Brugada pattern revealed during SARS-COV-2-related multi-systemic inflammatory syndrome in a 6-year-old child

Background

Brugada syndrome is an inherited form of dysrhythmia characterised by electrocardiographic features of right bundle block, characteristic ST-segment elevation on leads V1–V3 and a normal Q-T interval.1 The syndrome is one of the leading causes of sudden cardiac death in children, since it determines an increased risk of polymorphic ventricular tachyarrhythmias.2 The prevalence of Brugada syndrome is extremely low (0.0098%) in the paediatric population.3 Children with the Brugada syndrome are usually healthy and unaware of their condition; nevertheless, fever, alcohol and certain medications may act as provocative triggers inciting life-threatening arrhythmias. In this report, we present a case of a 6-year-old child in which the Brugada pattern was found concomitantly with the diagnosis of COVID-19-related multisystem inflammatory syndrome in children (MIS-C); moreover, a resolution of electrocardiographic abnormalities was obtained subsequently to therapy with steroids and immunoglobulins.

Case presentation

A 6-year-old Caucasian boy was admitted to the paediatric emergency department with fever (39.0°C), abdominal pain and diarrhoea. He had also presented a generalised erythematous macular rash with palmar-plantar involvement 2 days before. Vital signs at admission were: cardiac rate 120 bpm, peripheral oxygen saturation 99% in room air and respiratory rate 28 /min. Systemic examination highlighted dark infraorbital circles and hyperaemic throat.

The fever had started 5 days prior hospitalisation. A recent exposure to SARS-CoV-2 also emerged, since the child’s parents were tested positive to real-time PCR 20 days prior hospital admission; the child was not tested at that time, and his nasopharyngeal swab performed on admission resulted negative for SARS-CoV-2. The child’s medical history was unremarkable. No episodes of sudden cardiac death were reported in the family history.

Investigations

Complete blood counts revealed haemoglobin 118 g/L (N: 110–147 g/L), platelet count 179×10⁹ (N: 170×10⁹–450×10⁹), total leucocyte count 7.61×10⁹ (N: 5.00×10⁹–13.50×10⁹), with differential leucocyte count of neutrophils 78.3%; lymphocytes 17.4%; monocytes 3.3% and eosinophils 0.6%. A laboratory evidence of inflammation was found: in particular, C reactive protein was 66.6 mg/dL (N: <5.0 mg/dL); procalcitonin 17.26 mg/mL (N: <0.5 ng/mL); fibrinogen 648 mg/dL (N: 200–400 mg/dL); D-dimer 3061 ng/mL (N: <500 ng/mL); lactic acid dehydrogenase 331 IU/L (N: 250 IU/L); ferritin 533 ng/mL (N: 21–275 ng/mL); interleukin 6 227.2 ng/L (N:<4.4). A mild hypokalaemia (3.0 mmol/L; N: 3.5–5.0 mmol/L) was also detected and parenteral potassium supplementation was given. Test for SARS-CoV-2 antibodies was conducted using immunoenzymatic assays and reported elevated levels of IgG (5.2; positive if >1.1) and IgA (9.7; positive if >1.1).

A 12-lead ECG performed on admission showed a suggestive pattern of type 1 Brugada syndrome (figure 1). Heart rate was 122 bpm. PR and QT intervals were normal. Transthoracic echocardiogram did not found abnormalities. Chest radiograph was normal. Abdominal echography revealed the presence of a small volume of free fluid in the subhepatic space and in the pelvis. Blood and urine cultures were also performed, returning negative.

Treatment

The patient fulfilled all criteria for MIS-C4 and, after the initial management, he was admitted in the paediatric intensive care unit, where multiparameter (ECG, peripheral oxygen saturation, blood pressure, respiratory rate) continuous non-invasive monitoring and supportive care started. Anti-inflammatory medications (methylprednisolone 2 mg/kg/die and human immunoglobulin 2 g/kg over 12 hours on single administration), anticoagulation treatment (low-molecular-weight heparin 100 UI/kg/die) and aspirin 5 mg/kg/die were administered. Antibiotic was used while awaiting bacterial cultures.

Outcome and follow-up

From the second day of hospitalisation, laboratory findings showed a progressive reduction of inflammatory markers (table 1). Brugada pattern was no more detectable in daily ECGs: actually, an incomplete right bundle branch block was documented in ECG performed on day 2, while a normal sinus rhythm was present on day 3 (figure 1). A 24-hour Holter monitoring performed 48 hours after admission did not found abnormalities except for nocturnal bradycardia (minimum 44 bpm). Genetic sequencing studies for SCN5A mutations were obtained, not revealing abnormalities.