Anti‐Ro/SSA antibody‐related atrioventricular block‐induced torsade de pointes

Abstract

Ro/SSA antibody, complete atrioventricular block, pacemaker implantation, QT prolongation, torsade de pointes. Congenital complete atrioventricular block (CAVB) is a rare but life-threatening disease. Most CAVB cases are caused by the transfer of maternal anti-Ro/SS-A antibody to the fetus through the placenta. Anti-Ro/SS-A antibody associated CAVB generally occurs in the neonatal period; however, it may occasionally occur later. Recently, it has been reported that anti-Ro/SS-A antibody contributes not only to CAVB but also to the development of sinus bradycardia or QT prolongation. Here we report an infant case of refractory torsade de pointes (TdP), which was controlled by a pacemaker management. A 2-year-old boy visited our hospital because he suffered from bronchitis. Nebulized beta stimulant, expectorant, and leukotriene receptor antagonist were administered. During the physical examination, we noticed the patient's bradycardia. We performed an electrocardiogram (ECG) and significant bradycardia and QT prolongation were confirmed (Fig. 1a). A medical history taken from the mother revealed that she was found to be positive for the anti-Ro/SSA antibody and the patient had been noted as having severe bradycardia during fetal period in another institution. We therefore retrieved his previous ECG during his neonatal period and reconfirmed the findings (Fig. 1b). An ECG that was performed immediately after his birth showed no abnormal findings, so he did not receive clinical follow up after the neonatal period. We requested further investigation in the initial institution, but the recorded ECG revealed a normal corrected QT interval (Fig. 1c). Holter ECG was therefore scheduled. Six months after suffering from bronchitis, he was referred to our emergency room because of febrile seizure. An ECG detected TdP (Fig. 1d-1), and magnesium sulfate was infused immediately. Subsequent ECG after elimination of TdP

A rare case with fetal autoimmune heart block and KNCH2 variant–induced long QT syndrome: a controversial opinion on prenatal management strategy

“…However, there are some situations where the use of such therapeutic strategies leads to complicated issues. Mizuno et al reported an infant case of CAVB with TDP and no genetic evidence on LQTS of any variants in KCNQ1 , KCNH2 , or SCN5A [ 13 ]. In a study by Michaelsson et al, 7% of patients were identified to have prolonged QT intervals (corrected QT interval > 450 ms) [ 14 ].…”

Anti-Ro/SSA Antibodies and the Autoimmune Long-QT Syndrome

“…Moreover, AlTwajery et al ( 61 ) demonstrated that among 41 children affected with SLE, anti-Ro/SSA-positivity was associated with a higher prevalence of ECG abnormalities, particularly QTc prolongation > 450 ms. Finally, three cases of marked QTc prolongation complicated with ventricular tachycardia/TdP in infants from anti-Ro/SSA-positive mothers with aCHB are reported ( 63 – 65 ).…”