
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ABSTRACT: The human fetal heart develops arrhythmias and conduction disturbances in response to ischemia, inflammation, electrolyte disturbances, altered load states, structural defects, inherited genetic conditions, and many other causes. Yet sinus rhythm is present without altered rate or rhythm in some of the most serious electrophysiological diseases, which makes detection of diseases of the fetal conduction system challenging in the absence of magnetocardiographic or electrocardiographic recording techniques. Life-threatening changes in QRS or QT intervals can be completely unrecognized if heart rate is the only feature to be altered. For many fetal arrhythmias, echocardiography alone can assess important clinical parameters for diagnosis. Appropriate treatment of the fetus requires awareness of arrhythmia characteristics, mechanisms, and potential associations. Criteria to define fetal bradycardia specific to gestational age are now available and may allow detection of ion channelopathies, which are associated with fetal and neonatal bradycardia. Ectopic beats, once thought to be entirely benign, are now recognized to have important pathologic associations. Fetal tachyarrhythmias can now be defined precisely for mechanism-specific therapy and for subsequent monitoring of response. This article reviews the current and future diagnostic techniques and pharmacologic treatments for fetal arrhythmia.Nature Reviews Cardiology 05/2010; 7(5):277-90. DOI:10.1038/nrcardio.2010.32 · 10.15 Impact Factor
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ABSTRACT: Background Transplacental flecainide is an established therapy for fetal supraventricular tachycardia (SVT) but there is a paucity of data regarding the dose-response relationship. Objectives The aim of this study was to investigate the relationship between maternal flecainide concentrations, arrhythmia control and adverse fetal effects in fetal SVT. Methods Fetuses with SVT treated with transplacental flecainide at our tertiary fetal cardiology unit between 1997 and 2012 were retrospectively studied. The maternal trough flecainide concentrations throughout treatment were collated and clinical notes were reviewed to ascertain the response to therapy and fetal outcome. Results 33 fetuses were treated at a median (range) gestation of 28 weeks (20-38). The median fetal heart rate was 250/minute (range: 207-316). One patient was lost to follow-up and this fetus is excluded from further analysis. 25/32 (78%) fetuses converted to sinus rhythm. The median time to conversion to sinus rhythm was 3 days (range: 2-12). The median flecainide concentration was 460micrograms/litre (range: 250-866) at conversion to sinus rhythm. Flecainide concentrations were not significantly different between responders and non-responders (p=0.849). 12/14 hydropic and 13/18 non-hydropic fetuses converted to sinus rhythm with similar flecainide concentrations (p=0.316). No fetus achieved cardioversion with a maternal serum flecainide concentration below 250micrograms/litre. No fetus died whilst being treated with flecainide. Conclusions The clinical response to flecainide appears good, even in hydropic fetuses. Trough maternal flecainide concentrations, once therapeutic, do not predict cardioversion in the fetus with SVT. Flecainide therapy appears both safe and effective for the fetus when monitored appropriately.Heart Rhythm 11/2014; 11(11). DOI:10.1016/j.hrthm.2014.07.031 · 4.92 Impact Factor