Quantitative, Noninvasive Assessment of Patent Ductus Arteriosus Shunt Flow by Measuring Proximal Isovelocity Surface Area on Color Doppler Mapping in Very Low-Birth-Weight Infants.

Background Our goal was to evaluate the hemodynamic status of very low-birth-weight infants (VLBWIs) with patent ductus arteriosus (PDA) by measuring the vena contracta width (VCW) and effective shunt orifice area (ESOA) using the proximal isovelocity surface area (PISA) on color Doppler imaging. Method and Results In this study, 34 VLBWIs with PDA (median weight: 949 g) were studied. We measured VCW and ESOA using the PISA on echocardiography. PDA-VCW was measured at the narrowest PDA flow region. ESOA determined using PISA (PDA-ESOA) was defined as the hemispheric area of laminar flow with aliased velocities on color Doppler flow imaging: PDA-ESOA = 2π (PDA radius) 2 × aligning velocity/PDA velocity. Of the 34 VLBWIs, 26 received indomethacin (IND) for symptomatic PDA. Comparing echocardiographic parameters between infants who did versus did not receive IND, significant differences were seen in the left atrial-to-aortic root ratio (LA/AO), PDA-VCW, and PDA-ESOA. Receiver operating characteristic curve analysis to differentiate between IND usage status produced statistically significant results for PDA-VCW (area under the curve [AUC] = 0.880), PDA-ESOA (AUC = 0.813), and LA/AO (AUC = 0.769). Conclusion PDA-VCW and PDA-ESOA may allow noninvasive assessment of PDA severity, and are useful when determining the timing of clinical decision making for IND administration.

Hemodynamic assessment in a child with renovascular hypertension using time-resolved three-dimensional cine phase-contrast MRI.

Renovascular hypertension (RVH) is an important cause of hypertension in children. It is essential to assess the hemodynamics of RVH lesions in detail. We herein report the case of a 9-year-old female with RVH caused by left renal artery stenosis in which the hemodynamics of the lesions were assessed with time-resolved three-dimensional cine phase-contrast MRI (3D cine PC MRI) with a vastly undersampled 3D radial projection imaging trajectory before and after percutaneous transluminal renal angioplasty (PTRA). The utility of 3D cine PC MRA for diagnosing RVH and evaluating the renal blood flow pre- and post-PTRA is presented.

Quantitative, noninvasive assessment of patent ductus arteriosus shunt flow by measuring proximal isovelocity surface area on color Doppler imaging.

BACKGROUND: We evaluated the hemodynamic status of patent ductus arteriosus (PDA) by measuring vena contracta width (VCW) and effective shunt orifice area (ESOA) using proximal isovelocity surface area (PISA) on color Doppler imaging. METHODS AND RESULTS: Study subjects were 21 patients with PDA (mean age, 3.6 years). We measured VCW (mm/m(2)) and ESOA (cm(2)) by the PISA method using echocardiography. Color images were obtained from parasternal long-axis views. VCW (mm/m(2)) was measured at the narrowest region of PDA flow. ESOA by PISA (PDA-ESOA) was defined on color Doppler flow imaging as a hemispheric area of laminar flow with aliased velocities [PDA-ESOA (cm(2))=2π[PDA radius (cm)]^2×aligning velocity (cm/s)/PDA peak velocity (cm/s)]. Upon examining the relationships with catheterization parameters by univariate analysis, VCW correlated with diastolic blood pressure (DBP), % left ventricular end-diastolic volume (%LVEDV), pulmonary blood flow index, pulmonary blood flow/systemic blood flow ratio (Qp/Qs), left-right (LR) shunt ratio, left atrial to aortic root ratio (LA/AO), chest-thoracic ratio and N-terminal pro-brain natriuretic peptide (NTproBNP); and PDA-ESOA correlated with DBP, Qp/Qs, average pulmonary artery pressure, pulmonary/systemic pressure ratio, %LVEDV, LR shunt ratio, LA/AO and NTproBNP. When stepwise multiple linear regression analysis was performed with the correlations that were significant on univariate analysis, significant correlations with Qp/Qs were noted (VCW; R(2)=0.836, ß=0.914, P<0.001, PDA-ESOA; R(2)=0.621, ß=0.788, P<0.001). CONCLUSIONS: Measurement of VCW and PDA-ESOA by the PISA method can noninvasively evaluate the hemodynamic status of PDA.

Fetal myocardial tissue Doppler indices before birth physiologically change in proportion to body size adjusted for gestational age in low-risk term pregnancies.

BACKGROUND: Few studies have investigated the relationship between myocardial tissue Doppler parameters and fetal size adjusted for gestational age and its trend has been controversial. AIMS: To investigate fetal cardiac function before birth using tissue Doppler imaging (TDI: indicated by the prime symbol (')) in low-risk term pregnancies by comparing the TDI parameters with gestational age-specific birth weight percentiles and z scores. STUDY DESIGN AND MEASUREMENTS: Interventricular septum, left and right ventricular myocardial peak early diastolic (E'), late diastolic (A') and systolic (S') velocities, E'/A' ratios, myocardial performance index (MPI') and umbilical artery pulsatility index were measured within three days before birth in 76 low-risk term pregnancies, including appropriate for gestational age (AGA, n=50), small for gestational age (SGA, n=10), and large for gestational age (LGA, n=16) subjects. RESULTS: Myocardial peak velocities showed higher in the LGA and lower in the SGA compared with the AGA group, and All S' positively correlated with birth weight (r=0.51-0.57). All z scores of S' demonstrated a positive correlation with birth weight z score (Spearman r=0.45-0.53). MPI' was significantly higher in the SGA and lower in the LGA compared with the AGA group. All MPI' negatively correlated with birth weight (r=-0.55 to -0.65). All z scores of MPI' showed a negative correlation with birth weight z score (Spearman r=-0.40 to -0.56). CONCLUSIONS: Fetal myocardial peak velocities and MPI' physiologically changed in proportion to body size adjusted for gestational age in low-risk term pregnancies.