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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemodynamic effects of isoproterenol, dopamine, and epinephrine were studied before and after acute beta-adrenergic blockade in 16 open-chest, anesthetized mongrel dogs. Beta blockade was induced with 1 mg. per kilogram of intravenous propranolol. Cardiac output measurements were obtained by thermal dilution, and pressure recordings were obtained in the right ventricle, pulmonary artery, left atrium, left ventricle, and aorta. Derived parameters included stroke volume, pulmonary and systemic vascular resistances, and peak left ventricular dP/dt. In the presence of propranolol, epinephrine became a lethal drug in large doses and did not increase cardiac output in standard doses. Dopamine, in 25 to 50 mcg. per kilogram per minute doses, increased arterial pressure and systemic resistance; cardiac output was diminished compared with dopamine, 10 mcg. per kilogram per minute, prior to propranolol, as a result of increased resistance and decreased LV contractility. Isoproterenol, 0.6 to 0.9 mcg. per kilogram per minute, 15 to 20 times standard dosages, had moderately positive inotropic effects and increased cardiac output. Left ventricular systolic pressure with isoproterenol after propranolol was reduced when compared with effects of smaller doses prior to propranolol. These observations suggest that none of the catecholamines studied would be optimal for circulatory support in heart failure in the presence of propranolol. The present results define a pharmacologic basis for design of appropriate drug combinations for circulatory support in beta-blocked animals.
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PMID:Pharmacologic antagonism of beta-adrenergic blockade in dogs. I. Hemodynamic effects of isoproterenol, dopamine, and epinephrine in acute propranolol administration. 3 98

Dopamine (DA), serotonin (5-HT), tryptophan (TRP), 5-hydroxyindole acetic acid (5-HIAA), and GABA were assayed spectrofluorometrically in various regions of 16 human post-mortem brains with acute and old cerebral infarction. In both recent and older strokes a total depletion of DA and 5-HT in the necrotic tissue was associated with mild reduction of these compounds in remote non-ischemic areas of the injured, and less of the contralateral cerebral hemispheres. 5-HIAA was significantly reduced in acute ischemic necrosis, while the perifocal edema zone showed considerable accumulation of both 5-HT and 5-HIAA. Marked elevation of the 5-HT precursor TRP and of GABA was present in both the necrotic center and perifocal edema of acute infarcts, which also showed a mild reduction of total proteins. The degradation zone surrounding old infarcts showed a mild decrease of both 5-HT and 5-HIAA with normal TRP levels, indicating normalization of the previously increased 5-HT metabolism and turnover after decrease of acute cerebral edema. These data which confirm previous studies in experimental cerebral ischemia and stroke indicate that disorders in the metabolism of brain monoamines and other putative neurotransmitters contribute to the development of postischemic brain damage and the complicating cerebral edema. They are also in keeping with the concept that unilateral focal ischemia produces bilateral effects on brain monoamines.
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PMID:Changes of some putative neurotransmitters in human cerebral infarction. 3 76

We measured the action of dopamine given intravenously at dosage ranging from 2.5 to 320 micrograms/kg per min in closed chest anaesthetized dogs. Dopamine produced a dose-dependent increase in heart rate, cardiac index, mean arterial pressure, total peripheral resistance, pulmonary artery pressure, left ventricular end diastolic pressure, coronary flow and myocardial oxygen consumption. At dopamine dosage of 80-320 micrograms/kg per min, the coronary vascular resistance, the stroke volume index, the efficiency of heart work and the central venous pressure are all decreased. The maximum effect of dopamine on the circulation was seen at a dose between 40 and 80 micrograms/kg per min.
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PMID:Dopamine effects on circulation and myocardial oxygen supply. 26 1

The haemodynamic effects of dobutamine (2 microgram/kg . min and 4 microgram/kg . min) and dopamine (4 microgram/kg . min and 8 microgram/kg . min) were studied in 17 patients with coronary artery disease prior to coronary bypass surgery. The study was performed under general anaesthesia (modified neurolept analgesia) and controlled ventilation. Dopamine improved cardiac index significantly, increased mean aortic pressure slightly while heart rate and total peripheral resistance remained unchanged. Dobutamine failed to increase cardiac and stroke index significantly, but increased mean aortic pressure distinctly due to an elevated total peripheral resistance. Both catecholamines increased left ventricular filling and mean pulmonary artery pressure. The HR x ASP-product which is closely related to left ventricular oxygen consumption was found to be augmented to a greater extent during dobutamine. For the above reasons dopamine should be favoured for increasing cardiac output in patients undergoing aortocoronary bypass surgery. Our study does not confirm earlier results which have shown dobutamine to be the preferable catecholamine. The possible reasons for this discrepancy are discussed.
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PMID:[The haemodynamic effects of dobutamine and dopamine in patients with coronary artery disease. A study performed under general anaesthesia (author's transl)]. 31 60

The haemodynamic effects of Dopamine (100, 250 and 500 mcg/min), Epinephrine (4 and 8 mcg/min), Orciprenaline (4 and 8 mcg/min) and two combinations of Dopamine 250 mcg/min with Epinephrine and Orciprenaline 4 mcg/min respectively at constant infusion rates were studied in 21 patients after cardiac surgery. Special attention was payed to four types of catecholamine infusions during which the highest cardiac index (CI), 161-168% of control, was seen: Dopamine 500 mcg/min (D 500), Epinephrine 8 mcg/min (E 8), Dopamine 250 mcg/min combined with Epinephrine 4 mcg/min (D 250 + E4) and Dopamine 250 mcg/min combined with Orciprenaline 4 mcg/min (D 250 + Or 4). At the same time mean arterial pressure (MAP) was highest with D 500 (137%) and lowest during both combined infusions (120 and 125%). Total peripheral resistance (TPR) was lowest during the combined infusions (80 and 81% of control) and highest during D 500 (89%). The relative increase of stroke index (SVI) and heart rate (HR) in favor of SVI, given as a quotient SVI/HR, was highest with D 250 + E4(3.7), followed by E 8 (1.9), D 500 (1.6) and D 250 + Or 4 (1.3). It was concluded that a combined infusion of Dopamine and Epinephrine, both in low doses, is preferable to a high dose of Dopamine, or Epinephrine alone, producing the same increase of cardiac output with less afterload and less chronotropic effect than high doses of either drug alone.
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PMID:Haemodynamic effects of dopamine, epinephrine and orciprenaline (Alupent) in patients early after cardiac surgery. 34 Apr 87

Although dopamine is a useful therapeutic agent to augment cardiac function in adults, there is little information about the hemodynamic effects of dopamine in children. To delineate the hemodynamic effects of dopamine in children, we infused two doses of dopamine (2 and 7.75 micrograms/kg/min) into 10 children during diagnostic cardiac catheterization. We measured heart rate, systemic arterial, pulmonary arterial, right atrial, and pulmonary capillary blood pressure, and cardiac output. During infusion of 7.75 micrograms/kg/min of dopamine, cardiac index increased from 3.9 to 5.4 L/min/m2, stroke volume increased from 43 to 57 ml/stroke and systemic vascular resistance declined from 1,697 to 1,165 dynes-cm-5-sec-m2. These indices also were changed significantly from control during infusion of 2 micrograms/kg/min of dopamine. The ratio of mean pulmonary arterial blood pressure to mean systemic arterial blood pressure in one patient with pulmonary vascular obstructive disease increased from 0.73 to 1.15, and ventricular bigeminy occurred during infusion of 7.75 micrograms/kg/min of dopamine. Dopamine is a potentially useful inotropic agent in children, but the use of dopamine may be contraindicated in patients with elevated and fixed vascular resistance.
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PMID:The hemodynamic effect of dopamine in children. 49 32

Catecholamines increase not only oxygen delivery to tissues but also oxygen consumption (VO2). The effect of an infusion of dopamine hydrochloride has been studied at two doses, each in six dogs. Dopamine 10 micrograms kg-1 min-1 caused an increase in haemoglobin concentration and altered cardiac output, oxygen availability and total body oxygen consumption such that oxygen availability ratio increased and (CaO2-CVO2) decreased although these changes were not statistically significant. Dopamine 30 micrograms kg-1 min-1 increased (P less than 0.05) heart rate, haemoglobin concentration and CaO2 and significantly reduced stroke volume and VD/VT. Although oxygen availability increased, increases in oxygen consumption were greater and this resulted in a statistically insignificant reduction in oxygen availability ratio and an increase in (CaO2-CVO2). Terminating the dopamine infusion resulted in significant (P less than 0.05) decreases in cardiac output, PVO2, CaO2), oxygen availability and oxygen consumption and an increase in (CaO2-CVO2). It was concluded that maximum oxygen delivery occurs at a lower dose than that required to produce the maximum increase in oxygen consumption.
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PMID:Oxygen transport during dopamine infusion in dogs. 51 1

Experiments were performed on 19 anaesthetized open-chest dog instrumented with polyethylene catheters inserted: into the aorta, in pulmonary artery and in left atrium and with an electromagnetic flow-transducer placed around the ascending aorta in order to record : systemic arterial and pulmonary pressures, mean left auricular pressure and phasic aortic flow. Heart rate, stroke volume, total systemic and pulmonary resistance, cardiac work were moreover calculated. Each dog was given intravenously by slow infusione : Dopamine (micrograms 5--10--20/kg/min/ 5 min), Isoproterenol (microgram 0.125--0.25--0.5/kg/min/5 min) and Norepinephrine (microgram 0.25--0.5--1 /kg/min/5 min). Results obtained on systemic hemodynamics agree with those reported by many other investigators. On pulmonary circulation : Isoproterenol, at the tested doses, elicited vasodilator effects, Norepinephrine increased total pulmonary resistance but not pulmonary vascular resistance, while Dopamine did not modify or slightly reduced vascular pulmonary tone.
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PMID:[Effects of dopamine, noradrenaline and isoproterenol on pulmonary circulation in anesthetized dogs]. 55 Aug 77

Dopamine-beta-hydroxylase (DBH) activity was higher in the serum, the mesenteric artery and the cerebral cortex of 4-week-old stroke-prone spontaneously hypertensive rats (SHRSP), and lower in the nucleus tractus solitarii than it was in spontaneously hypertensive rats (SHR).
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PMID:Dopamine-beta-hydroxylase activity in stroke-prone spontaneously hypertensive rats. 63 Dec 49

Thirteen patients with severe cardiac failure underwent a single crossover study of dopamine and dobutamine in order to compare the systemic and regional hemodynamic effects of the two drugs. The dose-response data demonstrated that dobutamine (2.5--10 microgram/kg/min) progressively and predictably increases cardiac output by increasing stroke volume, while simultaneously decreasing systemic and pulmonary vascular resistance and pulmonary capillary wedge pressure. There was no change in heart rate or premature ventricular contractions (PVCs)/min at this dose range. Dopamine (2--8 microgram/kg/min) increased the stroke volume and cardiac output at 4 microgram/kg/min. Dopamine at less than 4 microgram/kg/min provided little additional increase in cardiac output and increased the pulmonary wedge pressure and the number of PVCs/min. At greater than 6 microgram/kg/min, dopamine increased heart rate. During the 24-hour maintenance-dose infusion of each drug (dopamine 3.7--4, dobutamine 7.3--7.7 microgram/kg/min), only dobutamine maintained a significant increase of stroke volume, cardiac output, urine flow, urine sodium concentration, creatinine clearance and peripheral blood flow. Renal and hepatic blood flow were not signfiicantly altered by the maintenance dose of either drug. Systemic and regional hemodynamic data suggest that dobutamine has many advantages over dopamine when infused in patients with cardiac failure.
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PMID:Comparative systemic and regional hemodynamic effects of dopamine and dobutamine in patients with cardiomyopathic heart failure. 67 37


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