Effect of hypoxic hypoxia on systemic vasculature

1984 ◽  
Vol 56 (5) ◽  
pp. 1403-1410 ◽  
Author(s):  
J. Malo ◽  
H. Goldberg ◽  
R. Graham ◽  
H. Unruh ◽  
C. Skoog
Keyword(s):  
Arterial Pressure ◽  
Inferior Vena ◽  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Venous Drainage ◽  
Hypoxic Hypoxia ◽  
Venous Compliance ◽  
Flow Curves ◽  
Pressure Flow

Effects of hypoxic hypoxia (HH) on cardiac output (CO), CO distribution, arterial and venous pressure-flow curves, vascular compliance, vascular time constant (tau), and resistance to venous return (RVR) were evaluated on six dogs. The vascular bed was isolated into four compartments depending on venous drainage: superior vena cava (SVC), splanchnic, renal and adrenal, and the remainder of the inferior vena cava (IVC). Low arterial O2 content and PO2 produced a threefold increase in CO at the same mean arterial pressure and a significant redistribution of CO to the SVC. Arterial pressure-flow curves decreased their slope (i.e., flow resistance) by a factor of two in the IVC and renal beds and by a factor of three in the splanchnic and SVC beds. Venous pressure-flow curves for the animal also decreased their slope significantly. HH causes a twofold increase in venous compliance and in mean venous pressure; tau did not change, but RVR halved. Seventy percent of the CO increase is explained by the increase in mean venous pressure and 30% by the reduction in RVR.

Effect of sympathectomy on arterial and venous changes in renal hypertensive rats

1981 ◽  
Vol 241 (3) ◽  
pp. H449-H454
Author(s):  
G. Simon
Keyword(s):  
Arterial Pressure ◽  
Structural Changes ◽  
Venous Pressure ◽  
Vena Cava ◽  
Hypertensive Rats ◽  
Flow Curves ◽  
Pressure Flow ◽  
Pressure Axis ◽  
Arteries And Veins ◽  
Renal Hypertensive Rats

Arterial pressure-flow and venous pressure-volume relationships were measured at maximal vasodilatation in the denervated pump-perfused hindquarters of four groups of rats: 1) neonatally sympathectomized (guanethidine-injected and adrenal-demedullated), one-kidney, one-clip hypertensive (n = 9); 2) sympathectomized, sham-operated, unilaterally nephrectomized control (n = 10); 3) sham-sympathectomized, one-kidney, one-clip hypertensive (n = 8); and 4) sham-sympathectomized, sham-operated, unilaterally nephrectomized control (n = 9). Dry defatted weight of anatomically defined segments of the aorta and vena cava in the four groups of rats also was measured. Significant rises in arterial pressure developed in sympathectomized rats after clipping of the renal artery and contralateral nephrectomy. Arterial pressure-flow curves were shifted toward the pressure axis (P less than 0.01) in clipped rats whether sympathectomized or not. In sympathectomized clipped rats, there was also a shift of the venous pressure-volume curves toward the pressure axis (P less than 0.05). The same degree of hypertrophy of the aorta was found in sympathectomized and sham-sympathectomized clipped rats. The findings indicate that in renal hypertensive rats structural changes of both large arteries and veins may develop in the absence of an intact sympathoadrenergic system.

Venous anomalies

2017 ◽  
Author(s):  
Sara Thorne ◽  
Sarah Bowater
Keyword(s):  
Inferior Vena Cava ◽  
Superior Vena Cava ◽  
Inferior Vena ◽  
Superior Vena ◽  
Vena Cava ◽  
Venous Drainage ◽  
Scimitar Syndrome ◽  
Anomalous Pulmonary Venous Drainage ◽  
Venous Anomalies

This chapster discusses anomalies of systemic venous drainage and anomalies of pulmonary venous drainage. It discusses superior vena cava (SVC) anomalies, inferior vena cava (IVC), total anomalous pulmonary venous drainage (TAPVD), partial anomalous pulmonary venous drainage (PAPVD), and scimitar syndrome.

Effect of pulsatile pressure and metabolic rate on intestinal autoregulation

1982 ◽  
Vol 242 (5) ◽  
pp. H769-H775 ◽  
Author(s):  
A. P. Shepherd ◽  
G. L. Riedel
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Metabolic Rate ◽  
Venous Pressure ◽  
Systematic Effect ◽  
Flow Curves ◽  
Pressure Flow ◽  
Pulsatile Pressure ◽  
Series Of Experiments ◽  
Pressure Autoregulation

In the intestine, raising venous pressure elicits a precapillary vasoconstriction that has been ascribed to a myogenic mechanism. Such myogenic responses occur more frequently and have a greater magnitude if arterial pressure is pulsatile. This laboratory reported that the ability of the gut to autoregulate blood flow in response to perfusion pressure manipulations is enhanced if metabolic rate is stimulated by transportable intraluminal solutes. Since both myogenic and metabolic mechanisms may participate in local control, we attempted to delineate the relative contributions the two mechanisms make to autoregulation. In one set of experiments, pulse pressures of 20 and 40 mmHg evoked a slight but statistically significant vasoconstriction. In a second series of experiments, pressure-flow curves were determined in isolated canine small bowel. The ability of the gut to autoregulate was compared at pulse pressures of 0, 20, and 40 mmHg and at basal and elevated metabolic rates. Altering pulse pressure had no systematic effect on the ability of the intestine to autoregulate blood flow. In contrast, increasing metabolic rate consistently enhanced autoregulation at each of the pulse pressures studied. Therefore, these results indicate that although a myogenic mechanism may best account for the response to elevated venous pressure, autoregulation as expressed in pressure-flow curves is more strongly influenced by the prevailing metabolic rate than by stretch stimuli such as arterial pressure pulsations.

Unusual Venacaval Anomalies in a Patient with Atrial Septal Defect

2008 ◽  
Vol 16 (6) ◽  
pp. 492-494 ◽  
Author(s):  
Sai S Oruganti ◽  
Pankaj Jariwala ◽  
Amit K Taggarse ◽  
Ramesh C Mishra
Keyword(s):  
Atrial Septal Defect ◽  
Superior Vena Cava ◽  
Septal Defect ◽  
Inferior Vena ◽  
Superior Vena ◽  
Pulmonary Stenosis ◽  
Vena Cava ◽  
Venous Drainage ◽  
Drainage Pattern ◽  
Left Superior Vena Cava

An unusual systemic venous drainage pattern was found in a 30-year-old man with ostium secundum atrial septal defect and pulmonary stenosis. He had the rare association of absent right superior vena cava, persistent left superior vena cava draining into the coronary sinus, and a left-sided inferior vena cava draining into a left superior vena cava through the hemiazygous vein.

scholarly journals PARTICULARITIES OF SCIMITAR SYNDROME IN ADULT PATIENTS

2021 ◽  
Vol 9 (5) ◽  
pp. 1274-1278
Author(s):  
Soumia Faid ◽  
◽  
Amine Maliki Alaoui ◽  
Nadif Maryam ◽  
Liban Ibrahim ◽  
...  
Keyword(s):  
Inferior Vena Cava ◽  
Right Atrium ◽  
Inferior Vena ◽  
Superior Vena ◽  
Pulmonary Veins ◽  
Vena Cava ◽  
Venous Drainage ◽  
Scimitar Syndrome ◽  
Chest X Ray ◽  
The Right

Scimitar syndrome or Felsons veno-lobar syndrome is a very rare congenital disease characterized by a combination of cardiopulmonary abnormalities, including partial right-sided pulmonary venous drainage to the inferior vena cava, the inferior cavo-atrial junction, or low on the right atrium. We report the case of a 53-year-old female patient who presented with recent gradually worsening dyspnea. The diagnosis was suspected on the chest x-ray and confirmed on Cardiac echography andComputed Tomography scan that showed a wide collector gathering the three right superior pulmonary veins that joins the lower part of the superior vena cava, thus joining the right atrium while the right inferior pulmonary vein is drained into the inferior vena cava. The patient was treated surgically by performing a derivation of the right superior pulmonary venous collector to the left atrium with a tricuspid annuloplasty with a good outcome.

Caveats on Abdominal Central Venous Pressure Measurement

PEDIATRICS ◽  
1992 ◽  
Vol 90 (3) ◽  
pp. 479-479
Author(s):  
THOMAS R. LLOYD ◽  
RICHARD L. DONNERSTEIN ◽  
ROBERT A. BERG
Keyword(s):  
Inferior Vena Cava ◽  
Pressure Measurement ◽  
Inferior Vena ◽  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Right Atrial ◽  
Central Venous ◽  
Intraperitoneal Pressure ◽  
Extrinsic Compression

In Reply.— We appreciate Dr Tong's kind comments on our study. As we stated, "Abdominal vena cava pressure may be significantly higher than right atrial pressure...(in) patients with extrinsic compression of the inferior vena cava," and this may well occur in patients with severely elevated intraperitoneal pressure due to the presence of fluid or air. It is worth pointing out that the same caveat applies to intrathoracic venous pressure measurement in the presence of extrinsic compression of the superior vena cava or right atrium (eg, by pneumomediastinum).

Anomalies of systemic venous drainage

2011 ◽  
Keyword(s):  
Inferior Vena Cava ◽  
Superior Vena Cava ◽  
Inferior Vena ◽  
Superior Vena ◽  
Vena Cava ◽  
Venous Drainage ◽  
Complex Disorder

Introduction 130Superior vena cava (SVC) anomalies 130Inferior vena cava (IVC) anomalies 132Commonly seen as part of complex disorder.Occurs due to failure of the LSVC to obliterate during embryogenesis.• Usually drains into RA via CS.• RSVC usually present too....

scholarly journals Intra-Abdominal Venous Pressure During Laparoscopic Cholecystectomy

HPB Surgery ◽  
1994 ◽  
Vol 8 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Kazuhiro Iwase ◽  
Tetsuto Takao ◽  
Hirotoshi Watanabe ◽  
Yasuhiro Tanaka ◽  
Tetsuo Kido ◽  
...  
Keyword(s):  
Laparoscopic Cholecystectomy ◽  
Inferior Vena Cava ◽  
Superior Vena Cava ◽  
Inferior Vena ◽  
Superior Vena ◽  
Operative Procedure ◽  
Venous Pressure ◽  
Vena Cava ◽  
Abdominal Pressure ◽  
The Right

Superior vena cava (SVC) and inferior vena cava (IVC) pressures were measured serially during laparoscopic cholecystectomy in which the intra-abdominal pressure was maintained at 12mmHg. The influences of alteration of position from 15 degrees head-down to 15 degrees head-up and of the operative procedure of holding the gallbladder up to the right subphrenic space on SVC and IVC pressures were mild. IVC pressure was maintained almost equal to the intra-abdominal pressure during prolonged continuous pneumoperitoneum lasting longer than 60min, while SVC pressure did not change significantly during operation. The discrepancy between SVC and IVC pressures underwent no change during continuous pneumoperitoneum.

Postural changes in venous pressure gradients in anesthetized monkeys

1993 ◽  
Vol 264 (1) ◽  
pp. H21-H25 ◽  
Author(s):  
N. Terada ◽  
T. Takeuchi
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Pressure Gradients ◽  
Anatomic Structure ◽  
Postural Changes ◽  
Hydrostatic Load ◽  
Head Up Tilt

We examined the hypothesis that head-up and head-down tilt produce a symmetrical hydrostatic load on the veins. Venous pressure was measured in anesthetized monkeys with a transducer-tipped catheter. Changes in venous pressure gradients during head-up tilt corresponded to changes in hydrostatic load. However, changes in venous pressure gradients during head-down tilt were not symmetrical to those during head-up tilt. During head-down tilt, venous pressure in the superior vena cava rose, venous pressure around the right atrium did not change, and venous pressure in the inferior vena cava on the caudal side of the diaphragm rose considerably. The venous pressure of the inferior vena cava caudal to the renal vein then gradually decreased. The inferior vena cava passes through the central tendon of the diaphragm. Thus, during head-down tilt, the gravitational shift of venous blood is impeded by this anatomic structure, and venous pressure around the hepatic vein increases significantly. These data disproved our hypothesis that head-up and head-down tilt induced symmetrical but opposite influences on vena caval pressures.

Congenital Horner and Scimitar syndrome in a newborn: a previously unreported combination

2020 ◽  
Vol 13 (11) ◽  
pp. e238018
Author(s):  
Joana Carvalho ◽  
Mariana Maia ◽  
Ágata Mota ◽  
Teresa Martins
Keyword(s):  
Multidisciplinary Approach ◽  
Septal Defect ◽  
Inferior Vena ◽  
Superior Vena ◽  
Pulmonary Veins ◽  
Vena Cava ◽  
Scimitar Syndrome ◽  
Left Superior Vena Cava ◽  
Dilated Coronary Sinus ◽  
Rule Out

Here we report a case of a term newborn presenting with left palpebral ptosis, anisocoria and heterochromia as well as cleft palate and heart murmur. Congenital Horner syndrome was suspected and a thoracoabdominal CT scan was performed to rule out neuroblastoma. This revealed an anomalous drainage of right pulmonary veins to a collector that drains to the inferior vena cava, leading to the diagnosis of Scimitar syndrome. Echocardiogram showed an ostium secundum atrial septal defect, enlarged right chambers and a dilated coronary sinus due to a persistent left superior vena cava. The combination of Horner and Scimitar syndrome has never been described before. This case should encourage clinicians to use a multidisciplinary approach in order to guarantee an adequate diagnosis and management.

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