Normal values of MAPSE and TAPSE in the paediatric population established by cardiovascular magnetic resonance


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distance between the cutting edge of the tricuspid annulus with right ventricular (RV) free wall captured at end-diastole and at end-systole ( Fig. 1).
Simple linear regression was used to establish the association between MAPSE or TAPSE with age, gender, body surface area (BSA), heart rate, ventricular end-diastolic volume index (LVEDVi, RVEDVi) and ejection fraction (LVEF, RVEF). Multiple linear regression was than performed including variables that were significant in the univariate analysis. Intra-observer and inter-observer variability was determined in 25 patients measured by two independent observers, using intraclass correlation coefficient (ICC). All tests were two tailed and significance was set at 0.05.
Ejection fraction (EF) is a widely recognised index of global systolic function in guidelines and clinical practice. However, EF alone has low sensitivity in detecting early contractile impairment with limitations in certain conditions [1].
It is widely considered that the more longitudinally oriented subendocardial fibres provide a significant contribution to normal cardiac function. Strain imaging enables quantification of longitudinal contractile function and has been proven to improve the identification of subclinical LV systolic dysfunction in patients with heart failure with preserved EF (HFpEF). However, compared to echocardiography, CMR-derived longitudinal strain analysis is time consuming and limited by a lack of validation and general availability.
Also MAPSE and TAPSE have been shown to be more sensitive than EF in certain settings including HFpEF. TAPSE showed high negative predictive power in detecting RV dysfunction and has been shown to be an independent predictor of cardiovascular death in the general population, especially in individuals with normal EF [2]. As with echocardiography, CMR-derived TAPSE and MAPSE can be readily available and may serve as additional parameters for the evaluation of LV and RV global function. Because the amount of annular displacement is likely to be affected by heart size and considering growth changes in the paediatric population, it is reasonable not to use a single value but rather reference values to age and/or BSA to best interpret the results. In our study, MAPSE and TAPSE showed only a weak positive correlation with age and ventricular volumes. This weak correlation may be due to the distribution of our study population, as children < 10 years of age are less likely to be referred for a CMR scan than adolescents (who make up almost half of our study population), due to the need for sedation.
Author contributions Each author has contributed substantially to the research, preparation and production of the manuscript and approves its submission to The International Journal of Cardiovascular Imaging. Each author agrees to be accountable for all aspects of the work.
Funding None.
Data availability Authors have full control of all primary data and agree to allow the journal to review their data if requested.
Code availability Not applicable.

Conflict of interest
The authors declare that they have no conflict of interest to disclose.

Ethical approval
The study has have been approved by the institutional ethics committee and has been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.
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