Fetal left modified myocardial performance index measured by the Auto Mod-MPI system: development of reference values and application to recipients of twin-to-twin transfusion syndrome

Abstract

Normal reference values for left Mod-MPI were established using the Auto Mod-MPI system, and these might be useful for assessing cardiac function in TTTS. © 2016 John Wiley & Sons, Ltd.

Measurement of cardiac function by cardiac time intervals, applicability in normal pregnancy and twin-to-twin transfusion syndrome

“…Another difficulty in MPI measurements is the caliper placement in the Doppler waveforms to calculate the time intervals. This seems to be resolved with the development of automated MPI systems which removes the subjectivity of manual caliper placement, but authors acknowledge that ultrasound image acquisition remains a potential source of variability, even for highly trained operators [23,24]. Contrary, the cTDI recordings described in this study are easy to obtain because only a recording of the four-chamber view is needed.…”

“…It is, however, well accepted that reference charts of healthy singletons are compared to complicated monochorionic twins. In the previous studies in the field of fetal cardiology, speckle tracking-derived fetal cardiac function and modified MPI measurements in recipient twins were compared to normal singleton fetuses [24,34,35]. Uncomplicated (monochorionic) twins are generally not used as a control group, since twin pregnancies cannot be considered normal because of their complexity and high risk of complications.…”

Time Interval Measurements of the Ductus Venosus During the Early Second Trimester of Pregnancy: Reference Ranges and Clinical Application

“…Contrary to the donors, the recipients had longer total systolic times, resulting from an increased cardiac preload. Lee et al determined the myocardial performance index of twin‐twin transfusion syndrome recipients and found that both the isovolumic contraction time and isovolumic relaxation time increased compared with the normal reference values, supporting our results that the early systolic and diastolic times of the ductus venosus decreased. Comparing twin‐twin transfusion syndrome recipients with donors, Bensouda et al found that the recipients had a significantly decreased early diastolic time and total ventricular filling time (corresponding to the diastolic acceleration time and diastolic time, respectively), which is what we also found.…”

“…11 The significant elevation of the systolic time in the ductus venosus is supported by evidence that the ventricular volume and cardiac output of the fetal heart increase with advancing gestation. 15,16 For the time frame analysis of the myocardial performance index, a longer ejection time during the early second trimester of pregnancy 17,18 can explain the significantly increased systolic acceleration time and total systolic time. In contrast to the diastolic deceleration time, atrial systole was significantly decreased.…”

Automation of the Fetal Right Myocardial Performance Index to Optimise Repeatability

“…Our automation system utilises the peak of the valve click based on previous studies, which suggest a higher reproducibility with this position [20,28]. Lee et al [37] have also developed a left MPI reference range based on their automated algorithm and investi- Values displayed as intraclass correlation coefficients (95% confidence intervals). Observer 1 is inexperienced, and observer 2 is experienced.…”