Factors Affecting Diastolic Blood Pressures in the Systemic and Pulmocutaneous Arches of Anuran Amphibia

1972 ◽  
Vol 57 (3) ◽  
pp. 789-803
Author(s):  
DAVID R. JONES ◽  
GRAHAM SHELTON
Keyword(s):  
Diastolic Pressure ◽  
Arterial Compliance ◽  
Peripheral Resistance ◽  
Systolic Pressure ◽  
Lung Ventilation ◽  
Factors Affecting ◽  
Spiral Valve ◽  
Prolonged Apnoea ◽  
Pressure Pulses ◽  
Blood Pressures

1. During rhythmic lung ventilation systolic blood pressures in the pulmocutaneous and systemic arches were more or less the same although diastolic pressures in the former were some 3-4 cm H2O lower than in the latter. During prolonged apnoea (20-35 min) the pulse pressures became identical. Venous pressures in both lung and body circuits were little affected by these procedures. 2. Raising or reducing systolic pressure by application of drugs to the exposed ventricle caused no change in the relationships of the pressure pulses in the systemic and pulmocutaneous arches. 3. Removal of the conus arteriosus and spiral valve caused a significant reduction in diastolic pressure in the systemic but not in the pulmocutaneous arch. 4. After conus removal differences in diastolic pressures in the systemic and pulmocutaneous arches were only recorded when valves at the apex of the conus were functional. 5. Bilateral occlusion of both systemic arches produced a greater increase in systolic blood pressure in the systemic and pulmocutaneous arches than bilateral occlusion of the pulmocutaneous arches, although pressure changes following the latter were more variable. 6. Blood flow in the pulmocutaneous arch was extremely variable, lowest stroke flows being recorded when the pressure pulses in the systemic and pulmocutaneous arches were identical. 7. The role of the conus arteriosus, spiral valve, arterial compliance and peripheral resistance in maintenance of diastolic pressures in the systemic and pulmocutaneous arches is discussed.

Estimation of Forearm Arterial Compliance in Essential Hypertension: A Preliminary Report

1982 ◽  
Vol 63 (s8) ◽  
pp. 87s-88s ◽  
Author(s):  
A. CH. Simon ◽  
J. A. Levenson ◽  
S. P. Laurent ◽  
M. E. Safar
Keyword(s):  
Blood Flow ◽  
Essential Hypertension ◽  
Brachial Artery ◽  
Diastolic Pressure ◽  
Arterial Compliance ◽  
Normal Subjects ◽  
Arterial System ◽  
Flow Measurements ◽  
Blood Pressures ◽  
Blood Flow Measurements

1. Simultaneous brachial artery pressure and blood flow measurements were made in 21 men, including six normal subjects and 15 patients with essential hypertension of the same age and diastolic pressure at the time of investigation. 2. Blood flow was evaluated by means of a pulsed Doppler device with a double transducer probe, enabling a precise evaluation of the calibre of the brachial artery. From analysis of the pressure-flow curves during diastole, forearm arterial compliance was estimated by using an original first-order model of the forearm arterial system. 3. Forearm arterial compliance was significantly decreased in hypertensive subjects. 4. Since patients and hypertensive subjects had similar blood pressures, the results indicate that the reduced forearm compliance was independent of blood pressure per se but may reflect in hypertensive subjects adaptive changes in the walls of peripheral large arteries.

Normalized input impedance and arterial decay time over heart period are independent of animal size

1991 ◽  
Vol 261 (1) ◽  
pp. R126-R133 ◽  
Author(s):  
N. Westerhof ◽  
G. Elzinga
Keyword(s):  
Heart Rate ◽  
Decay Time ◽  
Input Impedance ◽  
Diastolic Pressure ◽  
Arterial Compliance ◽  
Characteristic Impedance ◽  
Peripheral Resistance ◽  
Arterial System ◽  
Heart Period ◽  
Arterial Tree

The arterial system of mammals in the weight range from 0.6 to 70 kg is characterized by the three-element windkessel, a succinct representation of the arterial tree consisting of the parameters peripheral resistance (Rp), total arterial compliance (C), and aortic characteristic impedance (Zc). The values of these parameters in resting conditions are related to body mass (M). The time constant, or decay time (tau), of the arterial system (defining rate of decay of aortic pressure in diastole), the product of Rp and C, is also evaluated. The dependencies of the heart period (T, inverse of heart rate), and durations of ejection (Ts) and of diastole (Td) in resting conditions are also determined as a function of M. It is found that Rp = Rp0M-0.93; Zc = Zc0M-0.97; and C = C0M+1.23, where Rp0, Zc0, and C0 are proportionality constants. Zc is thus a constant fraction of Rp in all mammals. tau is related to M as tau = tau 0M+0.29; T and Td are related to M as T = T0M+0.27 and Td = Td0M+0.30, where tau 0, T0, and Td0 are proportionality constants. The duration of diastole is thus a constant fraction of T, and the ratios T/tau and Td/tau are independent of M. The findings indicate that arterial input impedance, normalized to aortic Zc and plotted as a function of frequency normalized to heart rate, is similar for all mammals. The finding that the ratio Td/tau is the same in mammals (and Ts/T and stroke volume/M are constant) explains the constancy of pulse pressure (systolic minus diastolic pressure).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Variation in carotid-femoral pulse wave velocity, augmentation pressure and augmentation index during different phases of menstrual cycle

2018 ◽  
Vol 2 (3) ◽  
pp. 27-32 ◽  
Author(s):  
Nudrath Kahkashan ◽  
Mehnaaz Sameera Arifuddin ◽  
Mohammed Abdul Hannan Hazari ◽  
Safia Sultana ◽  
Farah Fatima ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Menstrual Cycle ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Pulse Wave ◽  
Diastolic Pressure ◽  
Augmentation Index ◽  
Arterial Compliance ◽  
Systolic Pressure ◽  
Augmentation Pressure

Physiological variation of estrogen and progesterone during menstrual cycle is well known. They not only have an effect on blood pressure control, but also seem to have a role in regulating arterial compliance. This study was done to find out whether there are any changes in central arterial parameters during different phases of menstrual cycle. Thirty female subjects in the age group of 18-22 years with normal, regular menstrual cycles participated in this prospective observational study at our teaching hospital. Anthropometric parameters were recorded. Blood pressure in all 4 limbs was recorded using cardiovascular risk analyzer-Periscope™ on Day 3rd to 5th (follicular phase), Day 12th to 14th (ovulation phase), Day 22nd to 24th (luteal phase) of their menstrual cycle. We collected blood samples during these three phases for estimation of estradiol and progesterone by ELISA technique. Analysis of variance and correlation statistics were done using SPSS 17.0 statistical software. No significant statistical changes were observed in systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, aortic systolic pressure, aortic diastolic pressure, aortic augmentation pressure, aortic index and pulse wave velocity during the three recorded phases of the menstrual cycle. There are many studies which correlate changes in peripheral artery blood pressure with different phases of menstrual cycle. But there is scarcity in data available which correlates central arterial pressures and arterial stiffness with natural hormonal variations in different phases of menstrual cycle. However, our results show that although there are subtle changes in blood pressure parameters along with estrogen and progesterone levels throughout the menstrual cycle, yet these were not statistically significant.

Indirect blood pressure determination by Doppler technique in renal hypertensive cats

1979 ◽  
Vol 237 (6) ◽  
pp. H720-H723 ◽  
Author(s):  
L. R. Klevans ◽  
G. Hirkaler ◽  
J. L. Kovacs
Keyword(s):  
Blood Pressure ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Pressure Measurements ◽  
Blood Pressure Determination ◽  
Monitoring Period ◽  
Direct Pressure ◽  
Blood Pressures ◽  
Pressure Changes ◽  
Indirect Blood Pressure

The Doppler ultrasonic recording technique was used to measure systolic and diastolic blood pressures indirectly in renal hypertensive cats. The accuracy of the method was evaluated by comparing indirect blood pressures from one leg of a cat with direct pressure measurements from the other leg. A linear relationship existed between indirect and direct systolic and diastolic pressures. The consistency of the method was assessed by measuring blood pressure during a 5-h monitoring period in normotensive and renal hypertensive cats. No significant variation occurred over this period. The sensitivity of the method to blood pressure changes was determined also. A significant reduction in systolic and diastolic pressure induced by hydralazine, 10 mg/kg po, was recorded during a 5-h monitoring period. The development of renovascular hypertension was followed for approximately 70 days. Systolic pressure rose in a logarithmic fashion from 160 to a maximum of 240 mmHg. It was concluded that the Doppler ultrasonic technique is a simple and reliable method for recording indirect blood pressure acutely and chronically in conscious unrestrained cats.

Diurnal patterns of hemodynamic performance in nonhuman primates

1987 ◽  
Vol 253 (5) ◽  
pp. R779-R785
Author(s):  
B. T. Engel ◽  
M. I. Talan
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Diastolic Pressure ◽  
Peripheral Resistance ◽  
Diurnal Patterns ◽  
Arterial Blood ◽  
Blood Pressures ◽  
Hemodynamic Performance ◽  
Lower Cardiac Output

Heart rate, stroke volume, and intra-arterial blood pressures were monitored continuously in each of four monkeys for 18 consecutive hours, 5 days/wk, for several weeks. Mean heart rate, stroke volume, cardiac output, systolic and diastolic pressure, and total peripheral resistance were calculated each minute, and these averages were analyzed further to yield hourly means and intercorrelations. The main findings from the analyses of mean levels were that cardiac output fell throughout the night and that peripheral resistance rose during the same interval so that arterial pressure fell only slightly; the highest levels of peripheral resistance and lowest levels of cardiac output were recorded between 0500 and 0700. Furthermore, the levels of these responses during the remainder of the morning were higher (peripheral resistance) and lower (cardiac output) than those recorded in the evening.

Blood pressure and hemodynamic responses after exercise in older hypertensives

1987 ◽  
Vol 63 (1) ◽  
pp. 270-276 ◽  
Author(s):  
J. M. Hagberg ◽  
S. J. Montain ◽  
W. H. Martin
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Essential Hypertension ◽  
Stroke Volume ◽  
Diastolic Pressure ◽  
Peripheral Resistance ◽  
Systolic Pressure ◽  
Vo2 Max ◽  
Lower Blood ◽  
Single Bout

Recently, systolic and diastolic blood pressure have been reported to be significantly lower for several hours after exercise than when measured at rest before exercise in individuals with essential hypertension. We sought to determine the hemodynamic mechanism underlying this reduction in blood pressure. Twenty-four men and women 60–69 yr of age with persistent essential hypertension completed one of the following protocols: exercise at 50% of maximum O2 consumption (VO2 max) followed by 1 h of recovery, exercise at 70% of VO2 max followed by 3 h of recovery, or a 4-h control study. Systolic pressure was significantly lower during recovery after both intensities of exercise, but diastolic pressure was unchanged. The lower blood pressure was primarily due to a reduction in cardiac output, since total peripheral resistance was increased throughout both recovery periods. Cardiac output was reduced in recovery because of a reduction in stroke volume. Heart rate was above, or no different from, that at rest before exercise. Changes in plasma volume could not entirely account for the reduction in stroke volume. Therefore, other mechanisms altering venous return and/or myocardial contractility appear to be responsible for the reduction in systolic blood pressure evident after a single bout of submaximal exercise in individuals with essential hypertension.

Abstract 284: A Pilot Study Comparing Two Ambulatory Blood Pressure Monitors Worn at the Same Time

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Radhakrishna R Kallem ◽  
Kevin Meyers ◽  
Deirdre Sawinski ◽  
Raymond R Townsend
Keyword(s):  
Blood Pressure ◽  
Ambulatory Blood Pressure ◽  
Diastolic Pressure ◽  
Blood Pressure Monitoring ◽  
Demographic Data ◽  
Systolic Pressure ◽  
University Of Pennsylvania ◽  
Public Health Importance ◽  
Blood Pressures ◽  
The University

Introduction Ambulatory blood pressure monitoring (ABPM) has been proposed as the most effective way to characterize a person’s BP profile. However, there are very limited data in the literature comparing two simultaneously worn ABPM devices. Therefore, we compared an eight hour daytime simultaneous ABPM using two monitors (Mobil-O-Graph [I.E.M., Stolberg, Germany] and Spacelabs 90207 [Spacelabs Medical, Issequah, WA]). Methods Simultaneous BP and heart rate data were measured on 13 adult volunteers at the University of Pennsylvania using the two monitors over an 8 hour period. Other demographic data were also collected. Standard seated BPs were obtained in triplicate at the beginning and end of the 8 hour monitoring period using an Accutor (Datascope, Mahwah, NJ) device. Three blood pressures were obtained at 1 minute intervals, recorded and averaged for each arm using the Accutor device. Results The data show high concordance of measured mean arterial pressures (Mobil-O-Graph 101.4 [SEM-2.0] mmHg, Spacelabs 100.6 [SEM-2.4] mmHg) and heart rates (Mobil-O-Graph measuring 82.4 [ SEM- 4.1] beats/minute, Spacelabs 81.7 [4.0] beats/minute) between the monitors. Spacelabs measured a 10 mmHg higher systolic pressure (p=0.0016) and a non-statistically significant, but numerically higher (2.8 mmHg) diastolic pressure (Figure 1). Conclusion The systolic BP difference between the two devices has public health importance. These differences if confirmed in larger cohorts, ABPM manufacturers should consider developing a normative database to help practitioners interpret ABPM data obtained with their device.

INDIRECT ESTIMATION OF SYSTOLIC AND DIASTOLIC BLOOD PRESSURE IN THE NEWBORN

PEDIATRICS ◽  
1972 ◽  
Vol 50 (3) ◽  
pp. 387-394
Author(s):  
Colin H. M. Walker ◽  
Phillip J. West ◽  
Sanford L. Simons ◽  
Anthony R. Whytock
Keyword(s):  
Blood Pressure ◽  
Diastolic Pressure ◽  
Blood Pressure Monitoring ◽  
Systolic Pressure ◽  
Correlation Coefficients ◽  
Mean Value ◽  
Arithmetic Mean ◽  
Pressure Monitoring ◽  
Blood Pressures ◽  
The Mean

An impedance plethysmographic method for measuring systolic and diastolic blood pressures in small infants using standard electro-cardiogram recorders has been studied. The overall 95% confidence limit of the mean of five estimations was found to be ±3.74 mm Hg for the systolic and ±3.72 mm Hg for the diastolic value. Comparing this method with intra-arterial measurements gave correlation coefficients (r) of 0.95 (bias 10.09 mm Hg) for systolic pressure and 0.89 (Bias 10.09 mm Hg) for diastolic pressure. Values for the comparison with auscultation were 0.98 (bias 19.29 mm Hg) systolic and 0.86 (bias 10.17 mm Hg) diastolic, and for the comparison of the arithmetic mean value with the flush method 0.84 (bias 30.17 mm Hg). These results reveal a good correlation with the intra-arterial measurements and indicate that this technique can be used for the periodic or continuous blood pressure monitoring of infants.

Ventricular changes associated with sympathetic augmentation of cardiovascular pressure pulses

1959 ◽  
Vol 196 (4) ◽  
pp. 731-734 ◽  
Author(s):  
Albert F. Kelso ◽  
Walter C. Randall
Keyword(s):  
Venous Return ◽  
Diastolic Pressure ◽  
Sympathetic Innervation ◽  
Peripheral Resistance ◽  
Systolic Volume ◽  
Systolic Ejection ◽  
End Diastolic Volume ◽  
Pressure Pulses ◽  
Arterial Pulses ◽  
The Right

Electrical excitation of the sympathetic innervation of the heart elicits marked increase in force of contraction of both ventricles which in turn produce augmented arterial pressure pulses. These pulses are characterized by a shortened isometric contraction period, a steeper rise in the systolic ejection phase, and a relatively greater rise in systolic than in diastolic pressure. Cardiometer tracings reveal an increase in both the rate and volume of systolic ejection, smaller end-systolic volume, with no significant change in end-diastolic volume. Stimulation during isovolumetric conditions in the ventricles reveals that such augmentation is primarily dependent upon changes in contraction of the myocardium and not upon alterations in peripheral resistance or in initial distention of the ventricles. Augmentation of systemic arterial pulses is immediately sustained by appropriate adjustments in venous return from the pulmonary vascular bed. Prolonged augmentation demands similar adjustments in venous return to the right heart and the pulmonary bed.

An evaluation of large arteries compliance in man

1979 ◽  
Vol 237 (5) ◽  
pp. H550-H554 ◽  
Author(s):  
A. C. Simon ◽  
M. E. Safar ◽  
J. A. Levenson ◽  
G. M. London ◽  
B. I. Levy ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Vascular System ◽  
Diastolic Pressure ◽  
Arterial Compliance ◽  
Peripheral Resistance ◽  
Normal Subjects ◽  
K Value ◽  
Hypertensive Patients ◽  
Large Arteries ◽  
The Relationship

Cardiac output, blood pressure, and the characteristics of diastolic pressure decay were studied in 12 normal subjects and 23 sustained hypertensive patients of the same age. In normal subjects and in hypertensives, analysis of the diastolic decay showed that i) the form of the decay approximated a simple monoexponential curve during the last two-thirds of the diastolic segment, and ii) the time constant (t) of the curve was positively correlated with the total peripheral resistance (TPR), with an intercept of nearly zero. The validity of the relationship t = K x TPR was demonstrated both in groups of patients and also in individuals. Using a simple model for the vascular system, the K value was identified as the large arteries compliance and could thus be calculated in each individual. The values of arterial compliance was 1.26 +/- 0.04 ml.mmHg-1.m-2 in normal subjects and was significantly reduced in hypertensive patients (0.88 +/- 0.02 ml.mmHg=1.m-2,. P less than 0.001).

Sign in / Sign up

Export Citation Format

Share Document