To determine whether Doppler color flow mapping could be used to quantify changing levels of regurgitant flow and define the technical variables that influence the size of color flow images of regurgitant jets, nine stable hemodynamic states of mitral insufficiency were studied in four open chest sheep with regurgitant orifices of known size. The magnitude of mitral regurgitation was altered by phenylephrine infusion. Several technical variables, including the type of color flow instrument (Irex Aloka 880 versus Toshiba SSH65A), transducer frequency, pulse repetition frequency and gain level, were studied. Significant increases in the color flow area, but not in color jet width measurements, were seen after phenylephrine infusion for each regurgitant orifice. For matched levels of mitral regurgitation, an increase in gain resulted in a 125% increase in color flow area. An increase in the pulse repetition and transducer frequencies resulted in a 36% reduction and a 28% increase in color flow area, respectively. Jet area for matched regurgitant volumes was larger on the Toshiba compared with the Aloka instrument (5.2 +/- 3.1 versus 3.2 +/- 1.2 cm2, p less than 0.05). Color flow imaging of mitral regurgitant jets is dependent on various technical factors and the magnitude of regurgitation. Once these are standardized for a given patient, the measurement of color flow jet area may provide a means of making serial estimates of the severity of mitral insufficiency.
We describe the echocardiographic findings in a large reptile-the carpet python. If ontogeny recapitulates phylogeny, the study of reptilian hearts may provide insights into human cardiac development. In addition, the reptilian heart has unique structural and physiological adaptations that may broaden our perspective on evolutionary cardiac adaptation.
ABSTRACT. The concentration of plasma atrial natriuretic factor (ANF) and the mechanism for its secretion were investigated in 17 preterm infants with respiratory distress. Their mean gestational age was 29 wk and wt 1250 g. The infants were followed during the first week of life by sequential Doppler ultrasound studies. Ductal openness versus closure and amount of ductal flow were correlated with plasma ANF concentrations. In a subset of 10 infants, sequential Doppler color flow mapping was used to quantify the ductal flow. During the first 72 h, plasma ANF was high, 361 pg/mL; it decreased to 96 pg/mL by the end of the 1st wk. (4, 5). In neonates with RDS (6) plasma concentration of ANF is increased compared to normal newborns. In these patients the peak plasma ANF concentration coincides with the diuretic phase found between 18 to 43 h of age (7).To clarify the association of ANF secretion and hemodynamic changes in preterm infants with RDS, we determined the Qp/Qs ratio and ductal closure by CFM with a method we developed previously (8). The focus of this study was the effect of ductal flow on plasma ANF concentration in preterm infants with RDS.
MATERIALS AND METHODSSeventeen preterm infants (26-33 wk gestation) with birth wt of 0.66 to 1.95 kg (mean 1.25 kg) developed clinical signs and radiographic features consistent with RDS. Nine infants were delivered by caesarean section, and Apgar scores ranged from 3 to 8 at 1 min (mean 6) and from 6 to 9 at 5 min (mean 8). In 15 infants, analysis of amniotic fluid obtained within 24 h before birth revealed lecithin/sphingomyelin ratios less than 2.0 with absence of phosphatidylglycerol, and in two remaining infants tracheal aspirates obtained at birth contained no phosphatidylglycerol. These findings and the clinical course were consistent with severe RDS. This was further substantiated by calculating the arteriolar/alveolar oxygen tension ratio (9) at 6 h of age (0.17 5 0.08: mean + SD), which confirmed the disturbance in gas ANF, atrial natriuretic factor exchange and the requirement for supplemental oxygen and CFM, color flow mapping mechanical ventilation. Infants included in this study had no LA/Ao ratio, left atrial to aortic root diameter evidence of chorioamnionitis, congenital infection, or major PDA, patent ductus arteriosus malformations.Qp/Qs, pulmonic to systemic blood flow ratio Blood samples of 0.5 mL were drawn through umbilical artery catheters into ice-cold EDTA-containing tubes that were rapidly RDS, respiratory distress syndrome centrifuged at 300 x n. Plasma was sevarated for immediate freezingand stored at -3 0 "~ for up to 3 mo before ANF analysis. From each patient during the 1st wk of life, one to four samples were taken within 3 h of a CFM study. RIA was camed out as ANF is a secreted from the atria of the heart (1). In term previously described (10). Sensitivity of the method is 5 pg/mL. newborns plasma concentration of ANF is increased during the The intra-and interassay coefficients of variation are 10.6 and first 2 to 4 d of life (2,...
Anomalous origin of the left coronary artery from the pulmonary artery is a rare but important cause of congestive heart failure in infancy and of sudden death at all ages. Diagnosis is often missed when based solely on physical examination and noninvasive methods. A 4 year old patient is presented in whom mitral regurgitation was noted by a referring physician and an anomalous left coronary artery was found by Doppler color flow mapping upon referral and verified at cardiac catheterization. Doppler color flow mapping was also used intraoperatively using a gas-sterilized transducer to further clarify the hemodynamics and assess the surgical result. After creation of an intrapulmonary artery tunnel from the ostium of the left coronary artery to the aorta, anterograde coronary artery flow and absence of a residual left to right pulmonary artery shunt were verified during surgery by Doppler flow mapping. Postoperatively, residual mitral regurgitation and patency of the left coronary artery graft have been followed up serially by Doppler flow mapping. Therefore, Doppler color flow mapping is useful in the diagnosis and intraoperative and postoperative management of this important and potentially life-threatening abnormality.
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