Subscribe to RSS
DOI: 10.1055/s-0044-1780742
Conduction in Distress—Treatment of an AV-Node Going Crazy
Background: Congenital heart block (CHB) is a rare, but well-known complication among pregnancies of mothers with autoimmune disease (approx. 2% of autoantibody-positive pregnancies, mainly Anti-SSA/Ro, Anti-SSB/La). Mortality rate is as high as 20% in newborns and 64% of patients will require a pacemaker over time. Clinical spectrum ranges from asymptomatic AV-block I° to (more often) high grade AV-block or other arrhythmias. Hydrops fetalis, endocardial fibroelastosis or valvular disease are feared comorbidities. Histologically an inflammation with subsequent fibrosis of the conduction system (especially the AV-node) has been demonstrated. Optimal management strategies are a matter of ongoing debate.
Methods: At 23+3 weeks gestational age a 2:1 AV-Block (V-Rate 87 bpm, A-Rate 165 bpm) was observed in the fetus of a women with known Sjögren syndrome. No other cardiac pathologies were noted and the diagnosis of CHB was made. Mother’s therapy consisted of Hydroxychloroquine + ASS. SSA/Ro and SSB/LA antibodies were significantly elevated. Delivery in 39+3 weeks, postnatal transition was uneventful. Heart rates were 60–80 bpm (AV-Block 2nd degree) with short episodes of intermittent sinus rhythm (150–170 bpm). The child was clinically asymptomatic and a wait-and-see approach was taken. In a regular control (1 month after birth) intermittent tachycardia up to 230 bpm was noted. Junctional ectopic tachycardia (JET) was suspected and therapy options were difficult putting the low baseline heart rate into account. Therapy with IVIG (2 g/kg) was initiated and tachycardia improved rapidly. After another relapse (2 weeks later) another course of IVIG (1 g/kg) was administered and no further JET-episodes occurred. Until today (3 years later) the patient is well and not taking any medication. In accordance with the current guidelines no pacemaker has been implemented yet. In the meantime, with repetitive immunoadsorption in pregnancy, the mother gave birth to a healthy girl.
Conclusion: Autoantibody induced inflammation of the conduction system might destroy AV-nodal cells and also induce ectopic tachycardia. In the difficult situation of AV block-related bradycardia and concomitant tachycardias therapy with IVIG can be a feasible option. More than 50% of the patients with CHB require a pacemaker and the time of implantation should be carefully determined. Furthermore, Immunoadsorption seems to be a preventive option in high-risk pregnancies.
Publication History
Article published online:
13 February 2024
© 2024. Thieme. All rights reserved.
Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany