Alterations in segmentary branch pulmonary artery blood flow velocimetry in fetuses of diabetic mothers.

OBJECTIVE: To evaluate pulmonary blood flow in fetuses of diabetic mothers by measuring changes in fetal segmentary pulmonary artery blood flow velocimetry throughout pregnancy. METHODS: Thirty-eight women with pregestational diabetes between weeks 18 and 38 were compared with 99 women with singleton low-risk gestations as controls. Flow velocity waveforms at the proximal middle and distal segments of the right pulmonary artery were obtained with power and color Doppler sonography in all fetuses. The pulsatility index of each segment was compared between the 2 groups. The mean value and 95% confidence interval for each segment were determined in correlation with gestational age for both groups. RESULTS: The highest mean pulsatility indices were obtained in the proximal segment of the pulmonary artery and were 2.25 in the diabetes group and 2.36 in controls. The mean pulsatility indices were significantly decreased in the middle and distal segments to 1.59 and 1.10 in the diabetes group and to 1.57 and 1.02 in controls (P < .05). There were no significant differences in pulsatility indices measured at the proximal and middle segments between the study and control groups. However, the mean pulsatility index +/- SD measured at the distal segment in the diabetic group was 9% higher than in controls (1.10 +/- 0.13 versus 1.02 +/- 0.12; P = .01). The mean pulsatility index (in the study and control groups) in each arterial segment did not change significantly throughout gestation (P > .1). CONCLUSIONS:. In human fetuses throughout gestation, the pulmonary circulation maintains stable vascular resistance in both diabetic and normal pregnancies. However, in all gestations, the pulsatility index in each segment of the pulmonary artery is unique and reflects the proximity to the heart and the impedance at each location. The significantly higher pulsatility index in the diabetes group might be related to alterations in the microcirculation of diabetic patients.     

Longitudinal survey of blood flow at three different locations in the middle cerebral artery in normal fetuses.

OBJECTIVES: To assess vascular impedance at three different locations in the middle cerebral artery (MCA) in normal fetuses throughout gestation. MATERIALS AND METHODS: Uncomplicated singleton pregnancies at 15-40 weeks' gestation in which Doppler surveys of both MCAs could be obtained were recruited. The pulsatility index (PI) and resistance index (RI) of the proximal, mid and distal sites of both MCAs were measured. The five gestation periods at which the Doppler surveys were performed were (i) 15-19 completed weeks; (ii) 20-24 completed weeks; (iii) 25-29 completed weeks; (iv) 30-34 completed weeks; (v) 35-39 completed weeks. RESULTS: A total of 42 fetuses were recruited. The average PI/RI values of the proximal, mid and distal MCA were 1.61/0.82, 1.77/0.82, and 1.84/0.84, respectively. The PI value of the proximal MCA was lower than that of the mid and distal MCA. The PI values of the mid and distal MCA showed no difference. The RI value of the MCA from the three locations also showed no difference. The PI/RI values of MCA for each gestational phase were: (i) 1.81/0.87; (ii) 1.79/0.86; (iii) 1.78/0.86; (iv) 1.70/0.81; (v) 1.62/0.77, respectively. Decreased PI/RI values were observed after 30 weeks' gestation. CONCLUSIONS: The PI values of the proximal MCA are lower than those of the mid and distal MCA. A marked decrease in PI/RI values was observed after 30 weeks' gestation.     

The effects of maternal indomethacin therapy on human fetal branch pulmonary arterial vascular impedance.

OBJECTIVE: To examine whether maternal indomethacin therapy affects human fetal pulmonary arterial vascular impedance without constriction of the ductus arteriosus and to determine the changes in the pulmonary arterial vascular impedance in the presence of ductal constriction. STUDY DESIGN: In this cross-sectional study, 52 normal fetuses without maternal medication (control group), 33 fetuses without ductal constriction (Study group I) and 11 fetuses with ductal constriction (Study group II) during maternal indomethacin therapy between 24 and 34 weeks of gestation were examined by Doppler echo-cardiography. Blood velocity waveforms across the proximal right or left pulmonary artery were obtained and the pulsatility index (PI) of the proximal pulmonary arteries was calculated. RESULTS: In the control group, the proximal pulmonary artery PI was higher (p < 0.0001) at 24-25 weeks (n = 7) (3.73 +/- 0.33; mean +/- SD) than at 33-34 week of gestation (n = 11) (2.98 +/- 0.27). The PI was constantly greater (p < 0.005) in Study group I than in the control group. However, in this group the mean average weekly decrease in the PI of the proximal pulmonary arteries was similar to that in the control group. After 26 weeks of gestation, the PI values in Study group II were significantly higher than in the control group (27 weeks: 4.12 vs. 3.34 (p < 0.005); 30 weeks: 4.48 vs. 3.14 (p < 0.0001); 34 weeks: 4.96 vs. 3.00 (p < 0.0001), respectively). CONCLUSIONS: Human fetal pulmonary arterial vascular impedance is increased by maternal indomethacin therapy even without ductal constriction. In the presence of ductal constriction, the magnitude of the increase in the vascular impedance is related to the gestational age.     

正常成人上肢动脉彩色多普勒超声测量

目的　应用彩色多普勒超声检查和测量正常上肢动脉 ,以得出上肢动脉的超声正常值。方法　15 3名健康志愿者 3 0 6条上肢动脉 ,每条上肢分 7个节段。测量解剖学和血流动力学参数。结果　获得上肢动脉各节段各参数超声正常值 ,发现上肢动脉从近心至远心段 ,内径减少 ,管壁变薄 ,收缩期峰值流速、收缩期加速度、搏动指数值下降 (P <0 .0 5 ) ;上肢动脉各节段均可表现多种流速曲线形态 ,近心段以双向三峰所占比例大(67%锁骨下动脉段双向三峰 ) ,腋动脉以远段反向峰渐不明显 (4 5 .2 %肱动脉段单向双峰 )。结论　彩色多普勒超声能成功用于检查上肢动脉 ,发现变异和病变。     

The cerebroplacental Doppler ratio revisited.

OBJECTIVE: To evaluate the distribution of Doppler pulsatility index (PI) measurements of the umbilical and middle cerebral arteries in singleton fetuses of women with normal uterine artery blood flow and to construct reference ranges for the cerebroplacental PI Doppler ratio. METHODS: The PI was determined in the mid-portion of the umbilical artery and the mid- or distal segment of the middle cerebral artery in 306 normal singleton fetuses. The cerebroplacental Doppler ratio (CPR) was determined from paired measurements. After determination of the best fit, reference ranges were constructed for each parameter against gestational age (GA). RESULTS: The PI for the umbilical artery had a linear relationship with GA (umbilical artery PI = - 0.0246 x GA + 1.7791, r(2) = 0.4025, P < 0.001). The middle cerebral artery PI and the CPR both showed a quadratic relationship with GA (middle cerebral artery PI = - 0.0058 x GA(2) + 0.3335 x GA - 2.7317, r(2) = 0.2365, P < 0.01), (CPR = - 0.0059 x GA(2) + 0.383 x GA - 4.0636, r(2) = 0.2788, P < 0.001). CONCLUSION: The CPR is not constant throughout gestation. Reference ranges constructed by a standardized Doppler technique may be of benefit in the monitoring of high-risk pregnancies.     

正常胎儿主肺动脉多普勒参数与孕周的关系

目的探讨正常胎儿妊娠中、晚期主肺动脉多普勒参数与孕周的关系。 方法将孕龄为21~40周的正常胎儿300例按照孕龄分为10组,分别为21~22^＋6周、23~24^＋6周、25~26^＋6周、27~28^＋6周、29~30^＋6、31~32^＋6周、33~34^＋6周、35~36^＋6周、37~38^＋6周和39~40^＋6周,每组30例。采用彩色超声仪测量收集正常胎儿主肺动脉多普勒参数：收缩期加速度时间（AT）、射血时间（ET）、收缩期峰值流速（PSV）、舒张期末流速（EDV）、平均流速（MV）、搏动指数（PI）和阻力指数（RI）。建立不同孕周主肺动脉多普勒参数的正常参考值,对各参数值和孕周进行相关和回归分析。 结果300例胎儿均获得满意的主肺动脉流速曲线,AT、AT/ET、PSV、EDV和MV与孕周呈线性正相关（r=0.866、0.848、0.457、0.242、0.506,P均<0.05）;PI与孕周呈线性负相关（r=-0.170,P<0.05）;ET、RI与孕周无相关性（r=0.195、-0.197,P均>0.05）。 结论正常胎儿主肺动脉多普勒参数与孕周有一定的相关性,AT、AT/ET与胎儿孕周相关性最好。     

Doppler blood flow velocity waveforms in the fetal renal arteries: variability at proximal and distal sites in the right and left arteries.

OBJECTIVE: To investigate variability in pulsatility/resistance indices and absolute velocities of blood flow in fetal renal arteries dependent on side and sampling site within each vessel. METHODS: Doppler blood flow measurements of pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV) and end-diastolic velocity (EDV) were performed in the renal arteries of 27 fetuses between 236 and 247 days of gestation. Velocity waveforms were sampled in both the right and left renal arteries at two different sites: proximally, close to the aorta, and distally, before any major visible bifurcation of the vessels. The intraobserver variation was measured in 15 additional fetuses. RESULTS: Mean values of PI and RI were similar in the right and left renal arteries and at the proximal and distal sampling sites of these arteries. Mean PSV and EDV were higher at the proximal compared to the distal site on both sides. For all parameters the 95% limits of agreement between measurements made in the right and left arteries and at proximal and distal sites were wide but tended to be narrower for the left renal artery and at the distal site. Intraclass correlation coefficients for intraobserver variability were 0.88, 0.89, 0.83 and 0.81 for PI, RI, PSV and EDV, respectively. CONCLUSIONS: It is important to standardize the precise site at which Doppler blood flow velocity waveform measurements are made in the renal arteries of the fetus. On the basis of our observations, we suggest that the left renal artery is the preferred vessel for sampling and that measurements should be made in the renal arterial trunk away from the aorta and before any visible branches.     

Association between intrapulmonary arterial Doppler parameters and degree of lung growth as measured by lung-to-head ratio in fetuses with congenital diaphragmatic hernia

OBJECTIVES: To describe the association between the intrapulmonary circulation and the degree of lung growth in fetuses with congenital diaphragmatic hernia (CDH). METHODS: Thirty-six fetuses with isolated left CDH at 22-29 weeks of gestation were studied. Four groups were defined according to lung-to-head ratio (LHR), expressed as the ratio of observed to expected LHR for gestational age (O/E LHR). Pulsatility index (PI), peak systolic velocity (PSV), peak early-diastolic reversed flow (PEDRF), end-diastolic velocity (EDV), acceleration time (AT), time averaged velocity (TAV) and the ratio AT to ejection time (AT/ET) were measured in all fetuses in the proximal arterial branch of both lungs. For analysis, Doppler values were converted to Z-scores. RESULTS: It was possible to record all Doppler parameters from the contralateral lung of all CDH fetuses, and from the ipsilateral lung in 28 (77.7%). PEDRF significantly increased in relation to the decrease in O/E LHR in both lungs (contralateral: r = - 0.65, P = 0.01; ipsilateral: r = - 0.43, P = 0.02). PI increased significantly with the reduction in O/E LHR but only on the side contralateral to the hernia (r = - 0.55, P = 0.02). In the ipsilateral pulmonary artery, PI values showed a significant overall increase but no differences were observed among the O/E LHR groups. PSV, EDV and TAV were reduced in both lungs with respect to normal values, but no association was found with the O/E LHR. No changes in AT or AT/ET were observed in either lung. CONCLUSIONS: PEDRF is quick and easy to calculate, and showed the strongest and most consistent correlation with O/E LHR. The association between PEDRF and LHR might be an additional parameter that could help to establish prognosis in fetuses with CDH.     

Value of Transthoracic Echocardiography for the Detection of High-Grade Coronary Artery Stenosis: Prospective Evaluation in 50 Consecutive Patients Scheduled for Coronary Angiography

We prospectively evaluated the feasibility of direct, transthoracic evaluation of coronary arteries to diagnose flow-limiting lesions. Second harmonic mode in B-mode and fundamental mode for Doppler examinations was used. A stenosis was diagnosed when maximal flow velocity at least doubled in comparison with that of the adjacent segment or when local velocity was at least 2 m/s. Of the left anterior descending coronary artery segments assessed, 34 were proximal, 35 middle, and 34 distal segments. The corresponding figures for circumflex coronary artery segments were 17 proximal and 11 middle segments and for the right coronary artery, 14 proximal and 15 distal segments. No distal circumflex and only 1 mid right coronary artery segment was visualized. Twenty-eight stenoses were diagnosed. Specificity for stenosis detection was 96% to 100% and sensitivity was 62% to 66%. Echo-cardiography was unable to document occlusions. Transthoracic echocardiography allows for coronary artery assessment in a significant portion of patients scheduled for coronary angiography. It may be used to document the presence of coronary artery stenosis. With further technologic improvements, transthoracic echocardiography could enable the monitoring of the restenosis process after percutaneous transluminal coronary angioplasty/stent intervention and coronary artery luminal narrowing after heart transplantation.     

正常胎儿主肺动脉多普勒流速曲线参数测值与孕龄相关性的研究

目的探讨正常胎儿主肺动脉多普勒流速曲线参数测值与孕龄的相关性。方法将孕龄为23～40周的252例正常胎儿按照孕龄分为10组,利用超声多普勒测量胎儿主肺动脉流速曲线参数：收缩期加速时间（AT）、射血时间（ET）、加速时间／射血时间（舳T）、收缩期峰值流速（PSV）、舒张期末流速（EDV）、平均流速（MV）、搏动指数（PI）、阻力指数（RI）。建立不同孕龄各流速曲线参数的正常参考值,对各参数与孕龄绘制散点图、进行相关和回归分析,选择最优化方程。结果252例正常胎儿中,胎儿主肺动脉多普勒流速曲线测量成功249例（98．8%,249／252）。胎儿主肺动脉多普勒流速曲线参数测值随孕龄增加的变化：AT、AT／ET、PSV、EDV、MV测值随孕龄增加而呈增大趋势（F=343．23、96．012、8．649、2．158、10．169,P均〈0．05）：PI测值随孕龄增加而呈减小趋势（F=2．346,P〈0．05）;ET、RI随孕龄增加测值无明显变化（F=0．883、1．534,P〉0．05）。AT、AT／ET、PSV、EDV、MV测值与孕龄呈显著线性正相关（r=0．898、0．868、0．446、0．203、0．507,P均〈0．01）;PI测值与孕龄呈显著线性负相关（r=-0．184,P〈0．01）;ET、RI测值与孕龄无相关性（r=-0．103、0．011,P均〉0．05）。结论胎儿主肺动脉为超声多普勒测量肺动脉流速曲线的可靠测量点。正常胎儿主肺动脉流速曲线参数与孕龄有一定相关性,AT、AT／ET与胎儿孕龄相关性最好。     

Screening for pre-eclampsia and fetal growth restriction by uterine artery Doppler and PAPP-A at 11-14 weeks' gestation.

OBJECTIVE: To assess the role of maternal demographic characteristics, uterine artery Doppler velocimetry, maternal serum pregnancy-associated plasma protein-A (PAPP-A) and their combination in screening for pre-eclampsia and small-for-gestational age (SGA) fetuses at 11-14 weeks. METHODS: This was a prospective study of 878 consecutive women presenting for a routine prenatal ultrasound examination at 11-14 weeks. Pulsed wave Doppler was then used to obtain uterine artery flow velocity waveforms and the mean pulsatility index (PI) of the uterine arteries was calculated. Maternal serum samples for PAPP-A were assayed. Along with maternal history, these measurements were compared in their ability to predict adverse outcome, defined as pre-eclampsia and/or SGA and/or placental abruption. RESULTS: Mean uterine artery PI > or = 95(th) centile and PAPP-A < or = 10(th) centile each predicted 23% of the women that developed pre-eclampsia and 43% of cases of placental abruption. For SGA < or = 5(th) centile, mean uterine artery PI > or = 95(th) centile predicted 23% of cases and PAPP-A < or = 10(th) centile predicted 34%. Independent predictors for subsequent development of pre-eclampsia were increased mean uterine artery PI > or = 95(th) centile (OR, 2.76; 95% CI, 1.11-6.81) and maternal history of pre-eclampsia/hypertension (OR, 50.54; 95% CI, 10.52-242.73). The predicting factors for SGA < or = 5(th) centile were increased mean uterine artery PI > or = 95(th) centile (OR, 2.0; 95% CI, 1.07-3.74) and low PAPP-A (OR, 0.43; 95% CI, 0.20-0.93). Increased uterine artery PI was the only independent factor in the prediction of placental abruption (OR, 8.49; 95% CI, 2.78-25.94). The combination of uterine artery PI and maternal history of pre-eclampsia/hypertension was better than was using uterine artery Doppler alone in predicting pre-eclampsia. Similarly, for the prediction of SGA < or = 5(th) centile, combining uterine artery Doppler and maternal serum PAPP-A was better than was uterine artery Doppler alone. In both cases, the difference approached statistical significance. CONCLUSIONS: The combination of maternal history with abnormal uterine artery Doppler and low PAPP-A level at 11-14 weeks achieves better results than does either test alone in the prediction of pre-eclampsia and SGA.     

Doppler changes in the main fetal brain arteries at different stages of hemodynamic adaptation in severe intrauterine growth restriction.

OBJECTIVE: To evaluate changes in the temporal evolution and regional distribution of arterial brain Doppler parameters in relation to different stages of hemodynamic adaptation in fetuses with severe intrauterine growth restriction (IUGR). METHODS: Thirty-six fetuses with severe IUGR ( 2 SD) were evaluated longitudinally with pulsed Doppler ultrasound at four different hemodynamic stages: Stage 1 (n = 36), mean UA-PI > 2 SD or absent UA end-diastolic flow; Stage 2 (n = 34), abnormal middle cerebral artery (MCA) PI (mean < 2 SD); Stage 3 (n = 30), reversed UA end-diastolic flow; Stage 4 (n = 12), absent or reversed atrial flow in the ductus venosus. In addition, 36 normally grown fetuses were studied for comparison. PI and time-averaged maximum velocity (TAMXV) in the MCA and the anterior cerebral (ACA), pericallosal (PER) and posterior cerebral (PCA) arteries were measured. RESULTS: In IUGR fetuses, PI values from all arteries were significantly reduced at Stage 2. At Stages 3 and 4, ACA-PI and PCA-PI did not change further, whereas MCA-PI and PER-PI showed a slight increase. In the ACA, MCA and PER, TAMXV in Stage 2 increased significantly. In Stages 3 and 4, ACA and PER-TAMXV remained unchanged, whereas MCA-TAMXV showed a slight decrease, mirroring the PI values. PCA-TAMXV values were similar to controls at all stages. CONCLUSION: In IUGR fetuses, the brain arteries differ in the magnitude and time sequence of Doppler parameters in relation to systemic hemodynamic adaptation, suggesting the existence of regional brain redistribution processes.     

Can umbilical artery pulsatility index predict the outcome of fetuses with structural heart disease?

Umbilical artery Doppler waveforms have been suggested to demonstrate diminished end-diastolic velocities in anomalous fetuses. We evaluated 11 fetuses with antenatally diagnosed congenital heart disease (CHD) and compared them to a normal population. Fetuses with CHD were studied once each and ranged in age from 19 to 32 weeks gestation. Eight had normal chromosomes, and three were aneuploid. The pulsatility index (PI) was elevated (above the 90th percentile for gestational age) in 3/11 CHD fetuses (P = NS). Elevated PI did not discriminate well between those with fatal and nonfatal lesions. Although all three fetuses with elevated PI had fatal disease, five of eight fetuses with fatal anomalies had normal PI values. We conclude that, while umbilical artery PI values were elevated in a subgroup of affected fetuses, this was not clinically helpful.     

微型探头血管超声在烟雾病患者搭桥术中的血流动力学评估

目的前瞻性研究微型探头血管超声（MVD）评估烟雾病（MMD）患者颞浅动脉-大脑中动脉（STA-MCA）搭桥术吻合血管通畅性的可行性及可靠性。 方法选取2012年7月至2017年12月在苏州大学附属第一医院神经外科经数字减影血管造影（DSA）确诊为烟雾病患者68例（83例次，其中15例为先后双侧手术）。术中应用MVD检测并分析供血动脉即STA顶支或额支、受血动脉即MCA分支M4在吻合前、后的血流动力学参数。设定吻合后STA脉动指数（PI）≤1.10为吻合血管通畅（即通畅组，57例），STA的PI值>1.10为血管通而不畅（即不通畅组，17例），STA仅为"单峰"收缩期血流信号，则血管不通（即不通组，9例）。手术前、后均行颈部血管超声（CDU）、CT灌注成像（CTP）、CT血管造影（CTA）和DSA检查。比较吻合前后STA、吻合前M4与吻合后M4近心段、吻合前M4与吻合后M4远心段血流动力学参数采用配对t检验，比较吻合后M4近心段与远心段血流动力学参数采用独立样本t检验，比较吻合后STA通畅组、不通畅组及不通组3组血流动力学参数的差异采用F检验，有统计学意义的组间采用LSD-t检验。 结果吻合前后STA：吻合后STA Vm、Vs、Vd明显升高且PI值明显减低，差异均有统计学意义（t=-5.32、-4.62、-5.68、8.96，P均<0.001），频谱呈"颅内动脉化"改变；吻合后3组之间比较，通畅组Vm、Vs、Vd最高且PI值最低，差异均有统计学意义（Vm：t=6.15，Vs：t=5.81、6.95，Vd：t=7.32，PI：t=-11.99、-15.31，P均<0.001），不通组Vs最低且PI值最高，差异均有统计学意义（Vs：t=4.15，PI：t=-6.08，P均<0.001）。所有吻合不通畅或不通的患者均经调整修正后再次检测，STA频谱均呈"颅内动脉化"改变。吻合前后M4：吻合后M4近心段及远心段Vm、Vs、Vd均明显升高且远心段PI值明显增高，差异均有统计学意义（近心段：t=-6.64、-7.73、-5.63，远心段：t=-4.35、-4.51、-3.99、-3.96，P均<0.001）；吻合后近心段Vm、Vs、Vd高于远心段，PI值低于远心段，差异均有统计学意义（t=2.58、2.31、2.69、2.49，P均<0.05），且近心段血流方向逆转（表明吻合通畅）。预后：所有患者术后4~7 d行CDU检查，95%（79/83）的患者STA频谱仍呈"颅内动脉化"改变，表明吻合血管通畅，与CTA结果一致，且CTP证实脑灌注改善；术后6个月~1年，行DSA检查，证实96%（80/83）吻合血管通畅。 结论MVD在MMD患者行STA-MCA搭桥术中可实时评估吻合血管的通畅性，且吻合后STA的PI值≤1.10可作为判断术中吻合血管通畅的可靠指标。     

Cerebral hemodynamics and fetal behavioral states.

OBJECTIVE: This study aimed to evaluate the hemodynamic patterns of the proximal (M1) and distal (M2) portions of the middle cerebral artery, during different fetal behavioral states. DESIGN: The study included 20 normal singleton pregnancies at between 36 and 40 weeks of gestation. After identification of the fetal behavioral state (FBS), flow velocity evaluation was performed on the proximal and distal segments of the middle cerebral artery during 'quiescence' (FBS-1F) and 'activity' (FBS-2F). RESULTS: A statistically significant decrease of pulsatility index, reflecting a decrease of impedance to flow values, was identified in both segments of the middle cerebral artery (MCA) during 'activity', with a more marked decrease in the MCA-M2 than in MCA-M1 (M1, P = 0.0028; M2, P = 0.00000085). The mean fetal heart rate during 'quiescence' was significantly lower than during 'activity' (P = 0.0047). However, there was no significant correlation between the pulsatility index of both segments of the middle cerebral artery and the fetal heart rate during different fetal behavioral states. CONCLUSIONS: The results of this study provide evidence of the influence of different fetal behavioral states on fetal cerebral hemodynamic patterns. We believe it is better to sample the proximal segment in clinical practice because it is less influenced by fetal behavioral state. This information should be considered when evaluating fetal cerebral hemodynamics.     

Three-dimensional, time-resolved motion of the coronary arteries.

BACKGROUND: Coronary artery motion can decrease image quality during coronary magnetic resonance angiography and computed tomography coronary angiography. PURPOSE: To characterize the three-dimensional motion of the coronary arteries along the entire vessel length and to identify the temporal location and duration of periods of relatively low cardiac motion in patients with coronary artery disease. METHODS: Archived digital, biplane x-ray angiography films acquired at 30 frames per second with simultaneous electrocardiogram recording were reviewed for 15 patients with coronary artery disease. The right coronary (RCA), left anterior descending (LAD), and left circumflex (LCX) arteries were divided into proximal, mid, and distal segments. The displacement and velocity of a point in each segment were calculated throughout the heart cycle. Time-dependent, three-dimensional motion of each segment on each vessel was determined. Periods of the heart cycle during which maximal displacement was less than 1 mm or 0.5 mm per frame for each artery were determined. RESULTS: A period lasting an average of 187 msec was seen during mid-diastole (72+/-5% of the cardiac cycle) in which all three coronary arteries studied had relatively little motion. This period of quiescence was consistent along the length of the arteries. Although the amount of motion did vary along the length of the arteries, there was no difference in the timing of rest periods in the proximal, mid, and distal segments using a < 1 mm per frame threshold. The periods of low motion were significantly reduced in length and often altogether eliminated when the 0.5 mm per frame threshold was used.     

血管组织重建中人与猪升主动脉、肺动脉干零应力状态的比较

背景:由于同种心移植器官来源有限,短缺问题日益突出,而猪的心血管系统及血液动力学方面与人类颇相似,猪→人异种心脏移植已成为国内外学者非常重视的课题,其基础研究日趋活跃。目的:比较正常成人与不同月龄猪升主动脉、肺动脉干的零应力状态,为猪→人异种心脏移植吻合血管提供必要的血管组织重建基础。设计:开放性实验。单位:郧阳医学院生物力学实验室。材料:实验于2001-10/2002-09在郧阳医学院医用生物力学实验室完成。人的心脏标本取自无心血管疾病、年龄18～30岁的6例成年男性尸体,均经家属同意。另选取1月龄同种猪42只,分为7组,分别为1,2,3,4,5,6,>6月龄组,每组6只,各组分别于1,2,3,4,5,6,>6月龄时麻醉屠宰。方法:解剖分离相应升主动脉和肺动脉干,用着色笔原位标记各动脉前壁后,将动脉移至氧饱和的Kreb’s液后,沿其轴向均分为5个等长的血管环,再沿径向剪开各血管环,20min后由计算机记录并测量各血管环的零应力状态张开角(张开的血管面内壁中点和内壁两端点连线的夹角)。实验温度为室温20～30℃。所有血管试样的实验操作均在观察对象死后24h内完成。主要观察指标:人与不同月龄猪升主动脉、肺动脉干零应力状态张开角的测定结果。结果:①人与不同月龄猪升主动脉、肺动脉干零应力状态张开角的测定结果比较:人升主动脉的张开角从近侧端的(100.4±12.8)°增至远侧端的(152.8±18.6)°,各月龄猪升主动脉的张开角从近侧端的68°左右增至远侧端的130°左右;人肺动脉干的张开角沿轴向无明显变化,各月龄猪肺动脉干的张开角从近侧端的65°左右增至远侧端的125°左右。人和猪升主动脉、肺动脉干零应力状态张开角比较差异有显著性意义(P=0.028<0.05)。但人升主动脉第2区段和各月龄组猪第4,5区段的张开角相近;肺动脉干各区段与猪肺动脉干近侧端(第1,2区段)的张开角相近。②不同月龄猪升主动脉、肺动脉干零应力状态张开角的测定结果比较:猪升主动脉、肺动脉干的张开角不随年龄增加而发生变化(P=0.063>0.05)。结论:在某些区段人和猪升主动脉、肺动脉干的零应力状态张开角相近,提示猪→人异种心脏移植中相应升主动脉和肺动脉干在某些区段可以相互吻接,而且年龄因素在血管重建过程中的作用并不显著。     

Quantitative angiographic follow-up studies on the development of coronary artery disease: which coronary segments should be analyzed?

Angiographic follow-up studies on the evolution of coronary artery disease are of increasing relevance. It has still to be evaluated which coronary segments are predominantly involved in the process of atherosclerosis and, thus, should be preferably included in the analysis. Therefore, the correlation of progression and regression of coronary disease with the diameter and location (proximal, mid or distal) of coronary segments was investigated from the data of the INTACT-study, in which 25 different coronary segments were defined including anatomic variants of rather distal segments. In 348 patients with coronary artery disease, standardized coronary angiograms were repeated within 3 years and were quantitatively analyzed (CAAS). In 1063 coronary stenoses (% diameter stenosis > 20%) compared from both angiograms, progression and regression were not influenced by diameter nor location of arterial segments. In the follow-up angiograms, the number of new lesions (stenoses and occlusions) per coronary segment differed with regard to segment diameter (> 3 mm: 64/1125 (6%); 2–3 mm: 139/1967 (7%);<2 mm: 44/1756 (2%); p<0.001) and location of segments (proximal: 86/1285 (7%); mid: 84/1193 (7%); distal: 77/2370 (3%); p<0.001). Out of 77 distal new lesions, only 25 (32%) were found in segments<2 mm in diameter. Since the absolute number of new lesions was high in distal coronary segments, but low in segments with diameters<2 mm, angiographic follow-up studies should analyze coronary segments at any location, but may neglect segments with diameters smaller than 2 mm.     

Ductus venosus shunting in marmoset and baboon fetuses.

OBJECTIVES: The increased shunting of blood through the ductus venosus (DV) during stress situations is an important mechanism that ensures fetal survival. Although primate fetuses may serve to study the function of this important venous shunt, the rate of DV shunting has not been determined in non-human primates under normal conditions. METHODS: DV shunting was measured in 11 marmoset (eight mothers) and eight singleton baboon fetuses in mid and late gestation using Doppler ultrasound. RESULTS: DV shunting in marmosets was 39 +/- 20% (mean +/- SD) and 28 +/- 8% in baboon fetuses. Umbilical vein (UV) blood volume rate increased significantly in baboons with gestational age (GA) (UV flow volume = -111.8 + 1.6*GA; r = 0.94, P < 0.05) and slightly in marmosets (UV flow volume = -10.37 + 0.13*GA; r = 0.42, P > 0.05). Both UV diameter (r = 0.84) and the time-averaged mean UV flow velocity in baboons depended on GA (r = 0.8, P < 0.05). Distinct pulsation was found in marmoset fetuses in the UV (pulsatility index (PI) = 1.3 +/- 0.9) and the DV (PI = 1.9 +/- 1.2) with zero blood flow velocity during atrial contraction. CONCLUSIONS: A high level of pulsation is observed in the UV in marmoset fetuses. DV shunting in marmosets is higher than in baboon fetuses.     

Doppler evaluation of the uterine and spiral arteries from different sampling sites and phases of the menstrual cycle during controlled ovarian hyperstimulation.

OBJECTIVE: To compare the pulsatility index (PI) and resistance index (RI) at different sampling sites of the uterine and spiral arteries in the early and mid-menstrual phases. MATERIALS AND METHODS: The uterine and spiral arteries of 110 women undergoing similar ovarian hyperstimulation and intra-uterine insemination regimes were examined using transvaginal color Doppler ultrasound. The uterine artery was sampled at five sites: (1) ascending branch; (2) descending branch; (3) proximal, near branch division; (4) mid, 0.5 cm distal to the division; (5) lateral location, 1 cm distal to the division. The spiral artery was sampled at three sites: (a) anterior; (b) fundal; (c) posterior. The uterine and spiral arteries were examined twice, on days 2-3 and 14-16, respectively, of the menstrual cycle. The women were also grouped according to age at examination, < or = 30 years and > 30 years. The PI and RI values for different sites, menstrual phase, and age were compared. RESULTS: The mean PI and RI values of the uterine artery were: (1) 2.86 +/- 1.20 and 0.92 +/- 0.13; (2) 2.66 +/- 1.15 and 0.89 +/- 0.12; (3) 2.88 +/- 1.26 and 0.90 +/- 0.15; (4) 3.03 +/- 1.02 and 0.91 +/- 0.07; (5) 3.23 +/- 1.38 and 0.89 +/- 0.12; and of the spiral artery were (a) 1.61 +/- 1.01 and 0.69 +/- 0.17; (b) 1.69 +/- 0.74 and 0.74 +/- 0.17; (c) 1.73 +/- 0.86 and 0.68 +/- 0.17. The PI values for uterine and spiral arteries at two phases of the menstrual cycle were 2.92 +/- 1.18 and 1.55 +/- 0.72 (days 2-3); 3.11 +/- 1.15 and 1.80 +/- 1.02 (days 14-16), respectively; for younger women (age < or = 30 years) these values were 2.83 +/- 1.22 and 1.6 +/- 0.85 and for older women (age > 30 years) 3.0 +/- 1.34 and 1.72 +/- 0.96, respectively. CONCLUSIONS: There were no significant differences in PI and RI values of the uterine and spiral arteries at different sampling sites, phase of the menstrual cycle or age. The higher PI values tended to occur in the lateral uterine artery and posterior spiral artery, during the mid-menstrual phase and in the older age group. The PI and RI values of the mid-uterine and fundal spiral artery sampling sites are representative of the whole uterine artery and spiral artery, respectively.