Novel Technique for Measurement of Fetal Right Myocardial Performance Index Using Dual Gate Pulsed-Wave Doppler.

OBJECTIVES: To evaluate the reproducibility of the fetal right myocardial performance index determined by simultaneous recording of inflow and outflow using a dual gate pulsed-wave Doppler (DD).

METHODS: This was a prospective study of 39 normal singleton fetuses. Two experienced operators each measured the right myocardial performance index in three ways, twice: (1) separate recording of the inflow and outflow using single-gate pulsed-wave Doppler (PD), (2) simultaneous recordings of the inflow and outflow using tissue Doppler (TD), and (3) simultaneous recordings of the inflow and outflow using DD. Intra- and interoperator reproducibility were assessed with intraclass correlation coefficients. The measurements from all three methods taken by the more experienced operator were compared using Bland-Altman plots and mean differences.

RESULTS: For both operators, intra-operator reproducibility was the highest when using DD, followed by PD, and TD. Interoperator agreement was the highest for PD measurements, followed by DD, and TD. The smallest mean difference was between the PD and DD measurements by the more experienced operator. There was a positive correlation between PD and DD values (r = 0.369, P < .001).

CONCLUSIONS: Dual gate pulsed-wave Doppler may be an effective alternative to the PD or TD methods, and can separately evaluate systolic and diastolic myocardial function.