[Fetal bradycardia: a retrospective study in 9 Spanish centers]. / Bradicardia fetal: estudio multicéntrico retrospectivo en 9 hospitales españoles.

OBJECTIVE: The aim of this study is to review the current management and outcomes of fetal bradycardia in 9 Spanish centers. METHODS: Retrospective multicenter study: analysis of all fetuses with bradycardia diagnosed between January 2008 and September 2010. Underlying mechanisms of fetal bradyarrhythmias were studied with echocardiography. RESULTS: A total of 37 cases were registered: 3 sinus bradycardia, 15 blocked atrial bigeminy, and 19 high grade atrioventricular blocks. Sinus bradycardia: 3 cases (100%) were associated with serious diseases. Blocked atrial bigeminy had an excellent outcome, except for one case with post-natal tachyarrhythmia. Of the atrioventricular blocks, 16% were related to congenital heart defects with isomerism, 63% related to the presence of maternal SSA/Ro antibodies, and 21% had unclear etiology. Overall mortality was 20% (37%, if terminations of pregnancy are taken into account). Risk factors for mortality were congenital heart disease, hydrops and/or ventricular dysfunction. Management strategies differed among centers. Steroids were administrated in 73% of immune-mediated atrioventricular blocks, including the only immune-mediated IInd grade block. More than half (58%) of atrioventricular blocks had a pacemaker implanted in a follow-up of 18 months. CONCLUSIONS: Sustained fetal bradycardia requires a comprehensive study in all cases, including those with sinus bradycardia. Blocked atrial bigeminy has a good prognosis, but tachyarrhythmias may develop. Heart block has significant mortality and morbidity rates, and its management is still highly controversial.

[Dilated cardiomyopathy secondary to atrial ectopic tachycardia]. / Miocardiopatía secundaria a taquicardia auricular ectópica.

Ectopic atrial tachycardia is an uncommon cause of supraventricular tachycardia in children. It can resolve spontaneously or induce dilated cardiomyopathy. It is important to recognize this entity as a reversible cause of dilated cardiomyopathy, characterized by the presence of an abnormal focus located in the atrial myocardium and distinct to sinus node. Treatment strategies include the use of antiarrhythmic drugs, radiofrequency ablation, and, in patients refractory to medical treatment, surgical resection of the ectopic focus. We describe a patient with dilated cardiomyopathy due to an atrial ectopic focus and its resolution after medical treatment.