Cardiovascular Design after ‘Reversal’ of Long-Standing Renal Hypertension in Rats

1979 ◽  
Vol 57 (s5) ◽  
pp. 19s-21s ◽  
Author(s):  
Y. Lundgren ◽  
Lilian Weiss
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Renal Artery ◽  
Renal Hypertension ◽  
Left Ventricular ◽  
Resistance Vessels ◽  
Mean Pressure ◽  
The Mean ◽  
Normotensive Control

1. After 4–5 months of renal hypertension in rats renal artery ‘declipping’ was performed. Eight weeks afterwards paired hindquarter perfusions were performed on the declipped rats and normotensive control rats, exploring the relationships between mean arterial pressure and flow, from maximal vasodilatation to maximal vasoconstriction, induced by graded noradrenaline infusions. Left ventricular weights were measured. 2. Declipping caused a fall in mean arterial pressure from 180 to 135 mmHg, though still after 8 weeks the mean pressure was 19% higher than in normotensive control rats. 3. All parameters reflecting design and reactivity of the resistance vessels and left ventricular weight decreased significantly, but not as much as mean arterial pressure, and were still significantly increased compared with those of control rats. 4. Thus neither mean arterial pressure nor cardiovascular design was normalized 8 weeks after ‘reversal’ of long-standing renal hypertension, in contrast to short-standing renal hypertension where both are completely normalized 3 weeks after declipping.

scholarly journals Mean Blood Pressure and Velocity for Calculation of Ventricular Systolic Work

1998 ◽  
Vol 41 (1) ◽  
pp. 27-28
Author(s):  
Milan Valach
Keyword(s):  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Diastolic Pressure ◽  
Weighted Average ◽  
Average Pressure ◽  
Mean Pressure ◽  
The Mean ◽  
Definition Of ◽  
Ejection Phase

In physiology, the mean arterial pressure is defined as an average pressure during one or several cardiac cycles. When calculus is not used, the mean pressure is approximately calculated as the diastolic pressure plus one third of the pulse pressure. In this article it is demonstrated that, when ventricular systolic work is concerned, the above definition of mean pressure must be replaced by a weighted average during the ejection phase of the systole. This gives a formula, by which a much higher estimate of the mean pressure is obtained.

Cardiopulmonary bypass support for treatment of left ventricular failure following coronary artery bypass grafting: the effects on epicardial microflow and graft flow

Perfusion ◽  
1996 ◽  
Vol 11 (5) ◽  
pp. 407-414
Author(s):  
Yijiang Chen ◽  
Bo Liu ◽  
Ali Belboul
Keyword(s):  
Heart Failure ◽  
Cardiopulmonary Bypass ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Artery Bypass ◽  
Left Ventricular ◽  
Graft Flow ◽  
Group A ◽  
The Mean ◽  
Group B

The relationship between graft blood flow, epicardial microflow and mean arterial pressure were studied to evaluate the use of repeated cardiopulmonary bypass (CPB) support for intraoperative heart failure following aorto-coronary bypass surgery. Ten patients with unstable angina and suffering from intraoperative heart failure (group A) were compared to 22 patients with stable angina (group B). In group A, during heart failure, the mean arterial pressure fell by 41 % (29.9 ± 6.8 mmHg, p < 0.01), graft flow (GF) by 67% (9.2 ± 2.6 ml/min, p < 0.01) and epicardial microflow by 64% (19 ± 4 AU, p < 0.01). After 15-56 min of assisted CPB support, the epicardial microflow and GF were partially restored. There were significant correlations between GF, epicardial microflow and CPB time. In group B, after protamine infusion, the epicardial microflow and GF were significantly greater than group A values (66 ± 14 AU, p < 0.001 and 29 ± 9 ml/min, p < 0.001, respectively). It is concluded that the use of temporary assisted CPB support to treat intraoperative heart failure allows the recovery of the myocardium and thereby restores the mean arterial pressure. The recovery of GF and epicardial flow occurred to a lesser extent. CPB support appeared to be suitable for about 60 min, probably because of increasing disturbance to the GF and the epicardial microcirculation.

Hyperinflation-induced cardiorespiratory failure in rats

2009 ◽  
Vol 107 (1) ◽  
pp. 275-282 ◽  
Author(s):  
Jeremy A. Simpson ◽  
Keith R. Brunt ◽  
Christine P. Collier ◽  
Steve Iscoe
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Lung Volume ◽  
Troponin T ◽  
Respiratory Acidosis ◽  
Left Ventricular ◽  
Cardiovascular Failure ◽  
Cardiorespiratory Failure ◽  
Arterial Hypoxemia ◽  
Ventricular Afterload

We previously showed that severe inspiratory resistive loads cause acute (<1 h) cardiorespiratory failure characterized by arterial hypotension, multifocal myocardial infarcts, and diaphragmatic fatigue. The mechanisms responsible for cardiovascular failure are unknown, but one factor may be the increased ventricular afterload caused by the large negative intrathoracic pressures generated when breathing against an inspiratory load. Because expiratory threshold loads increase intrathoracic pressure and decrease left ventricular afterload, we hypothesized that anesthetized rats forced to breathe against such a load would experience only diaphragmatic failure. Loading approximately doubled end-expiratory lung volume, halved respiratory frequency, and caused arterial hypoxemia and hypercapnia, respiratory acidosis, and increased inspiratory drive. Although hyperinflation immediately reduced the diaphragm's mechanical advantage, fatigue did not occur until near load termination. Mean arterial pressure progressively fell, becoming significant (cardiovascular failure) midway through loading despite tachycardia. Loading was terminated (endurance 125 ± 43 min; range 82–206 min) when mean arterial pressure dropped below 50 mmHg. Blood samples taken immediately after load termination revealed hypoglycemia, hyperkalemia, and cardiac troponin T, the last indicating myocardial injury that was, according to histology, mainly in the right ventricle. This damage probably reflects a combination of decreased O2 delivery (decreased venous return and arterial hypoxemia) and greater afterload due to hyperinflation-induced increase in pulmonary vascular resistance. Thus, in rats breathing at an increased end-expiratory lung volume, cardiorespiratory, not just respiratory, failure still occurred. Right heart injury and dysfunction may contribute to the increased morbidity and mortality associated with acute exacerbations of obstructive airway disease.

scholarly journals Correlation between Calcium Phosphorus Product and Mean Arterial Pressure among Hemodialysis Patients with End Stage Renal Disease

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Muhammad Nadeem ◽  
Mansoor Abbas Qaisar ◽  
Ali Hassan Al Hakami ◽  
Fateh Sher Chattah ◽  
Muhammad Muzammil ◽  
...  
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Renal Disease ◽  
End Stage Renal Disease ◽  
Hemodialysis Patients ◽  
Age Group ◽  
Calcium Phosphorus ◽  
The Mean ◽  
Stage Renal Disease ◽  
End Stage

Background: The mean arterial pressure serves as an expression of blood pressure in patients on chronic hemodialysis. Serum calcium phosphorus product is considered as a risk factor of vascular calcification that is associated with hypertension in the patients of end stage renal disease. The literature regarding this relationship is inconsistent therefore this study is designed to determine the correlation between calcium phosphorus product and mean arterial pressure among hemodialysis patients with end stage renal disease. Methods: A total of 110 patients of end stage renal disease on hemodialysis for at least one year, 20 to 60 years of age were included. Patients with primary or tertiary hyperparathyroidism, peripheral vascular disease, malignancy, hypertension secondary to any cause other than kidney disease were excluded. Mean arterial pressure was calculated according to the standard protocol in lying position. Blood samples for estimation of serum calcium and phosphorous were taken and was sent immediately to the laboratory for serum analysis. Results: Mean age was 44.17 ± 10.94 years. Mean calcium phosphorous product was 46.71 ± 7.36 mg/dl and mean arterial pressure was 103.61 ± 12.77 mmHg. The values of Pearson correlation co-efficient (r) were 0.863 for age group 20 to 40 years and 0.589 for age group 41 to 60 years. This strong positive correlation means that high calcium phosphorous product goes with high mean arterial pressure (and vice versa) for both the age groups. Conclusion: A strong positive relationship exists between the mean arterial pressure and calcium phosphorous product and is independent of patients’ age.

scholarly journals Hubungan Mean Arterial Pressure (MAP) Dengan Preeklamsia Pada Ibu Hamil Di Puskesmas Bontobangun Kabupaten Bulukumba

2020 ◽  
Vol 5 (2) ◽  
pp. 138-145
Author(s):  
Ely Kurniati ◽  
Rusnawati
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Pregnant Women ◽  
Sampling Method ◽  
Blood Pressure Measurement ◽  
Test Results ◽  
Historical Cohort ◽  
Measurement Results ◽  
History Of ◽  
The Mean

Preeclampsia complicates 4-7% of pregnancies and remains the leading cause of maternal and fetal morbidity and mortality worldwide. Despite improvements in health care over the last decade, preeclampsia remains the second most common cause of maternal mortality in Indonesia. This study aims to determine whether the mean arterial pressure (MAP) is related to the incidence of preeclampsia in pregnant women at the Bontobangun Puskesmas, Bulukumba district for the period 2018 to 2019. This research uses a descriptive-analytic approach with Historical Cohort Studies, namely by looking at the cohort book of the history of blood pressure measurement results for pregnant women at the Bontobangun Public Health Center, Bulukumba Regency for the period 2018 to 2019. Determining the sample using the sampling method taken by purposive sampling. 31 samples of pregnant women who experienced preeclampsia and 31 controls were pregnant women with normal conditions who had certain criteria (matching) with the sample. The results explained that from the paired T-test results, the value of α> 0.037 so that it is said that there is a relationship between mean artery pressure (MAP) and the incidence of preeclampsia in pregnant women at Bontobangun puskesmas for the period 2018-2019.

scholarly journals The Use of Biochemical and Biophysical Markers in Early Screening for Preeclampsia in Mongolia

2018 ◽  
Vol 6 (3) ◽  
pp. 57
Author(s):  
Urjindelger Tserensambuu ◽  
Ariunbold Chuluun-Erdene ◽  
Munkhtsetseg Janlav ◽  
Erkhembaatar Tudevdorj
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Pulsatility Index ◽  
Uterine Artery ◽  
Maternal Serum ◽  
Operating Characteristics ◽  
Early Screening ◽  
Roc Curve Analysis ◽  
Detection Rates ◽  
The Mean

Preeclampsia (PE) is a major cause of maternal and perinatal morbidity and mortality, particularly in developing countries. In Mongolia, preeclampsia and eclampsia have occurred among pregnancy complications at a rate of 25% in recent years. Recent studies in the literature have screened for preeclampsia by combining maternal factors with biomarkers. This study was conducted using prospective cohort research including 393 singleton pregnancies at 11–13+6 weeks. Maternal plasmas pregnancy-associated plasma protein-A (PAPP-A) and maternal serum placental growth factor (PlGF) were measured using Perkin Elmer time-resolved fluoroimmunoassay (DELFIA) kits, and the measurement of mean arterial pressure (MAP) was performed by automated devices and the uterine artery pulsatility index was measured by Doppler ultrasound. In the study population, there were 16.7% showing complicated preeclampsia. The receiver-operating characteristics (ROC) curve analysis showed a sensitivity of 71.21%, and a specificity of 75.54% when the mean arterial pressure cut-off was 89.5 mm; while a sensitivity of 33.36% and specificity of 77.68% were observed when the uterine artery mean pulsatility index (mPI) cut-off was 2.34; a sensitivity of 79.66% and specificity of 44.04% were observed when the PAPP-A cut-off was 529.1 mU/L; and a sensitivity of 74.58% and specificity of 46.6% were observed when the PlGF cut-off was 39.87 pg/mL. The detection rates following the combination of markers with the maternal history were as follows: 62.7% with mean arterial pressure, 69.5–82.9% with two markers 86.5% with three markers and 91.4% with four markers. In conclusion, the mean arterial pressure was highly sensitive and demonstrated its easy usage and cost-effectiveness as a predictive marker for the early screening of preeclampsia from other biomarkers.

Cardiovascular reflexes during abdominal ischemia in cats

1994 ◽  
Vol 267 (1) ◽  
pp. R97-R106 ◽  
Author(s):  
H. S. Huang ◽  
J. C. Longhurst
Keyword(s):  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Femoral Vein ◽  
Venous Pressure ◽  
Vena Cava ◽  
Left Ventricular ◽  
Mesenteric Arteries ◽  
Cardiovascular Reflexes ◽  
Group 3

The cardiovascular effects of regional abdominal ischemia and reperfusion were studied in cats anesthetized with alpha-chloralose. In group 1 (n = 9), central venous pressure was kept constant by a servo-controller while the celiac and superior mesenteric arteries were occluded by loop snares for 10 min. In group 2 (n = 9), a constant-perfusion circuit to the celiac and superior mesenteric arteries that could divert flow to the femoral vein was used to induce abdominal ischemia. In group 3 (n = 7), venous return from the inferior vena cava was controlled, and a constant-perfusion circuit was used to induce abdominal ischemia. Abdominal ischemia significantly (P < 0.05) increased portal venous blood lactate from 4.3 +/- 0.6 to 6.0 +/- 0.6 mM in group 3. The early increases in blood pressure caused by passive volume shifts in groups 1 and 2 were abolished in group 3. The late, i.e., 10 min, response to abdominal ischemia consisted of significant (P < 0.05) increases in mean arterial pressure (29 +/- 7, 24 +/- 7, and 33 +/- 8 mmHg in groups 1, 2, and 3, respectively). Abdominal ischemia also significantly (P < 0.05) increased the first derivative of left ventricular pressure at 40 mmHg developed pressure from 4,355 +/- 377 to 4,839 +/- 407 mmHg/s in group 3. Celiac and superior mesenteric ganglionectomy abolished the late but not the early hemodynamic changes. Ganglionectomy also significantly (P < 0.05) enhanced the decrease in mean arterial pressure during reperfusion in all groups. We conclude that the pressor and contractile responses during 10 min of abdominal ischemia and the relative maintenance of blood pressure during reperfusion after ischemia are reflex in nature.

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