Fetal myocardial performance index in the 3rd trimester: Feasibility and reproducibility of spectral vs tissue Doppler

To compare completion rates and reproducibility of spectral and tissue Doppler myocardial performance index (MPI) in an unselected high risk third trimester population. This was a prospective cross-sectional study of high risk third trimester pregnancies >28+0. A single fetal echocardiogram, including spectral and tissue Doppler MPI of the left ventricle (LV) and right ventricles (RV) was attempted. McNemar's test was used to evaluate completion rates, and intraclass coefficients (ICC) were calculated to assess intra and inter observer variability. Seventy-nine pregnancies were evaluated. LV tissue Doppler MPI was completed more frequently than LV spectral Doppler MPI (63/79, 79.7% vs 45/79, 57%), p<0.01. RV tissue Doppler MPI was completed more frequently that RV spectral Doppler MPI (68/79, 86% vs 42/79, 53.2%), p<0.01. Sub analysis for the obese population (n=50) showed LV tissue Doppler MPI was completed more frequently than LV spectral Doppler MPI (37/50, 74% vs 26/50, 52%), p<0.01. RV tissue Doppler MPI was completed more frequently than RV spectral Doppler MPI (40/50, 80% vs 25/50, 50%), p<0.01. ICC for all modalities ranged 0.73-0.93, except for LV spectral Doppler interobserver variability which was 0.22. Tissue Doppler showed a statistically significant higher completion rate than spectral Doppler in this population with strong reproducibility. This trend holds for the obese population. Tissue Doppler should be considered for use in the patient requiring fetal cardiac function evaluation in the third trimester.View Large Image Figure ViewerDownload Hi-res image Download (PPT)