Background:
A global pandemic was declared in March 2020 due to a novel coronavirus identified as SARSCoV-2, which causes mild disease in children. A post-infectious inflammatory response to COVID-19 was described in children in April 2020 and is known as multisystem inflammatory syndrome in children (MIS-C). Pediatric patients may present with fever, gastrointestinal symptoms, rash, conjunctivitis, mucous membrane involvement, neurocognitive symptoms, respiratory symptoms, pharyngitis, myalgia, swollen extremities, and lymphadenopathy. Patients also have elevated acute phase reactants and inflammatory markers. Patients may have elevated cardiac markers, including troponin and B-natriuretic peptide as well as abnormal echocardiographic findings of myocardial dysfunction, coronary artery abnormalities, pericardial effusion, myocarditis, and mitral valve regurgitation. Rarely arrhythmias have been reported, but have included premature atrial and ventricular beats, QTc prolongation, ST/T wave abnormalities, non-sustained ventricular tachycardia, and first/second degree atrioventricular block. The finding of a left axis idioventricular relative bradycardic rhythm in the setting of severe hypotension is rather unique. This is a case report of a patient with profound hypotension and an inappropriate heart rate response, with a left bundle idioventricular bradycardia in the setting of multisystem inflammatory syndrome in children.
History:
A 13-year-old Hispanic male, presented to the emergency department with three days of fevers, listlessness, abdominal pain, vomiting, diarrhea, headache, and rash.
Physical exam:
Vitals: BP 63/34 mmHg, HR 90-97, 36.2°C, 96% SPO2 on room air, after several hours he was febrile to 39.4°C.
Gen: Toxic appearing, dehydrated
HEENT: Conjunctival injection, cracked lips, tacky mucous membrane
CV: HR 92, capillary refill 4-5 seconds
Resp: clear, no work of breathing
GI: No abdominal tenderness, no acute abdomen
Neuro: Listless
Skin: Mild pallor, erythematous macular rash over abdomen with additional lesions over bilateral lower legs
Laboratory, Diagnostic, and Procedures:
CBC: Hb/Hct: 13.2/39, Platelets: 194, WBC: 21.41x 10^3 - 68%Neutrophils, 22%Bands, 3%Lymphocytes
PT 15.8 sec, IR 1.3
CMP: Na 132, K 3.9, Cl 91, CO2 23, BUN 54, Cr 2.2, BG 109
AST 42, ALT 62
Albumin 2.7
CRP 30.5 mg/dL
ESR 57 mm/Hr
Ferritin 801 ng/mL, Fibrinogen 812 mg/dL
BNP 1154 pg/mL
Troponin I 0.65 ng/mL
Procalcitonin 9.3
D-dimer 1.71 ug/mL
Lactic acid 2.7 mmol/L
EKG showed Mobitz I AV block followed by accelerated idioventricular rhythm with left axis deviation followed by sinus tachycardia with fusion beat followed by normalization
Echocardiogram showed mildly dilated aortic valve annulus and root, normal coronary arteries, low normal ejection fraction, and small pericardial effusion
Rapid SARS-CoV-2 PCR negative
Blood and urine culture
SARS-CoV-2 antibodies: IgM negative, IgG positive, IgA positive
Final diagnosis:
The patient was diagnosed with multisystem inflammatory syndrome in children. The patient required an epinephrine drip to maintain normotensive blood pressures and ICU care. Electrolytes were replaced frequently. The patient was treated with 2 g/kg of intravenous immunoglobulin (IVIG) on hospital day one. Following IVIG the patient rapidly improved clinically and symptomatically. Labs normalized and the arrhythmia resolved. The patient was off epinephrine by hospital day three and discharged on hospital day four without further sequela.
Discussion:
This is a report of a unique case of idioventricular cardiac rhythm while in uncompensated shock with multisystem inflammatory syndrome in children. Patients presenting in shock typically have an exaggerated sinus response with sinus tachycardia. The fact that this patient presented with relative bradycardia for his degree of fever and hypotension is atypical. The suppression of the sinus node and the finding of an idioventricular rhythm with profound hypotension suggests that the inflammatory process seen in multisystem inflammatory syndrome in children can transiently affect the sinus node region leading to a paradoxical heart rate response. Thus, when caring for these patients, considering sinus node dysfunction in the setting of shock is crucial as this impacts clinical management, especially when the patient is hemodynamically unstable. Very close observation and early initiation of vasopressors, inotropes, or even pacing must be considered. Interestingly, the inflammatory process was rather quickly dampened following immunoglobulin administration and resolution of symptomatology occurred. Sinus node injury in the midst of an acute hypotensive COVID-19 induced multisystem inflammatory syndrome in children presentation has not been previously reported. Clinicians caring for children with multisystem inflammatory syndrome in children should be mindful of possible abnormalities in sinus node function that are disparate from the typical tachycardia response seen in pediatric shock.
