Fetal dysrhythmias

Abstract

Fetal cardiac dysrhythmias are potentially life-threatening conditions. However, intermittent extrasystoles, which are frequently encountered in clinical practice, do not require treatment. Sustained forms of brady- and tachyarrhythmias might require fetal intervention. Fetal echocardiography is essential not only to establish the diagnosis but also to monitor fetal response to therapy. In the last decade, improvements in ultrasound methodology and new diagnostic tools have contributed to better diagnostic accuracy and to a greater understanding of the electrophysiological mechanisms involved in fetal cardiac dysrhythmias. The most common form of supraventricular tachycardia - that caused by an atrioventricular re-entry circuit - should be differentiated from other forms of tachyarrhythmias, such as atrial flutter and atrial ectopic tachycardia. Ventricular tachycardia is rare in the fetus. Sustained tachycardias, intermittent or not, might be associated with the development of congestive heart failure and hydrops fetalis. Prompt treatment with either anti-arrhythmic drugs or delivery must be considered. Persistent fetal bradycardias associated with complete heart block are also potentially dangerous, whereas bradyarrhythmia due to blocked ectopy is well tolerated in pregnancy. Heart block can be associated with maternal anti-Ro/La autoantibodies or develop in fetuses with left atrial isomerism or with malformations involving the atrioventricular junction. The treatment of fetuses with immune-mediated heart block remains debatable. The use of antenatal steroid therapy is not widely accepted and there is concern over the risks and benefits of its use in the fetus. Direct fetal cardiac pacing has rarely been attempted.

Gestão pré-natal e resultados da taquicardia juncional ectópica acelerado e hidropisia

“…The safety of the mother is of great concern when managing fetal tachycardia, as administration of antiarrhythmic drugs for intrauterine treatment may cause pro-arrhythmia and threaten the mother. Digoxin has been widely accepted as the mainstay of therapy because of its safety and convenient administration 1,2,5 . Flecainide, sotalol and amiodarone has also been used in the treatment of fetal tachyarrhythmias 5,9,10 .…”

“…Digoxin has been widely accepted as the mainstay of therapy because of its safety and convenient administration 1,2,5 . Flecainide, sotalol and amiodarone has also been used in the treatment of fetal tachyarrhythmias 5,9,10 . However, more serious side effects on both mother and fetus have been a concern 5 .…”

“…Flecainide, sotalol and amiodarone has also been used in the treatment of fetal tachyarrhythmias 5,9,10 . However, more serious side effects on both mother and fetus have been a concern 5 . The outcome in congenital JET shows that is a malignant tachyarrhythmia causing tachycardia-induced cardiomyopathy and sudden death 6 .…”

“…This situation is associated with significant morbidity and mortality [1][2][3][4] . In general, the diagnosis and assessment of these dysrhythmias can be accurately made using high-resolution 2-D ultrasound using M mode and Doppler assessment of the relationship between the atrial and ventricular contractions 5 . Junctional ectopic tachycardia (JET) is a rare form of fetal tachyarrhythmia, which usually occurs in the setting of surgery for congenital heart disease 6 .…”

Non-immune hydrops foetalis due to foetal tachyarrhythmia-management with transplacental amiodarone

“…Foetal echocardiography is essential to diagnose the exact nature of tachycardia, to rule out underlying structural defects and to monitor response to therapy. 3,8 Our patient was diagnosed to have supraventricular tachycardia (SVT) without any underlying structural cardiac defects.…”