Multisystem Inflammatory Syndrome in Children (MIS-C) is a known severe condition affecting children previously exposed to SARS-CoV-2. The aim of our study was to describe the early cardiac abnormalities in patients with MIS-C, evaluated by speckle tracking echocardiography (STE) and cardiac MRI (CMR). Clinical, laboratory and microbiological data were measured for all patients. All children underwent standard transthoracic echocardiography, STE with analysis of left ventricle global longitudinal strain (GLS). Seventeen (75%) of the children were evaluated with CMR. Twenty-three patients (13M, 10F) were recruited, mean age was 8.1 ± 4 years. Cardiovascular symptoms were present in 10 (43.5%). Nine children (39.1%) shared Kawasaki Disease-like symptoms. Four patients (17.4%) needed ICU admission. In-hospital survival was 100%. TnI was elevated in 15 (65.2%) and BNP in 20 (86.9%) patients. The median time to STE evaluation was 8 days and to CMR was 18 days after fever onset. Mean LVEF was 59 ± 10%. Coronary dilation was observed in six (26.1%) patients. STE showed a reduced mean LVGLS (−17 ± 4.3%). LGE with a non-ischemic pattern was evident in six out of seventeen patients (35.2%). The elevation of myocardial necrosis markers, the reduction of LVGLS and the presence of LGE on CMR in about a quarter of MIS-C patients supports the hypothesis of a post-viral immune-mediated myocarditis-like pathogenesis.

Aims Multisystem inflammatory syndrome in children (MIS-C) with cardiovascular manifestations are frequent. However, there is lacking evidence regarding cardiological follow-up of this cohort of patients. The aim of our study was to describe the early and mid-term cardiac abnormalities assessed by standard and speckle-tracking echocardiography (STE), and cardiac MRI (CMR). Methods and results We enrolled 32 patients (21 male, 11 female), mean age 8.25 ± 4years, with diagnosis of MIS-C. During admission, all children underwent TTE, STE with analysis of left ventricle global longitudinal strain (GLS) and CMR. Patients underwent cardiological evaluation at 2 (T1) and 6 months (T2) after discharge. Cardiac MRI was repeated at 6 months after discharge. Mean left ventricular ejection fraction (LVEF) at baseline was 58.8 ± 10% with 10 patients (31%) below 55%. Speckle-tracking echocardiography showed reduced mean LV GLS (−17.4 ± 4%). On CMR, late gadolinium enhancement (LGE) with non-ischaemic pattern was evident in 8 of 23 patients (35%). Follow-up data showed rapid improvement of LVEF at T1 (62.5 ± 7.5 vs. 58.8 ± 10.6%, P-value 0.044) with only three patients (10%) below ≤ 55% at T1. Left ventricular (LV) GLS remained impaired at T1 (−17.2 ± 2.7 vs.−17.4 ± 4, P-value 0.71) and significantly improved at T2 (−19 ± 2.6% vs. −17.4 ± 4%, P-value 0.009). LV GLS was impaired (>−18%) in 53% of patients at baseline and T1, whereas only 13% showed persistent LV GLS reduction at T2. Follow-up CMR showed LGE persistence in 33.4% of cases. Conclusion Early cardiac involvement significantly improves during follow-up of MIS-C patients. However, subclinical myocardial dysfunction seems to be still detectable after 6 months of follow-up in a not negligible proportion of them.

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Background: Although most children may experience mild to moderate symptoms and do not require hospitalization, there are little data on cardiac involvement in COVID-19. However, cardiac involvement is accurately demonstrated in children with MISC. The objective of this study was to evaluate cardiac mechanics in previously healthy children who recovered from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in a long-term follow-up by means of two-dimensional speckle-tracking echocardiography (STE). Methods: We analyzed a cohort of 157 paediatric patients, mean age 7.7 ± 4.5 years (age range 0.3–18 years), who had a laboratory-confirmed diagnosis of SARS-CoV-2 infection and were asymptomatic or mildly symptomatic for COVID-19. Patients underwent a standard transthoracic echocardiogram and STE at an average time of 148 ± 68 days after diagnosis and were divided in three follow-up groups (<180 days, 180–240 days, >240 days). Patients were compared with 107 (41 females—38%) age- and BSA-comparable healthy controls (CTRL). Results: Left ventricular (LV) global longitudinal strain (post-COVID-19: −20.5 ± 2.9 %; CTRL: −21.8 ± 1.7 %; p < 0.001) was significantly reduced in cases compared with CTRLs. No significant differences were seen among the three follow-up groups (p = NS). Moreover, regional longitudinal strain was significantly reduced in LV apical-wall segments of children with disease onset during the second wave of the COVID-19 pandemic compared to the first wave (second wave: −20.2 ± 2.6%; first wave: −21.2 ± 3.4 %; p = 0.048). Finally, peak left atrial systolic strain was within the normal range in the post-COVID-19 group with no significant differences compared to CTRLs. Conclusions: Our study demonstrated for the first time the persistence of LV myocardial deformation abnormalities in previously healthy children with an asymptomatic or mildly symptomatic (WHO stages 0 or 1) COVID-19 course after an average follow-up of 148 ± 68 days. A more significant involvement was found in children affected during the second wave. These findings imply that subclinical LV dysfunction may also be a typical characteristic of COVID-19 infection in children and are concerning given the predictive value of LV longitudinal strain in the general population.