Progressive changes in cardiovascular function after unilateral heart irradiation

1964 ◽  
Vol 206 (2) ◽  
pp. 289-293 ◽  
Author(s):  
H. L. Stone ◽  
V. S. Bishop ◽  
A. C. Guyton
Keyword(s):  
Left Ventricle ◽  
Arterial Pressure ◽  
Blood Volume ◽  
Pulse Rate ◽  
Left Atrial ◽  
Pressure Pulse ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Before And After ◽  
The Right

Chronic heart failure was produced by giving 20,000 r Co60 irradiation to either the right or left ventricle in nine closed-chest animals. Measurements of right and left atrial pressures, arterial pressure, pulse rate, body weight, and blood volume were made before and after irradiation. The right and left atrial pressures rose progressively until death in three animals irradiated on the right side. In six animals irradiated on the left side, the left atrial pressure rose progressively, but the right atrial pressure either did not rise or rose only during the latter stages of failure. Declining arterial pressure and increasing pulse rate were common to both groups. Increases in blood volume were observed in all animals, but this increase was only significant in the group irradiated on the left side. At autopsy, 70–100% of the right ventricular muscle was damaged in dogs irradiated on the right side, and 40–70% of the left ventricle in dogs irradiated on the left side. Hydrothorax and liver congestion were found in the right-sided group and pulmonary congestion in the left-sided group.

Control of atrial natriuretic factor by right and left atrial distension in pregnant sheep

1995 ◽  
Vol 268 (6) ◽  
pp. R1411-R1417
Author(s):  
D. Javeshghani ◽  
S. Mukaddam-Daher ◽  
L. Fan ◽  
Z. Guan ◽  
J. Gutkowska ◽  
...  
Keyword(s):  
Atrial Natriuretic Factor ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Natriuretic Factor ◽  
Pregnant Sheep ◽  
Vascular Catheters ◽  
The Right ◽  
Left Atrial Distension ◽  
Atrial Natriuretic

Previous studies of the atrial stretch-atrial natriuretic factor (ANF) relationship during pregnancy have employed volume expansion and measured only right atrial pressure (RAP). Consequently, we studied nonpregnant (n = 7) and 115- to 125-day pregnant (n = 7) sheep and assessed the ANF response to changes of RAP and left atrial pressure (LAP) induced by graded balloon inflation. Ewes prepared with vascular catheters and atrial balloons were studied after recovery from preparatory surgical procedures. The basal levels of mean arterial pressure (MAP, 83 +/- 3 mmHg), RAP (2.1 +/- 0.7 mmHg), LAP (4.7 +/- 0.9 mmHg), and heart rate (HR, 102 +/- 6 beats/min) were similar in nonpregnant and pregnant sheep. Pregnancy also resulted in elevation of ANF concentration from 25 +/- 6 to 57 +/- 4 fmol/ml. With right atrial distension, the RAP-ANF relationships were similar in both nonpregnant and pregnant sheep, with a 10-mmHg increase in RAP increasing ANF by an average of 95 +/- 9 fmol/ml. In nonpregnant sheep, the LAP-ANF relationship was more responsive than RAP-ANF because a 10-mmHg increase in LAP resulted in a 193 +/- 10 fmol/ml increase in ANF. Moreover, during pregnancy, the LAP-ANF relationship was significantly more sensitive because a 10-mmHg increase in LAP resulted in a 433 +/- 15 fmol/ml elevation of ANF. These data demonstrate that plasma ANF levels are more responsive to distension of the left atria than to the right. More importantly, the ANF response to left, but not right, atrial distension is enhanced by pregnancy.

Atrial dynamics, atrial natriuretic factor, tachycardia, and blood volume in anesthetized rabbits

1991 ◽  
Vol 261 (1) ◽  
pp. H22-H28 ◽  
Author(s):  
K. A. King ◽  
J. R. Ledsome
Keyword(s):  
Blood Volume ◽  
Atrial Natriuretic Factor ◽  
Left Atrial ◽  
Wall Stress ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Atrial Wall ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

The effects of tachycardia and a slow (1%/min) 20% reduction and elevation of blood volume (BV) on right atrial pressure (RAP), right atrial dimension (RAD), and plasma immunoreactive atrial natriuretic factor (IR-ANF) were examined in anesthetized rabbits. Plasma IR-ANF was significantly increased during pacing at 6 Hz in the presence of high BV but not at low BV. Mean RAP increased with expansion of BV, but this change was not associated with significant changes in IR-ANF. There were no statistically significant changes in systolic or diastolic RAD with alterations in BV or with tachycardia. Tachycardia had no effect on left atrial dimension. Diastolic right atrial wall stress (DRAS) and minute DRAS increased with a 20% increase in BV, but changes in BV did not affect systolic right atrial wall stress (SRAS) or minute SRAS. Tachycardia decreased DRAS at high BV and significantly increased SRAS and minute SRAS. The increases in SRAS and minute SRAS were greater during tachycardia at high BV, suggesting that an interaction between BV and tachycardia results in potentiation of SRAS and minute SRAS. The results suggest that systolic RAS is a significant factor in ANF release during tachycardia at high BV.

Reference sites not influenced by hydrostatic pressure for right and left atrial pressures

1964 ◽  
Vol 207 (2) ◽  
pp. 357-360 ◽  
Author(s):  
George G. Armstrong ◽  
John C. Hancock
Keyword(s):  
Hydrostatic Pressure ◽  
Reference Point ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Right Atrial ◽  
Lateral Border ◽  
Zero Reference ◽  
The Right ◽  
Made In

Simultaneous recordings of left and right atrial pressures made in dogs being rotated into all positions in space allowed the location of rotational axes where right or left atrial pressure became independent of hydrostatic pressure. Utilization of these axes as zero reference levels made possible the measurement of right or left atrial pressure without the influence of hydrostatic factors. The right zero reference point lay 62.8% of the distance from the manubrium to the xiphoid, 61.2% of the posterior to anterior thoracic diameter, and 47.7% of the greatest transverse thoracic diameter as measured from the right lateral border. The left atrial zero reference point lay 62.1% of the manubrium to xiphoid distance, 57.2% of the posterior to anterior diameter of thorax, and 53.0% of the greatest transverse thoracic diameter as measured from the right lateral border. When referred to the anatomy of the dog, these points lay in the immediate vicinity of the right and left atrioventricular valves, respectively.

Prediction of circulatory equilibrium in response to changes in stressed blood volume

2005 ◽  
Vol 289 (1) ◽  
pp. H301-H307 ◽  
Author(s):  
Kazunori Uemura ◽  
Toru Kawada ◽  
Atsunori Kamiya ◽  
Takeshi Aiba ◽  
Ichiro Hidaka ◽  
...  
Keyword(s):  
Blood Volume ◽  
Single Point ◽  
Point Estimation ◽  
Accurate Prediction ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Heart ◽  
Left And Right ◽  
Failure Conditions ◽  
The Right

Accurate prediction of cardiac output (CO), left atrial pressure (PLA), and right atrial pressure (PRA) is a prerequisite for management of patients with compromised hemodynamics. In our previous study (Uemura et al. Am J Physiol Heart Circ Physiol 286: H2376–H2385, 2004), we demonstrated a circulatory equilibrium framework, which permits the prediction of CO, PLA, and PRA once the venous return surface and integrated CO curve are known. Inasmuch as we also showed that the surface can be estimated from single-point CO, PLA, and PRA measurements, we hypothesized that a similar single-point estimation of the CO curve would enable us to predict hemodynamics. In seven dogs, we measured the PLA-CO and PRA-CO relations and derived a standardized CO curve using the logarithmic function CO = SL[ln(PLA − 2.03) + 0.80] for the left heart and CO = SR[ln(PRA − 2.13) + 1.90] for the right heart, where SL and SR represent the preload sensitivity of CO, i.e., pumping ability, of the left and right heart, respectively. To estimate the integrated CO curve in each animal, we calculated SL and SR from single-point CO, PLA, and PRA measurements. Estimated and measured CO agreed reasonably well. In another eight dogs, we altered stressed blood volume (−8 to +8 ml/kg of reference volume) under normal and heart failure conditions and predicted the hemodynamics by intersecting the surface and the CO curve thus estimated. We could predict CO [ y = 0.93 x + 6.5, r 2 = 0.96, standard error of estimate (SEE) = 7.5 ml·min−1·kg−1], PLA ( y = 0.90 x + 0.5, r 2 = 0.93, SEE = 1.4 mmHg), and PRA ( y = 0.87 x + 0.4, r 2 = 0.91, SEE = 0.4 mmHg) reasonably well. In conclusion, single-point estimation of the integrated CO curve enables accurate prediction of hemodynamics in response to extensive changes in stressed blood volume.

Sinoaortic baroreceptors and the control of blood volume in the nonhuman primate

1984 ◽  
Vol 247 (4) ◽  
pp. F539-F542
Author(s):  
K. G. Cornish ◽  
T. McCulloch ◽  
J. P. Gilmore
Keyword(s):  
Blood Pressure ◽  
Blood Volume ◽  
Left Atrial ◽  
Volume Expansion ◽  
Pressure Pulse ◽  
Urethral Catheter ◽  
Inhibitory Influence ◽  
Before And After ◽  
Human Primate

The purpose of this study was to determine the role of the aortic and carotid baroreceptors in regulating blood volume in the conscious non-human primate. Eighteen control animals were surgically instrumented to permit the recording of blood pressure, pulse rate, and left atrial pressure. After a urethral catheter was inserted into the bladder, the animals were given an intravenous infusion equal to 20% of the estimated blood volume. Renal function was determined before and after the volume expansion. Nine monkeys received the same infusion after undergoing chronic sinoaortic denervation. The denervated animals responded with a potentiated diuresis and natriuresis. The control animals excreted 24% of the infused volume and 4% of the infused salt while the sinoaortic-denervated animals excreted a volume equal to 113% of that infused and an amount of sodium equal to 46% of that infused. We conclude that high-pressure receptors exert an inhibitory influence on whatever mechanisms are involved in the renal response to acute volume expansion.

P5595Non-invasive atrial work in the differential diagnosis of pre-capillary and post-capillary pulmonary hypertension

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A E Vijiiac ◽  
S Iancovici ◽  
A Scarlatescu ◽  
A Deaconu ◽  
M Dorobantu
Keyword(s):  
Pulmonary Hypertension ◽  
Differential Diagnosis ◽  
Left Atrial ◽  
Roc Analysis ◽  
Vena Cava ◽  
Left Ventricular ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Atrial Volume ◽  
The Right

Abstract Background Right heart catheterization (RHC) is the gold standard for the diagnosis of pulmonary hypertension (PH) and for the discrimination of pre-capillary from post-capillary PH, but it is an invasive method with high costs and limited availability. While echocardiography is widely used in the evaluation of patients with PH, no algorithm has been validated to discriminate between the various forms of PH. Purpose We aimed to assess the differences in echocardiographically-derived atrial work between patients with different forms of PH. Methods We included 80 patients in our study, which were divided in two groups. The pre-capillary group consisted of 28 patients with pulmonary arterial hypertension confirmed at RHC. The post-capillary group consisted of 52 patients with PH and severe left heart disease. All patients underwent transthoracic echocardiography. Atrial work is defined as the product between atrial volume and atrial pressure; for the right atrium, we estimated atrial pressure from the inferior vena cava diameter and change with respiration; for the left atrium, we used thetransmitral E-wave/ septal mitral annular Doppler Tissue Imaging e'-wave ratio (E/e') as a surrogate for atrial pressure and we defined left atrial work as E/e' × left atrial volume. Results The mean age was 54±14 years in the pre-capillary group and 71±13 years in the post-capillary group (p<0.001). Among the patients in the post-capillary group, 36 (69%) had severe left ventricular systolic dysfunction (mean ejection fraction=23±8%) and 16 (31%) had severe aortic stenosis. The right atrial work was significantly higher in the pre-capillary group: 1089±1105 vs. 382±508 in the post-capillary group (p=0.004). Using receiver operating characteristic (ROC) analysis, a cut-off value of 289.5 provided fair discrimination (area under the curve [AUC] = 0.762) between the two groups (sensitivity=67%, specificity=67%). The left atrial work was significantly lower in the pre-capillary group: 392±206 vs. 1907±1072 in the post-capillary group (p<0.001). Using ROC analysis, a cut-off value of 764 provided excellent discrimination (AUC=0.980) between the two groups (sensitivity=95%, specificity=96%). There was a moderate positive correlation correlation between right atrial work and left atrial work in the post-capillary group (r=0.60, p<0.001), but no significant correlation in the pre-capillary group (p=0.84). Conclusion Echocardiographically-derived atrial work, both right and left, differ significantly between pre-capillary and post-capillary PH. These two simple echocardiographic parameters might guide the differential diagnosis of PH and potentially reduce the need for RHC, should they be further validated. Acknowledgement/Funding This work was supported by CREDO Project - ID: 49182, financed through the SOP IEC-A2-0.2.2.1-2013-1 cofinanced by the ERDF

Plasma vasopressin during increases and decreases in blood volume in anaesthetized dogs

1985 ◽  
Vol 63 (3) ◽  
pp. 224-229 ◽  
Author(s):  
J. R. Ledsome ◽  
N. Wilson ◽  
C. A. Courneya
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Blood Volume ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Natural Logarithm ◽  
Plasma Vasopressin ◽  
Logarithmic Relationship ◽  
Atrial Receptors

In chloralose-anaesthetized dogs, plasma vasopressin concentration was measured by radioimmunoassay during step changes in blood volume of 4 mL/kg over a range of blood volume from +20 to −12 mL/kg. Blood volume was both increased and decreased over this range. There was a logarithmic relationship between blood volume and plasma vasopressin concentration over the range of blood volume examined. There was also a logarithmic relationship between blood volume and mean left atrial pressure. Linear regression between the natural logarithm of plasma vasopressin concentration and mean arterial pressure, heart rate, and mean left atrial pressure gave the highest correlation coefficient (r = 0.94) between vasopressin and mean arterial pressure. The results support the hypothesis that there are sensitive mechanisms controlling the release of vasopressin in response to changes in blood volume. Observations were also made of changes in atrial pressure and activity of left atrial receptors during changes in blood volume over the same range. The results suggest that changes in atrial receptor activity are unlikely to be the major cause of the large increases in plasma vasopressin concentration associated with hypovolemia.

Effect of loading right atrial and ventricular receptors on stimulated AVP, ACTH, and renin secretion in awake dogs

1995 ◽  
Vol 268 (4) ◽  
pp. R1069-R1077 ◽  
Author(s):  
L. J. Andersen ◽  
J. L. Andersen ◽  
T. N. Thrasher ◽  
L. C. Keil ◽  
D. J. Ramsay
Keyword(s):  
Mean Arterial Pressure ◽  
Left Atrial ◽  
Adrenocorticotropic Hormone ◽  
Inferior Vena ◽  
Vena Cava ◽  
Plasma Renin ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Heart ◽  
The Right

The goal of this study was to test the hypothesis that increasing or decreasing the load on baroreceptors in the right heart influenced the secretion of arginine vasopressin (AVP), adrenocorticotropic hormone (ACTH), and renin during a state of sustained arterial hypotension. The hypothesis was tested in chronically instrumented conscious dogs prepared with inflatable cuffs around the pulmonary artery (PA) and the thoracic inferior vena cava (IVC). In one protocol (n = 5), mean arterial pressure was reduced 10 or 20% below control by constriction of the PA, a maneuver that caused a fall in left atrial pressure (LAP) and an increase in right atrial pressure (RAP). Plasma AVP, ACTH, atrial natriuretic peptide (ANP), and plasma renin activity (PRA) all increased (P < 0.05) in response to constriction of the PA. Reducing RAP to control by constriction of the IVC during maintained constriction of the PA had no effect on MAP, LAP, plasma AVP, ACTH, or PRA, but plasma ANP fell significantly. In a separate protocol (n = 4), constriction of the IVC was used to reduce MAP 10 or 20% below control, and this led to significant decreases in both LAP and RAP and increases in plasma AVP, ACTH, and PRA. RAP was then increased above control by constriction of the PA without altering either MAP or LAP. Raising RAP from a level that was 6.3 +/- 1.3 mmHg below control to 3.5 +/- 1.0 mmHg above control had no effect on plasma AVP, ACTH, or PRA.(ABSTRACT TRUNCATED AT 250 WORDS)

Pregnancy alters cardiac receptor afferent discharge in rats

2000 ◽  
Vol 278 (1) ◽  
pp. R149-R156 ◽  
Author(s):  
Tina Hines ◽  
Tracy M. Hodgson
Keyword(s):  
Arterial Pressure ◽  
Vagus Nerve ◽  
Low Frequency ◽  
Atrial Pressure ◽  
Single Fiber ◽  
Right Atrial ◽  
Spontaneous Discharge ◽  
Pregnant Rats ◽  
Afferent Discharge ◽  
The Right

Reflex effects of cardiac receptor (CR) stimulation are attenuated in pregnant rats. We tested whether CR afferent discharge is reduced during pregnancy by measuring single fiber activity in response to increases in right atrial pressure (RAP) in anesthetized pregnant and virgin rats with sinoaortic denervation. Single fiber activity was isolated from fine filaments of the right cervical vagus nerve. Changes in CR discharge, RAP, and arterial pressure were recorded in response to atrial saline injections (25–300 μl). Resting RAP was similar between groups, and spontaneous CR discharge was similar in pregnant rats (1.95 ± 0.21 Hz) and in low-frequency (LF) receptors in virgin rats (1.30 ± 0.2 Hz). In virgin, but not pregnant rats, a subset (24%) of CR had higher-frequency (HF) spontaneous discharge (9.91 ± 1.19 Hz). During stimulation, the level of RAP above which CR firing increased was significantly higher in pregnant rats, but CR activity was clustered into an LF discharge range. Thus gestation appears to reduce the activity of CR afferents, possibly by increasing stimulus threshold or by selective inactivation of a subset of HF discharging receptors.

Right atrial dimension-pressure relation during volume expansion is unaltered by pregnancy in the rat

2005 ◽  
Vol 288 (1) ◽  
pp. H116-H120 ◽  
Author(s):  
Tina Hines ◽  
Sarang S. Abhyankar ◽  
Jessica M. Veeh
Keyword(s):  
Arterial Pressure ◽  
Blood Volume ◽  
Right Atrium ◽  
Volume Expansion ◽  
Right Atrial ◽  
Drug Infusion ◽  
Pregnant Rats ◽  
The Right ◽  
Afferent Signaling ◽  
Initial Blood

Blood volume expands significantly during pregnancy, but afferent signals from cardiac receptors are reduced. In addition, during exogenous volume expansion, right atrial pressure (RAP) increases more for equivalent volumes in pregnant animals, implying reduced atrial compliance. To examine possible gestational alterations in atrial dimension during volume expansion, we compared the effects of volume expansion on RAP and right atrial dimension (RAD) in pregnant vs. virgin rats. Anesthetized animals were ventilated and catheterized for measurement of arterial pressure and RAP and for drug infusion. Through a parasternal incision, ultrasonic crystals were glued to the medial and lateral surfaces of the right atrium for measurement of RAD. Plasma volume and hematocrit were determined before experimentation. RAP, RAD, and arterial pressure were recorded at baseline and during progressive volume expansion (6% dextran, 60% of initial blood volume). Baseline RAP was similar in the two groups: 2.82 ± 0.40 and 2.72 ± 0.47 mmHg in pregnant and virgin rats, respectively. Basal RAD was significantly larger in pregnant than in virgin rats: 4.36 ± 0.66 vs. 3.36 ± 0.48 mm. Despite increased basal RAD in pregnant rats, the slope of the RAD-RAP relation during volume expansion was similar in the two groups. Results indicate that resting RAD is increased in pregnant rats and that the change in dimension during volume loads is similar to that in virgin rats. Thus, during pregnancy, the right atrium appears to accommodate the increased blood volume, and reduced afferent signaling most likely is due to mechanisms other than mechanical alterations of the atrium by expanded volume.

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