Life-threatening rhythm and conduction disorders by a child with MIS-C

ABSTRACT

Background and Aim: Cardiac involvement is seen in the majority of cases with multisystem inflammatory syndrome in children (MIS-C). Various rhythm and conduction disturbances, as well as repolarization abnormalities, have been described by more than 50% of the patients, while there are few cases with complete heart block or with asystole. Method(s) Case report Results: 8-year old girl presented with a 5-day history of fever, cough, headache, and abdominal pain. Because of the critical con-dition, with respiratory insufficiency and heart failure symptoms, the child was intubated and started on inotropic support. ECG showed complete AV-block with a ventricular rate of 75/min and with ST-T changes;echocardiography revealed dilated left ventricle with reduced contractility, CT-scan of the lungs showed bilateral pneumonia, the inflammatory markers were elevated, in combination with high troponin levels, and positive SARS-CoV2-IgG antibodies. The diagnosis MIS-C was made and treatment with immunoglobulins, antibiotics, corticosteroids, and anticoagulants was initiated. During the next 2 days, the cardiac function deteriorated further, and while still on mechanical ventilation and inotropic support, extreme bradycardia with a ventricular rate of 35/min was regis-tered, and the patient was indicated for temporary emergency pac-ing. Upon induction of anesthesia, the child became asystolic, requiring extensive resuscitation. After circulation recovery, the ECG showed nodal tachycardia with a heart rate of 140-170/min. A temporary transvenous pacemaker (PM) was inserted, and the patient was started on intravenous amiodarone which resulted in a slower ventricular rate of 70/min. 3 days later sinus rhythm was restored, with first-degree AV-block, which allowed removal of the PM 5 days after its insertion. Left ventricular dimensions were normalized and contractility remained low-normal (EF 56%). During the 6-month follow-up, the ECG and the Holter-monitoring showed sinus rhythm with first-degree AV-block. Magnetic resonance imaging (MRI) on day 15 of the hospital stay demonstrated scattered areas of myocarditis and ischemia predominantly in the left ventricle, as well as thickening of the basal septum. Six months later the MRI changes were reduced but still persistent. Conclusion(s) MIS-C can present with serious and life-threatening rhythm and conduction disturbances in children;this is why extensive cardiac monitoring is obligatory by all patients.