The Fetal Modified Myocardial Performance Index: Is Automation the Future?

Abstract

The fetal modified myocardial performance index (Mod-MPI) is a noninvasive, pulsed-wave Doppler-derived measure of global myocardial function. This review assesses the progress in technical refinements of its measurement and the potential for automation to be the crucial next step. The Mod-MPI is a ratio of isovolumetric to ejection time cardiac time intervals, and the potential for the left ventricular Mod-MPI as a tool to clinically assess fetal cardiac function is well-established. However, there are wide variations in published reference ranges, as (1) a standardised method of selecting cardiac time intervals used in Mod-MPI calculation has not been established; (2) cardiac time interval measurement currently requires manual, inherently subjective placement of callipers on Doppler ultrasound waveforms; and (3) ultrasound machine settings and ultrasound system type have been found to affect Mod-MPI measurement. Collectively these factors create potential for significant inter- and intraobserver measurement variability. Automated measurement of the Mod-MPI may be the next key development which propels the Mod-MPI into routine clinical use. A novel automated system of Mod-MPI measurement is briefly presented and its implications for the future of the Mod-MPI in fetal cardiology are discussed.

Assessment of fetal myocardial performance index in women with pregestational and gestational diabetes mellitus

“…A prospective cohort design with larger numbers of participants rather than a case control type, including the examination of MPI by neonatal echocardiography, could reveal more valuable data to support our objectives. Moreover, evaluation of intra‐observer and inter‐observer reliabilities for MPI in randomized trials with single‐blind design and novel auto‐techniques would produce more reliable results . Finally, long‐term postnatal follow‐up of the cardiac status of a baby with a diabetic mother would more clearly show the utility of prenatal MPI evaluation.…”

Fetal Pulsed-Wave Doppler Atrioventricular Activity Detection by Envelope Extraction and Processing

“…The Atrioventricular Conduction time can be computed, in order to evaluate a possible atrioventricular block [6]. An important index, such as the Fetal Modified Myocardial Performance Index, is a ratio of isovolumetric to ejection time cardiac time intervals [7], and can be obtained automatically. Currently, these parameters are being evaluated.…”

Automated analysis of fetal cardiac function using color tissue Doppler imaging

“…The definition of the pre‐ejection phase with the manual method was also difficult sometimes, especially in the RV wall, and it is likely that a certain degree of subjectivity in the manual analysis will have influenced our measurements. This problem of subjectivity in the manual selection of time points has also been discussed with respect to assessment of the MPI. The subjectivity in measurement could be eliminated with an automated procedure.…”