Lack of correlation of two performance parameter – MPI and strain- in the normal fetal heart – a tissue doppler echocardiography (TDI) study

Objective: An explorative study on correlation of two parameter describing myocardial performance – myocardial performance index (MPI) and strain – in the normal fetal heart in the second trimester of pregnancy.

Materials and methods: In 20 fetuses without abnormalities in the second trimester screening between 19th and 24th week of gestation longitudinal four chamber view colour TDI cineloops of 3 cardiac cycles were recorded. Sample areas were in the subvalvulare plane, the middle segment and the apical part of the myocardium of free walls of both ventricles and the interventriculare septum. Thus allowing the simultaneous measurement of strain and myocardial velocities in different regions in the same heart cycle, thereby ICT, ejection phase and IRT could be measured to calculate MPI.

Results: In the basal sample areas correlation ranged form -0.35 (p=0.27) to 0.33 (p=0.32), in the middle segments form -0.17 (p=0.61) to 0.19 (p=0.53). Correlation of the two parameters was estimated for every sample area using the Spearman's method but no significant correlation was found.

Conclusion: There was no correlation at all sample areas between the two parameters describing myocardial performance in the longitudinal direction of myocardial motion in the fetal heart in the second trimester of pregnancy.