Isolated Atrioventricular Block in the Fetus

Abstract

Background-Isolated complete atrioventricular block in the fetus is a rare but potentially lethal condition in which the effect of steroid treatment on outcome is unclear. The objective of this work was to study risk factors associated with death and the influence of steroid treatment on outcome. Methods and Results-We studied 175 fetuses diagnosed with second-or third-degree atrioventricular block (2000 -2007) retrospectively in a multinational, multicenter setting. In 80% of 162 pregnancies with documented antibody status, atrioventricular block was associated with maternal anti-Ro/SSA antibodies. Sixty-seven cases (38%) were treated with fluorinated corticosteroids for a median of 10 weeks (1-21 weeks). Ninety-one percent were alive at birth, and survival in the neonatal period was 93%, similar in steroid-treated and untreated fetuses, regardless of degree of block and/or presence of anti-Ro/SSA. Variables associated with death were gestational age Ͻ20 weeks, ventricular rate Յ50 bpm, fetal hydrops, and impaired left ventricular function at diagnosis. The presence of Ն1 of these variables was associated with a 10-fold increase in mortality before birth and a 6-fold increase in the neonatal period independently of treatment. Except for a lower gestational age at diagnosis in treated than untreated (23.4Ϯ2.9 versus 24.9Ϯ4.9 weeks; Pϭ0.02), risk factors were distributed equally between treatment groups. Two-thirds of survivors had a pacemaker by 1 year of age; 8 children developed cardiomyopathy. Conclusions-Risk factors associated with a poor outcome were gestation Ͻ20 weeks, ventricular rate Յ50 bpm, hydrops, and impaired left ventricular function. No significant effect of treatment with fluorinated corticosteroids was seen. (Circulation.

Neonatal Lupus Erythematosus

“…Previously reported fetal risk factors associated with increased mortality include early diagnosis (before 20 weeks gestational age), lower ventricular rate (less than 50 beats per minute), echocardiographic evidence of hydrops, echocardiographic evidence of endocardial fibroelastosis, and impaired left ventricular function at diagnosis [105,106].…”

Outcomes of fetal echocardiographic surveillance in anti‐SSA exposed fetuses at a large fetal cardiology center

“…27,8,2 The postulated mechanism of action is that fluorinated steroids are able to resist degradation by placental enzymes and may decrease the inflammatory myocarditis that precedes fibrosis. 28 A study of 120 SSA exposed fetuses did not show evidence of prevention of complete AV block when initiated after firstdegree AV block was noted.…”

“…While only 1-2% of exposed fetuses develop third-degree atrioventricular (AV) block, fetuses with AV block and cardiomyopathy suffer high morbidity and mortality. [1][2][3][4] Current fetal echocardiographic surveillance methods are costly and do not accurately predict which fetuses will develop progressive AV block and cardiomyopathy. On the basis of the possibility of poor outcome if AV block occurs, fetal echocardiography is recommended for maternal anti-SSA/anti-SSB antibodies.…”

Almanac 2012: Congenital heart disease. The national society journals present selected research that has driven recent advances in clinical cardiology

“…12 Risk factors for poor outcome were gestation <20 weeks, ventricular rate <50/min, hydrops and impaired ventricular function. No significant effect of treatment with corticosteroids was seen.…”