Prognostic significance of tissue Doppler imaging-derived myocardial performance index in pediatric patients with dilated cardiomyopathy

The Role of Multimodality Imaging in Pediatric Cardiomyopathies

Cardiomyopathies are a heterogeneous group of myocardial diseases representing the first cause of heart transplantation in children. Diagnosing and classifying the different phenotypes can be challenging, particularly in this age group, where cardiomyopathies are often overlooked until the onset of severe symptoms. Cardiovascular imaging is crucial in the diagnostic pathway, from screening to classification and follow-up assessment. Several imaging modalities have been proven to be helpful in this field, with echocardiography undoubtedly representing the first imaging approach due to its low cost, lack of radiation, and wide availability. However, particularly in this clinical context, echocardiography may not be able to differentiate from cardiomyopathies with similar phenotypes and is often complemented with cardiovascular magnetic resonance. The latter allows a radiation-free differentiation between different phenotypes with unique myocardial tissue characterization, thus identifying the presence and extent of myocardial fibrosis. Nuclear imaging and computed tomography have a complementary role, although they are less used in daily clinical practice due to the concern related to the use of radiation in pediatric patients. However, these modalities may have some advantages in evaluating children with cardiomyopathies. This paper aims to review the strengths and limitations of each imaging modality in evaluating pediatric patients with suspected or known cardiomyopathies.

Myocardial performance index increases at long-term follow-up in patients with mild to moderate COVID-19

Background

The long‐term cardiovascular effects of Coronavirus disease‐2019 (COVID‐19) are not yet well known. Myocardial performance index (MPI) is a non‐invasive, inexpensive and reproducible echocardiographic parameter that reflects systolic and diastolic cardiac functions. The aim of the study was to compare MPI with a healthy control group in patients with mild or moderate COVID‐19 infection who subsequently had unexplained cardiac symptoms.

Methods

The study included 200 patients aged 18–70 years who were diagnosed with COVID‐19 infection at least 2 months ago and defined cardiac symptoms in their follow‐up. Patients with mild or moderate symptoms, no history of hospitalization, and no other pathology that could explain cardiac symptoms were included in the study. As the control group, 182 healthy volunteers without COVID‐19 were evaluated. Echocardiographic examination was performed on the entire study group. Isovolumetric contraction time (IVCT), isovolumetric relaxation time (IVRT), and ejection time (ET) were measured by tissue Doppler imaging. MPI was calculated with the IVCT+IVRT/ET formula.

Results

The mean age of the study group was 44.24 ± 13.49 years. In the patient group the MPI was significantly higher (.50 ± .11 vs .46 ± .07, p < .001), IVRT was longer (69.67 ± 15.43 vs 65.94 ± 12.03 ms, p = . 008), and ET was shorter (271.09 ± 36.61 vs 271.09 ± 36.61 ms, p = .028). IVCT was similar between groups (63.87 ± 13.66 vs. 63.21 ± 10.77 ms, p = .66). Mitral E and mitral A wave, E’, A’, and E/A were similar in both groups.

Conclusions

Our study showed that conventional diastolic function parameters were not affected in patients who survived COVID‐19 with mild symptoms but had symptoms in the long term. However, MPI measurements showed left ventricular dysfunction. To our knowledge, this is the first echocardiographic follow‐up study to evaluate left ventricular systolic and diastolic functions with MPI in COVID‐19 patients. We think that when cardiac involvement assessment is required in patients who have survived COVID‐19, MPI should be measured alongside other echocardiographic measurements.