Pulsed wave Doppler velocimetry in the descending aorta of chronically instrumented fetal sheep

1990 ◽  
Vol 18 (4) ◽  
pp. 245-254 ◽  
Author(s):  
Bernd Hüneke ◽  
Hobe Johannes Schröder ◽  
Martin Hinrich Carstensen ◽  
Heinz-Peter Leichtweiß
Keyword(s):  
Doppler Velocimetry ◽  
Fetal Sheep ◽  
Descending Aorta ◽  
Pulsed Wave Doppler

Abstract 12320: Assessment of Post-Procedural Aortic Regurgitation After Transcatheter Aortic Valve Replacement During the Procedure: An Intraprocedural Transesophageal Echocardiography Study

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Hirotsugu Mihara ◽  
Kentaro Shibayama ◽  
Hasan Jilaihawi ◽  
Yuji Itabashi ◽  
Javier Berdejo ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Transesophageal Echocardiography ◽  
Aortic Regurgitation ◽  
Valve Replacement ◽  
Transcatheter Aortic Valve Replacement ◽  
Color Doppler ◽  
Descending Aorta ◽  
Transcatheter Aortic Valve ◽  
Pulsed Wave Doppler

Introduction: The assessment of post-procedual aortic regurgitation (PAR) after transcatheter aortic valve replacement (TAVR) has not been validated. The purpose of this study was (1) to investigate the value of holodiastolic flow reversal (HDFR) in the descending aorta in patients with PAR after TAVR and (2) to determine which color Doppler parameters are useful for PAR grading using the intraprocedural transesophageal echocardiography (iTEE). Hypothesis: We hypothesized that HDFR in the descending aorta and any color Doppler parameters can delineate significant PAR after TAVR. Methods: Three hundred-eighty patients with severe aortic stenosis underwent TAVR with the Edwards SAPIEN valve with 131 pulsed-wave Doppler tracings from the descending aorta had assessed by iTEE. PAR was evaluated using 2D color Doppler by the cross-sectional area of the vena contracta (VCA) at the aortic annular plane, and by the longitudinal jet extent (mosaic signals, Figure A) compared to the location of the tip of the anterior mitral leaflet (AML). Significant PAR was defined as VCA of ≥10 mm2, corresponding to greater than a moderate grade. Results: In patients with any grade of PAR, pulsed-wave Doppler tracing from the descending aorta, jet extent and VCA were obtained in 100%, 80%, and 74%, respectively. All patients with consistent HDFR had significant PAR. By multivariate analysis, a consistent HDFR and jet extent beyond the tip of AML were independent predictors of significant PAR. A consistent HDFR and jet extent beyond the tip of AML predicted significant PAR with specificity of 100% and 97%, respectively. In the other hand, patients with both negative HDFR and jet extent of less than halfway to the tip of AML had no significant PAR with a 97% specificity. Conclusions: The presence of HDFR with each cardiac cycle and jet extent beyond the tip of AML are indicative of significant PAR.

Peripheral chemoreflex activation and cardiac function during hypoxemia in near term fetal sheep without placental compromise

2021 ◽  
Author(s):  
Juulia Lantto ◽  
Tiina Erkinaro ◽  
Mervi Haapsamo ◽  
Heikki Huhta ◽  
Leena Alanne ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Carotid Artery ◽  
Arterial Oxygen ◽  
Sheep Model ◽  
Fetal Sheep ◽  
Descending Aorta ◽  
Arterial Blood ◽  
Near Term ◽  
Peripheral Chemoreflex

A drop in arterial oxygen content activates fetal chemoreflex including an increase in sympathetic activity leading to peripheral vasoconstriction and redistribution of blood flow to protect the brain, myocardium, and adrenal glands. By using a chronically instrumented fetal sheep model with intact placental circulation at near-term gestation, we investigated the relationship between peripheral chemoreflex activation induced by hypoxemia and central hemodynamics. 17 Åland landrace sheep fetuses at 115-128/145 gestational days were instrumented. Carotid artery was catheterised in 10 fetuses and descending aorta in 7 fetuses. After a 4-day recovery, baseline measurements of fetal arterial blood pressures, blood gas values, and fetal cardiovascular hemodynamics by pulsed Doppler ultrasonography were obtained under isoflurane-anesthesia. Comparable data to baseline was collected 10 (acute hypoxemia) and 60 minutes (prolonged hypoxemia) after maternal hypo-oxygenation to saturation level of 70-80% was achieved. During prolonged hypoxemia, pH and base excess (BE) were lower, and lactate levels higher in the descending aorta than in the carotid artery. During hypoxemia mean arterial blood pressure (MAP) in the descending aorta increased, while in the carotid artery MAP decreased. In addition, right pulmonary artery pulsatility index values increased, and the diastolic component in the aortic isthmus blood flow velocity waveform became more retrograde. Both fetal ventricular cardiac outputs were maintained even during prolonged hypoxemia when significant fetal metabolic acidemia developed. Fetal chemoreflex activation induced by hypoxemia decreased the perfusion pressure in the cerebral circulation. Fetal weight-indexed LVCO or AoI Net Flow-ratio did not correlate with a drop in carotid artery blood pressure.

Assessment of the severity of aortic regurgitation with pulsed wave Doppler velocity profile in the descending aorta

2014 ◽  
Vol 14 (5) ◽  
pp. 427-433
Author(s):  
Belma Kalayci ◽  
Suleyman Kalayci ◽  
Pinar Turker Bayir ◽  
Serkan Duyuler ◽  
Saadet Guven ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Aortic Regurgitation ◽  
Doppler Velocity ◽  
Descending Aorta ◽  
Pulsed Wave Doppler

Metabolic responses of the kidney in fetal sheep: effect of acute and spontaneous hypoxemia

1985 ◽  
Vol 249 (6) ◽  
pp. F836-F841 ◽  
Author(s):  
H. S. Iwamoto ◽  
A. M. Rudolph
Keyword(s):  
Left Renal Vein ◽  
Vena Cava ◽  
O2 Consumption ◽  
Renal Metabolism ◽  
Fetal Sheep ◽  
Descending Aorta ◽  
Lactate Uptake ◽  
Net Flux ◽  
Fetal Oxygenation ◽  
Arterial Po2

To examine the effects of hypoxemia on carbohydrate and O2 consumption by the fetal kidney, we inserted catheters into the descending aorta, inferior vena cava, and left renal vein of 14 fetal sheep at 120-130 days gestation. Three to nine days after surgery, nine fetuses had an arterial PO2 of 22 +/- 2 mmHg and O2 content of 2.68 +/- 0.65 mM. In these fetuses, the kidneys consumed O2 (107 +/- 21 mumol X min-1 X 100 g-1, mean +/- SD) and lactate (14 +/- 9.6 mumol X min-1 X 100 g-1) but produced glucose (5.6 +/- 6.5 mumol X min-1 X 100 g-1; 95% confidence limits, 0.62 and 10.5). When acute hypoxemia was induced by decreasing maternal fractional inspired O2 (FIO2) to 0.09, renal O2 consumption fell slightly (to 82 +/- 21 mumol X min-1 X 100 g-1), and there was net glucose uptake and net lactate release. A group of five fetuses was spontaneously hypoxemic 3-5 days after surgery and had an arterial PO2 of 14 +/- 2 mmHg and O2 content of 1.99 +/- 0.51 mM. Renal blood flow and O2 consumption were greater in these fetuses than in the normoxemic fetuses. There was net lactate uptake and no net flux of glucose across the renal circulation. These results demonstrate that renal metabolism of carbohydrate is altered by changes in fetal oxygenation.

Umbilical and hepatic venous responses to circulating vasoconstrictive hormones in fetal lamb

1991 ◽  
Vol 260 (4) ◽  
pp. H1205-H1213 ◽  
Author(s):  
R. P. Paulick ◽  
R. L. Meyers ◽  
C. D. Rudolph ◽  
A. M. Rudolph
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Vascular Resistance ◽  
Ductus Venosus ◽  
Dependent Manner ◽  
Outflow Resistance ◽  
Fetal Sheep ◽  
Descending Aorta ◽  
Placental Blood ◽  
Dose Dependent

Acute fetal hypoxemia increases the vascular resistance of the umbilical veins as well as that of the liver. Because, at least in the human, the umbilical-placental circulation has no autonomic innervation, circulating hormones could well be responsible for this increase in umbilical-placental outflow resistance. In chronically instrumented fetal sheep, norepinephrine, epinephrine, vasopressin, and angiotensin II were infused in sequentially increasing doses into the descending aorta and vascular resistance to umbilical-placental blood flow was measured. Norepinephrine and epinephrine increased the vascular resistance of the umbilical veins in a dose-dependent manner. Both catecholamines also increased the vascular resistance of the liver, resulting in an increase in ductus venosus blood flow. In contrast, vasopressin and angiotensin II had no effect on umbilical-placental outflow resistance. Thus catecholamines may be responsible for the increase in the vascular resistance of the umbilical veins and liver in response to acute fetal hypoxemia.

scholarly journals Fetal Dual Doppler Echocardiography

2014 ◽  
Vol 8 (4) ◽  
pp. 376-381
Author(s):  
Takashi Kaji ◽  
Kazuhisa Maeda ◽  
Atsuko Hichijo ◽  
Yohei Takahashi ◽  
Soichiro Nakayama ◽  
...  
Keyword(s):  
Doppler Echocardiography ◽  
Cardiac Rhythm ◽  
Simultaneous Recording ◽  
Image Resolution ◽  
Descending Aorta ◽  
Doppler Signals ◽  
Precise Diagnosis ◽  
Pulsed Wave Doppler ◽  
A New Technique ◽  
Fetal Position

ABSTRACT Dual Doppler echocardiography is a recently developed technique performed using an instrument with two separate sample gates, allowing simultaneous recording of signals from two locations. We describe the use of dual Doppler echocardiography to assess fetal cardiac rhythm. Fetal arrhythmias are common and encountered in 1 to 2% pregnancies. They often resolve spontaneously and do not require treatment, but sometimes lead to severe morbidity and mortality. Fetal arrhythmias are responsive to fetal therapy and require appropriate management through accurate diagnosis. Pulsed wave Doppler and M-mode echocardiography are widely used to assess fetal cardiac rhythm. Both methods have advantages and limitations, which are influenced by fetal position, image resolution, and the complexity of the arrhythmia. We developed a new technique that records pulsed wave Doppler signals in the hepatic vein (HV) and the descending aorta (DAo) simultaneously using dual Doppler. This method is less influenced by fetal position and the complexity of the arrhythmia, and the images have better resolution than those acquired using conventional Doppler methods in most cases. Although, electrical parameters, such as the QT interval cannot be evaluated, dual Doppler recording of flows in HV and DAo is an efficient and effective method for assessing fetal cardiac rhythms, allowing precise diagnosis of cardiac arrhythmias. How to cite this article Kaji T, Maeda K, Hichijo A, Takahashi Y, Nakayama S, Irahara M. Fetal Dual Doppler Echocardiography. Donald School J Ultrasound Obstet Gynecol 2014; 8(4):376-381.

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