HEMODYNAMICS DURING THE CHRONIC STAGE OF MYOCARDIAL DAMAGE CAUSED BY ISOPROTERENOL

1964 ◽  
Vol 42 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Margaret Beznak ◽  
P. Hacker
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Myocardial Damage ◽  
Ventricular Wall ◽  
Normal Range ◽  
Chronic Stage ◽  
Histological Damage ◽  
Third Stage ◽  
The Right ◽  
Cardiac Enlargement

Cardiovascular measurements were performed in rats 3–4 days, 1 week, 2 weeks, 5–6 weeks, and 4–5 months after the subcutaneous injection of 40 mg/kg isoproterenol on two consecutive days. Up to 1 week after the injections severe histological damage of the myocardium was accompanied by cardiac enlargement and impaired function: blood pressure, cardiac output and work were in the normal range under basal conditions but the maximum cardiac output and work measured during infusion of polyvinylpyrrolidone into the right side of the heart were well below normal. During the following weeks histological repair took place and the cardiovascular parameters measured were not different from those found in normal rats. This period was followed by a third stage which occurred without further interference with the heart. It consisted of thinning of the ventricular wall and aneurysm formation. All cardiovascular values (maximum and basal as well) were below normal without development of cardiac enlargement.

IMMEDIATE HEMODYNAMIC EFFECTS OF ISOPROTERENOL

1963 ◽  
Vol 41 (1) ◽  
pp. 1949-1953 ◽  
Author(s):  
Margaret Beznák ◽  
P. Hacker
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Subcutaneous Injection ◽  
Direct Action ◽  
Peripheral Resistance ◽  
Oxygen Demand ◽  
Hemodynamic Effects ◽  
Hemodynamic Changes ◽  
Histological Damage

Subcutaneous injection of 40 mg/kg isoproterenol is followed within 2 minutes by a fall in blood pressure and peripheral resistance, by tachycardia, and by an increase in cardiac output. It seems likely that these hemodynamic changes are a consequence of a direct action of isoproterenol on the myocardium. Isoproterenol also causes a significant increase in the oxygen consumption of the rats. The increased oxygen demand of the tissues may play a role in maintaining the hemodynamic changes for periods of more than an hour after isoproterenol. Signs of histological damage in the myocardium begin to appear without affecting the function of the cardiovascular system, as measured by the tests used.

HEMODYNAMICS DURING THE ACUTE PHASE OF MYOCARDIAL DAMAGE CAUSED BY ISOPROTERENOL

1962 ◽  
Vol 40 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Margaret Beznak
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Acute Phase ◽  
Functional Capacity ◽  
Myocardial Damage ◽  
Male Rats ◽  
Histological Changes ◽  
Subcutaneous Injections ◽  
Norepinephrine Infusion ◽  
The Difference

One to three days after two consecutive subcutaneous injections of 40 mg/kg isoproterenol were given to male rats, severe histological changes occurred in the myocardium. Blood pressure, cardiac output, and work of these rats did not differ from normal. During polyvinylpyrrolidone infusion, normal rats raised their cardiac output to about three times the preinfusion value, while only a slight increase took place in the isoproterenol-treated rats. The difference was less marked during pitressin and norepinephrine infusion. It is concluded that during the acute damage of the myocardium by isoproterenol, the functional capacity of the heart is greatly reduced.

IMMEDIATE HEMODYNAMIC EFFECTS OF ISOPROTERENOL

1963 ◽  
Vol 41 (9) ◽  
pp. 1949-1953 ◽  
Author(s):  
Margaret Beznák ◽  
P. Hacker
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Subcutaneous Injection ◽  
Direct Action ◽  
Peripheral Resistance ◽  
Oxygen Demand ◽  
Hemodynamic Effects ◽  
Hemodynamic Changes ◽  
Histological Damage

Subcutaneous injection of 40 mg/kg isoproterenol is followed within 2 minutes by a fall in blood pressure and peripheral resistance, by tachycardia, and by an increase in cardiac output. It seems likely that these hemodynamic changes are a consequence of a direct action of isoproterenol on the myocardium. Isoproterenol also causes a significant increase in the oxygen consumption of the rats. The increased oxygen demand of the tissues may play a role in maintaining the hemodynamic changes for periods of more than an hour after isoproterenol. Signs of histological damage in the myocardium begin to appear without affecting the function of the cardiovascular system, as measured by the tests used.

scholarly journals Mechanical support of the pressure overloaded right ventricle: an acute feasibility study comparing low and high flow support

2015 ◽  
Vol 309 (4) ◽  
pp. H615-H624 ◽  
Author(s):  
Tom Verbelen ◽  
Jelle Verhoeven ◽  
Motohiko Goda ◽  
Daniel Burkhoff ◽  
Marion Delcroix ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Ventricular ◽  
High Flow ◽  
Low Flow ◽  
Mechanical Support ◽  
Arterial Blood ◽  
The Right

The objectives of this study were to assess the feasibility of low flow right ventricular support and to describe the hemodynamic effects of low versus high flow support in an animal model of acute right ventricular pressure overload. A Synergy Pocket Micro-pump (HeartWare International, Framingham, MA) was implanted in seven sheep. Blood was withdrawn from the right atrium to the pulmonary artery. Hemodynamics and pressure-volume loops were recorded in baseline conditions, after banding the pulmonary artery, and after ligating the right coronary artery in these banded sheep. End-organ perfusion (reflected by total cardiac output and arterial blood pressure) improved in all conditions. Intrinsic right ventricular contractility was not significantly impacted by support. Diastolic unloading of the pressure overloaded right ventricle (reflected by decreases in central venous pressure, end-diastolic pressure and volume, and ventricular capacitance) was successful, but with a concomitant and flow-dependent increase of the systolic afterload. This unloading diminished with right ventricular ischemia. Right ventricular mechanical support improves arterial blood pressure and cardiac output. It provides diastolic unloading of the right ventricle, but with a concomitant and right ventricular assist device flow-dependent increase of systolic afterload. These effects are most distinct in the pressure overloaded right ventricle without profound ischemic damage. We advocate the low flow strategy, which is potentially beneficial for the afterload sensitive right ventricle and has the advantage of avoiding excessive increases in pulmonary artery pressure when pulmonary hypertension exists. This might protect against the development of pulmonary edema and hemorrhage.

Deterioration in cardiac systolic and diastolic function late in normal human pregnancy

2009 ◽  
Vol 116 (7) ◽  
pp. 599-606 ◽  
Author(s):  
Dominica Zentner ◽  
Moira du Plessis ◽  
Shaun Brennecke ◽  
James Wong ◽  
Leeanne Grigg ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Cardiac Function ◽  
Left Ventricular Mass ◽  
Wall Stress ◽  
Left Ventricular ◽  
Doppler Imaging ◽  
P Value ◽  
Ventricular Wall ◽  
Ventricular Mass

The aim of the present study was to undertake a longitudinal study of systolic and diastolic cardiac function during normal pregnancy. At a median of 16 weeks of gestation, 100 primiparous women underwent echocardiography, including tissue Doppler imaging, determining left ventricular mass, cardiac output, systolic and diastolic velocities, and wall stress. A total of 32 were assessed again at a median of 37 weeks of gestation. Non-pregnant control estimates (n=9) were obtained by averaging four separate measures over two menstrual cycles. Initially, the pregnant women had significantly higher pulse rates than controls, associated with greater ventricular wall stress (two-tailed P value=0.015), and systolic (two-tailed P value=0.005) and diastolic (two-tailed P value=0.018) lateral wall myocardial velocities, but no differences in systolic blood pressure, left ventricular mass or cardiac output. By 37 weeks of gestation, increased blood pressure (two-tailed P value <0.001) and left ventricular mass (two-tailed P value=0.002) were associated with a significant increase in ventricular wall stress (two-tailed P value <0.001), and reductions in septal systolic (two-tailed P value=0.004) and septal and lateral early diastolic (two-tailed P value <0.001) myocardial velocities. The diastolic velocities at 37 weeks correlated inversely with maternal weight and age. In conclusion, by term pregnancy, an increase in ventricular wall stress is accompanied by a deterioration in cardiac function.

HEMODYNAMICS DURING THE ACUTE PHASE OF MYOCARDIAL DAMAGE CAUSED BY ISOPROTERENOL

1962 ◽  
Vol 40 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Margaret Beznak
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Acute Phase ◽  
Functional Capacity ◽  
Myocardial Damage ◽  
Male Rats ◽  
Histological Changes ◽  
Subcutaneous Injections ◽  
Norepinephrine Infusion ◽  
The Difference

One to three days after two consecutive subcutaneous injections of 40 mg/kg isoproterenol were given to male rats, severe histological changes occurred in the myocardium. Blood pressure, cardiac output, and work of these rats did not differ from normal. During polyvinylpyrrolidone infusion, normal rats raised their cardiac output to about three times the preinfusion value, while only a slight increase took place in the isoproterenol-treated rats. The difference was less marked during pitressin and norepinephrine infusion. It is concluded that during the acute damage of the myocardium by isoproterenol, the functional capacity of the heart is greatly reduced.

scholarly journals CARDIOVASCULAR EFFECTS OF THYROXINE TREATMENT IN NORMAL RATS

1962 ◽  
Vol 40 (12) ◽  
pp. 1647-1654 ◽  
Author(s):  
Margaret Beznák ◽  
A. Marcsán ◽  
T. Fournier
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Cardiac Hypertrophy ◽  
Metabolic Rate ◽  
Normal Values ◽  
Cardiovascular Effects ◽  
Aortic Constriction ◽  
Thyroxine Treatment ◽  
The Right

Metabolic rate, blood pressure, weight and rate of the heart, cardiac output, and work were determined at weekly intervals in groups of normal rats receiving thyroxine. The measurements were made before and during the infusion of polyvinylpyrrolidone into the right side of the heart. The maximum values of cardiac output and work obtained during infusion were considered to be an approximate measure of the strength of the heart. Cardiac output and work in thyroxine-treated rats far exceeded the normal values before as well as during infusion. The greater strength was not merely the consequence of the greater size of the heart which developed in the course of thyroxine treatment. Hearts of similar size — coming from larger normal rats or from smaller normal rats with cardiac hypertrophy due to aortic constriction — did significantly less work than the hearts of thyroxine-treated rats.

scholarly journals Variation of blood pressure between two arms among the young people of Guwahati, Assam, India

2018 ◽  
Vol 6 (3) ◽  
pp. 859
Author(s):  
Indrani Das ◽  
Bonti Bora ◽  
Raj Sarkar ◽  
Kaustuv Jyoti Bhuyan
Keyword(s):  
Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Correct Diagnosis ◽  
Age Group ◽  
Normal Range ◽  
Treatment Of Hypertension ◽  
The Subject ◽  
The Mean ◽  
The Right ◽  
Mercury Sphygmomanometer

Background: Aim and objective of the study was to determine whether a difference in systolic and diastolic blood pressure reading exists in between arms. To establish the mean and normal range of difference in simultaneous systolic and diastolic blood pressure measurements between the right and left arm. It is unclear to what extent inter-arm blood pressure (BP) differences may be present in younger people so that they can take precaution in relation with age.Methods: 51 male and 51 female subjects were selected randomly in age group of 18 -20 yrs. A normal mercury sphygmomanometer was used employing Korotkoff I and V. 3 readings were taken sequentially for each arm using a standard mercury sphygmomanometer with the subject sitting after resting for 10 min.Results: Mean ± SD inter-arm differences in Systolic blood pressure were 4.784 ± 6.338 mmHg in males and 2.314 ± 5.159 mmHg in females while Diastolic blood pressure were 3.451 ± 5.471 mmHg in males and 1.059 ± 5.112 mmHg in females.Conclusions: The frequency of significant inter-arm systolic and diastolic blood pressure differences suggests that the blood pressure should be taken in both arms at the initial consultation. At subsequent visits, the arm in which measurements are taken should be recorded in the case notes. The higher of the two readings should be used to guide further management decisions. The accurate assessment of blood pressure (BP) is vital for the correct diagnosis and treatment of hypertension.

Effect of growth hormone and thyroxin on cardiovascular system of hypophysectomized rats

1963 ◽  
Vol 204 (2) ◽  
pp. 279-283 ◽  
Author(s):  
Margaret Beznak
Keyword(s):  
Blood Pressure ◽  
Growth Hormone ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiovascular System ◽  
Normal Function ◽  
Normal Response ◽  
Cardiovascular Parameters ◽  
Hypophysectomized Rats ◽  
The Right

Growth hormone, thyroxin, or growth hormone and thyroxin were given for a period of 4 weeks to rats hypophysectomized 2–3 months previously. The effect of these treatments on blood pressure, weight and rate of the heart, cardiac output, and work was measured under basal conditions and during acute loading (infusion of polyvinylpyrrolidone into the right side of the heart) as well as during chronic loading (constriction of the aorta). The changes in cardiovascular parameters in the basal state due to hypophysectomy could all be reversed by thyroxin treatment. Thyroxin alone was inadequate in restoring the response of the hearts to either acute or chronic loading. Growth hormone in combination with thyroxin could restore or even exaggerate the normal response to both chronic and acute loading as well as maintain the basal parameters. Growth hormone itself had comparatively little effect; it caused some increase in the weight of the heart and stroke volume. It is concluded that both thyroxin and growth hormone are necessary for the normal function of the cardiovascular system.

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