Fetal left ventricular myocardial performance index: Defining normal values for Indian population and a review of literature

Abstract

Objective:The aim of this study was to determine normal values for fetal left ventricular (LV)-myocardial performance index (MPI) in Indian population and to assess its relation to advancing gestation and fetal heart rate (FHR).Materials and Methods:Two hundred pregnant women without any pregnancy-related complications and whose fetuses were shown to have structurally normal hearts were enrolled in this study. Doppler waveform involving simultaneous display of mitral inflow and LV outflow was obtained in all. Various intervals including isovolumetric contraction time (IVCT), isovolumetric relaxation time (IVRT), and ejection time (ET) were measured and then the MPI was calculated using the formula IVCT + IVRT/ET. Also the correlation between MPI and gestation age and FHR was assessed. We also reviewed the literature on the use of MPI for the assessment of fetal LV function.Results:The normal MPI in second and third trimester fetuses of Indian population was 0.42 ± 0.03. The mean IVCT was 33 ± 4 milliseconds (ms), mean IVRT was 39 ± 5 ms, and mean ET was 169 ± 9 ms. The mean heart rate was 148 ± 8 bpm and the mean PR interval was 111 ± 10 ms. There was no significant association of LV-MPI with either FHR or advancing gestation.Conclusion:MPI is a useful parameter for the assessment global cardiac function. MPI has the advantage of not being affected by FHR, ventricular size, and geometry or image quality. The review of literature shows its significant importance in monitoring complicated pregnancies.

Conventional Doppler myocardial performance index, tricuspid and mitral annular plane systolic excursions in the assessment of fetal heart functions

“…Some studies have reported that it increases in advanced weeks of gestation while some other studies have argued that there is no such correlation and there is even a negative correlation. [12,16,17] In our study, we did not observe a significant increase in advanced weeks of gestation. When calculating Tei index, some authors measured ventricle entrance (mitral and tricuspid valves) and exit (aortic and pulmonary) pulsed Doppler records separately while some authors only measured time intervals that they obtained from a single Doppler record placed on an appropriate position.…”

Assessment of fetal modified myocardial performance index in early‐onset and late‐onset fetal growth restriction

“…It is a noninvasive Doppler‐derived indicator that evaluates global myocardial function . MPI has been proved to be a reliable parameter, not being affected by fetal cardiac ventricular size, fetal heart rate, and geometry . Some studies have demonstrated that FGR cases were associated with prenatal adverse cardiac remodeling .…”

“…6 MPI has been proved to be a reliable parameter, not being affected by fetal cardiac ventricular size, fetal heart rate, and geometry. 7,8 Some studies have demonstrated that FGR cases were associated with prenatal adverse cardiac remodeling. 9,10 The aim of this study was to investigate the changes of MPI in early-and late-onset FGR cases with different Doppler manifestations and its association with adverse perinatal outcome, to further confirm the clinical value of MPI in detecting and monitoring FGR.…”

Evaluation of Hemodynamic Changes in Fetuses With Isolated Mild‐to‐Moderate Ventriculomegaly by Transabdominal Ultrasound

“…Nevertheless, to the best of our knowledge, the assessment of fetal cardiac function is still evolving. The MPI has been proven to be independent of gestational age and the fetal heart rate, and the MPI can be used for the initial evaluation of global cardiac function in healthy fetuses and fetuses with congenital malformations . The IRT is the most important component of the MPI, and its derangement in the MPI indicates the earliest change in cardiac function impairment in diseased states .…”

“…The MPI has been proven to be independent of gestational age and the fetal heart rate, and the MPI can be used for the initial evaluation of global cardiac function in healthy fetuses and fetuses with congenital malformations. 15 The IRT is the most important component of the MPI, and its derangement in the MPI indicates the earliest change in cardiac function impairment in diseased states. 16 We found that fetuses with isolated mild-tomoderate VM before 32 weeks' gestation had not only a significantly higher Mod-MPI but also a longer IRT than the control group, whereas fetuses with isolated mild-to-moderate VM after 32 weeks' gestation only had a significantly longer IRT, with no significant difference in the Mod-MPI.…”