Atrioventricular Conduction Abnormalities in Multisystem Inflammatory Syndrome in Children

Abstract

Cardiac manifestations in multisystem inflammatory syndrome in children (MIS-C) can include coronary artery aneurysms, left ventricular systolic dysfunction, and electrocardiographic disturbances. We report the clinical course of three children with MIS-C while focusing on the unique considerations for managing atrioventricular conduction abnormalities. All initially had normal electrocardiograms but developed bradycardia followed by either PR prolongation or QTc elongation. Two had mild left ventricular ejection fraction dysfunction prior to developing third-degree heart block and/or a junctional escape rhythm; one had moderate left ventricular systolic dysfunction that normalized before developing a prolonged QTc. On average, our patients presented to the hospital 4 days after onset of illness. Common presenting symptoms included fevers, abdominal pain, nausea, and vomiting. Inflammatory and coagulation factors were their highest early on, and troponin peaked the highest within the first two days; meanwhile, peak brain-natriuretic peptide occurred at hospital days 3-4. The patient’s lowest left ventricular ejection fraction occurred at days 5-6 of illness. Initial electrocardiograms were benign with PR intervals below 200 milliseconds (ms); however, collectively the length of time from initial symptom presentation till when electrocardiographic abnormalities began was approximately days 8-9. When comparing the timing of electrocardiogram changes with trends in c-reactive protein and brain-natriuretic peptide, it appeared that the PR and QTc elongation patterns occurred after the initial hyperinflammatory response. This goes in line with the proposed mechanism that such conduction abnormalities occur secondary to inflammation and edema of the conduction tissue as part of a widespread global myocardial injury process. Based on this syndrome being a hyperinflammatory response likely affecting conduction tissue, our group was treated with different regimens of intravenous immunoglobulin, steroids, anakinra, and/or tocilizumab. These medications were successful in treating third-degree heart block, prolonged QTc, and a junctional ectopic rhythm.

Cardiovascular Spectrum and Cardiac Biomarkers in Pediatric Inflammatory Multisystem Syndrome with Kawasaki-Like Disease - Our Experience During the COVID-19 Pandemic in the West Part of Romania

“…changes in 60% of patients, higher than in the European study where it was 20%, but the same with the report from the UK 18,24 . We stated changes in ECG during hospitalization with long QT in 7% of patients, also higher than in other studies (4.5%), bradycardia in 7% of patients, not mentioned in other studies, tachybrady arrhythmia in 3% of patients, also not mentioned, and grade I/II degree atrio-ventricular block in 3%, higher than in literature where it varies between 1.7-2.1% 18,[24][25][26] . The ECG stabilized before discharge in all studies, like our fi ndings.…”

Arrhythmia and COVID-19 in children

“…Table 2 shows the clinical characteristics, management, and outcomes of the patients reported in the literature. Bradyarrhythmia was reported in 16%-20% of patients with MIS-C. 56,59,60) MIS-C usually presents several weeks after a viral infection, and a dysregulated inflammatory response is the presumed pathophysiology. 41) Therefore, inflammation of conduction tissue and edema adjacent to the AV nodal or His-Purkinje system can be assumed to contribute to the conduction abnormalities.…”

“…56,59,63) In rare instances, some children required permanent pacemaker implantation, and the first-degree AV block persisted at the time of discharge in some, suggesting the possibility of irreversible damage to the conduction tissue. 59,64) Therefore, patients with conduction abnormalities require intensive electrocardiogram monitoring during hospitalization and long-term follow-up after discharge. 56,60,61) The therapeutic effect of anti-inflammatory drugs on AV block or the preventive effect on the progression to a complete AV block remains unknown because all related studies were retrospective.…”

“…There have been reports of QT prolongation or repolarization abnormalities in patients with COVID-19 and MIS-C irrespective of QT-prolonging drug use. 44,59,61,[65][66][67][68] Repolarization abnormalities, with myocardial injury from acute myocarditis in COVID-19 and a hyperinflammatory state in MIS-C, can increase the risk of malignant arrhythmia in patients with inherited arrhythmia despite no reports to date. Pawar et al 69) reported neonates with multiple inflammatory syndromes presenting with QTc prolongation with a 2:1 AV block who were born to mothers with a history of COVID-19.…”

“…Table 2 shows the clinical characteristics, management, and outcomes of the patients reported in the literature. Bradyarrhythmia was reported in 16%–20% of patients with MIS-C [ 56 , 59 , 60 ]. MIS-C usually presents several weeks after a viral infection, and a dysregulated inflammatory response is the presumed pathophysiology [ 41 ].…”