Bregel LV, Efremova OS, Kostik MM. Letter to the Editor: Coronavirus disease 2019, multisystem inflammatory syndrome, and children’s hearts: Finding answers with cardiac magnetic resonance imaging. World J Clin Pediatr 2026; 15(4): 122753 [DOI: 10.5409/wjcp.122753]
Corresponding Author of This Article
Mikhail M Kostik, MD, PhD, Head, Professor, Department of Hospital Pediatry, Saint Petersburg State Pediatric Medical University, Lytovskaya 2, Saint Petersburg 194100, Sankt-Peterburg, Russia. kost-mikhail@yandex.ru
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Pediatrics
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letter
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Bregel LV, Efremova OS, Kostik MM. Letter to the Editor: Coronavirus disease 2019, multisystem inflammatory syndrome, and children’s hearts: Finding answers with cardiac magnetic resonance imaging. World J Clin Pediatr 2026; 15(4): 122753 [DOI: 10.5409/wjcp.122753]
World J Clin Pediatr. Dec 9, 2026; 15(4): 122753 Published online Dec 9, 2026. doi: 10.5409/wjcp.122753
Letter to the Editor: Coronavirus disease 2019, multisystem inflammatory syndrome, and children’s hearts: Finding answers with cardiac magnetic resonance imaging
Liudmila V Bregel, Olesya S Efremova, Mikhail M Kostik
Liudmila V Bregel, Olesya S Efremova, Department of Pediatric Cardiology, Irkutsk Regional Children’s Clinical Hospital, Irkutsk 664022, Russia
Liudmila V Bregel, Olesya S Efremova, Department of Pediatry, Irkutsk State Medical Academy of Postgraduate Education, A Branch of the Russian Medical Academy of Continuous Professional Education, Irkutsk 664049, Russia
Mikhail M Kostik, Department of Hospital Pediatry, Saint Petersburg State Pediatric Medical University, Saint Petersburg 194100, Sankt-Peterburg, Russia
Author contributions: Bregel LV, Efremova OS, and Kostik MM contributed to this paper; Bregel LV and Kostik MM designed the overall concept and outline of the manuscript, contributed to the writing, editing of the manuscript, and review of the literature; Bregel LV and Efremova OS contributed to the discussion and design of the manuscript.
AI contribution statement: Portions of this manuscript were edited using AI tools solely for language refinement. The authors carefully reviewed and verified all AI-assisted outputs and take full responsibility for the scientific content of the manuscript.
Conflict-of-interest statement: The authors report having no relevant conflicts of interest for this manuscript
Corresponding author: Mikhail M Kostik, MD, PhD, Head, Professor, Department of Hospital Pediatry, Saint Petersburg State Pediatric Medical University, Lytovskaya 2, Saint Petersburg 194100, Sankt-Peterburg, Russia. kost-mikhail@yandex.ru
Received: April 27, 2026 Revised: May 30, 2026 Accepted: August 10, 2026 Published online: December 9, 2026 Processing time: 142 Days and 16.3 Hours
Abstract
The article refers to “Persistent long-term subclinical myocardial changes in multisystem inflammatory syndrome in children revealed by cardiac magnetic resonance and galectin-3” by OV et al published in the World Journal of Clinical Pediatrics, multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19) and its cardiovascular complications. MIS-C frequently causes cardiovascular complications, including coronary artery dilatation, low left ventricular (LV) ejection fraction, diastolic dysfunction, myocarditis, and pericardial effusion, decreases over time, usually resolving within 6-9 months after the disease onset. Echocardiographic evaluations reveal mild to moderate LV dysfunction, resolving within two weeks. Severe dysfunction normalizes after approximately 1.5 months. Global longitudinal strain proves valuable for detecting subclinical myocardial damage. Long-term effects based on cardiac magnetic resonance imaging (CMRI) data indicate the persistent myocardial edema and/or fibrosisupto12 months after the initialevent. Signs of interstitial fibrosis were found in 7.7% of patients during a one-year follow-up period. CMRI is an important additional method in the assessment of children who have experienced multisystem inflammatory syndrome in COVID-19, especially in patients with persistent symptoms or abnormal data from other cardiac findings.
Core Tip: Multisystem inflammatory syndrome in children related to coronavirus disease 2019 (COVID-19), concentrating on cardiovascular complications, including myocardial dysfunction, primarily due to myocarditis. While coronary artery dilation is usually moderate and resolves quickly, myocarditis can be severe but typically improves over time. Cardiovascular abnormalities such as dilated coronary arteries, reduced left ventricular ejection fraction, diastolic dysfunction, myocarditis, and pericardial effusions generally subside within 6 to 9 months. Global longitudinal strain is effective for detecting subtle myocardial damage. Long-term cardiac magnetic resonance imaging reveals persistent myocardial edema or fibrosis for up to a year, with interstitial fibrosis and could be recommended as the primary or follow-up imaging technique for COVID-19 patients.
