Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 21-year old women taking oral contraceptives suffered thromboembolic stroke associated with mitral valve prolapse. She had been using an unspecified oral contraceptive for 3 months postpartum, and had smoked a pack a day for 5 years. She complained of sudden right orbital headache, left-sided weakness and pain. Clinical exam showed left sided anopsia, facial paralysis, tongue protrusion, parietal sensory deficit, and loss of position sense. Computed tomography suggested a lesion near the right middle cerebral artery; and cerebral angiography revealed an 8 x 2 mm filling defect in that artery. A midsystolic click without a murmur was evident in the cardiac exam. Thickened, redundant mitral valve leaflets with marked prolapse, and a mass on the atrial side of the posterior leaflet appeared on the echocardiogram. The atrial thrombus was considered the source of the apparent embolism in the cerebral artery. Oral contraceptives have been found to increase the risk of thrombotic stroke and venous thromboembolism. Therefore, women with known mitral valve prolapse or leaflets may be advised not to use the pill.
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PMID:Embolic stroke in a woman with mitral valve prolapse who used oral contraceptives. 374 65

Twelve patients in shock, defined as being present if the mean arterial blood pressure was less than 60 mm Hg, pulmonary arterial occlusion pressure was 15 mm Hg or greater, urine output was 20 ml or less for 2 consecutive hours, and there was clinical evidence of poor peripheral perfusion, underwent a comparative therapeutic trial with dopamine at 200 micrograms . min-1 and 400 micrograms . min-1 (2.5-5.5 micrograms . kg-1 . min-1), dobutamine 250 micrograms . min-1 and 500 micrograms . min-1 (3.5-7 micrograms . kg-1 . min-1) and isoproterenol 2 micrograms . min-1 and 4 micrograms . min-1 (0.025-0.055 micrograms . kg-1 . min-1). Isoproterenol at 2 micrograms . min-1, produced a significant increase in pulse rate, cardiac output, left ventricular stroke work index and decrease in mean pulmonary blood pressure and pulmonary arterial occlusion pressure and at 4 micrograms . min-1 a significant increase in stroke volume, mixed venous oxygen tension and decrease in right atrial pressure and systemic vascular resistance was also observed. Dopamine at 200 micrograms . min-1 produced a significant increase in cardiac output, pulmonary arterial occlusion pressure and mixed venous oxygen tension and at 400 micrograms . min-1 a significant increase in pulse rate, mean arterial blood pressure mean pulmonary blood pressure, right ventricular stroke work index, right atrial pressure and pulmonary arterial occlusion pressure and decrease in arterial oxygen tension was also observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A comparison of dopamine, dobutamine and isoproterenol in the treatment of shock. 396 95

Adequate heparinization is considered to prevent stroke in pregnant women with prosthetic heart valves. A 21-year-old pregnant woman with a Starr-Eduards prosthetic mitral valve and atrial fibrillation experienced repeated cerebral embolic events despite full heparinization.
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PMID:Failure of continuous intravenous heparinization to prevent stroke in a pregnant woman with a prosthetic valve and atrial fibrillation. A case report. 404 36

The cardiovascular effects of an intravenous infusion of adrenaline (10 mug./min.) and isoprenaline (0.75 mug./min.) have been compared in two groups of six patients in the early post-operative period following aortic valvar homograft replacement. These doses were chosen to produce obvious haemodynamic effects without precipitating dysrhythmias. Though both drugs have been shown to improve the circulatory state, adrenaline caused a greater change in stroke volume and in arterial pulse pressure, and for any given rise in heart rate a greater increase in the cardiac index. In addition, adrenaline caused a greater improvement in the relation between oxygen demand and oxygen supply of the body. Isoprenaline did not cause an increase in systolic and pulse pressure and always aggravated hypoxaemia. It is concluded from this study that adrenaline is the more satisfactory drug to use in the early post-operative phase following aortic valvar homograft replacement.
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PMID:Comparison of haemodynamic effects of intravenous isoprenaline and adrenaline after aortic valvar homograft replacement. 542 85

The hemodynamic effects of isoproterenol infusion, 0.5 mug/kg per min were evaluated in eight intact anesthetized dogs during cardiac tamponade. During tamponade, the mean of pericardial pressures was increased from - 1.5 to 12.5 mm Hg, and the mean of right atrial pressures was increased from 1 to 12.4 mm Hg. Mean cardiac output fell from 144.8 to 44.8 ml/kg per min (P < 0.001), and rose to 105.6 ml/kg per min (P < 0.001) with isoproterenol. Mean cardiac stroke volume fell from 20.3 to 6.1 ml during tamponade (P < 0.001) and rose to 12.1 ml with isoproterenol (P < 0.001). The heart rate increased from 193.3 beats/min during tamponade to 217.5 beats/min with isoproterenol (P < 0.05). During isoproterenol infusion, the mean right atrial pressure and mean pericardial pressure decreased significantly. With cardiac tamponade, the mean blood pressure fell from 157.5 to 126.1 mm Hg (P < 0.01) and did not change significantly with isoproterenol, 11 additional animals were studied with norepinephrine infusion during tamponade. There were no consistent hemodynamic effects with infusions of 0.5 and 1 mug/kg per min. With norepinephrine 2, 5, and 10 mug/kg per min cardiac output rose in some experiments. Isoproterenol infusion increased the cardiac output during tamponade principally by increasing cardiac stroke volume and to a lesser degree by increasing the heart rate. It is postulated that the increased stroke volume resulted from an increased ejection fraction with greater decrease in end-systolic than end-diastolic ventricular volume. These effects are consistent with the known positive inotropic, peripheral vasodilator, and positive chronotropic effects of isoproterenol.
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PMID:Hemodynamic effects of isoproterenol and norepinephrine in acute cardiac tamponade. 577 87

A prospective study of advanced cardiopulmonary resuscitation (CPR) was carried out on 226 patients in order to examine factors predicting successful resuscitation and 6 month survival. The mean age of all patients was 70 years and median age was 74. Cardiopulmonary resuscitation was successful in 40.5% (137) of all arrests and in 48.7% (110) of the first arrests. Thirty of 207 patients with one or more cardiac arrests were discharged alive (14%). Twenty-one of our patients were alive at 6 months (10.3%). Patients in ventricular fibrillation and/or ventricular tachycardia at the time of arrest were more likely to have successful outcomes. When the patient required Isuprel or bicarbonate, cardiopulmonary resuscitation was significantly less successful. We found no correlation of immediate outcome with the following variables: location of arrest; time of day; pre-existence of shock; coma; stroke; malignancy. Uremia and/or chronic obstructive pulmonary disease was not significantly associated with failed resuscitation. Most notable in our results of specific treatments was the evidence for the need to improve the initial pH, particularly when it was less than 7.2. Failure to do so by the time the second blood gas was drawn was associated with failure of cardiopulmonary resuscitation. Our results also suggest that the adequate treatment of metabolic acidosis, and improved ventilatory management with improved PO2 and optimization of PCO2, play a role in the better outcome of cardiopulmonary resuscitation.
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PMID:Cardiopulmonary resuscitation in a hospitalized population: prospective study of factors associated with outcome. 609 Dec 4

Hemodynamic properties of medroxalol (MDL), a new alpha-and-beta adrenoceptor antagonistic drug, were studied in eight pentobarbital-anesthetized (open chest) dogs. MDL was injected in three doses (1.5, 3.0 and 9.0 mg/kg i.v.) at one hour intervals. A control group (n = 5) received three successive vehicle injections at the same time intervals. Heart rate, systolic and diastolic arterial pressure, cardiac output and stroke volume (using an intrathoracic flowmeter), and peripheral resistance were recorded 45 min before the first injection and 15 min after each administration. Isoproterenol (ISP) and neosynephrine (NSP) dose-response curves were recorded before the first dose and after each injection in both group. Log-linear regression analyses were used to estimate the ISP chronotropic dose 25 (DC 25) and the ISP barotropic dose 30 (DB 30). The results show that medroxalol possesses beta-adrenoreceptor antagonistic properties which are 35 times greater than its alpha-antagonistic properties. Beta-blockade was evidenced by bradycardia and increase in DC 25, beginning at the first dose used. Alpha-blockade was not significant at that first dose and therefore cannot alone explain the strong hypotension observed. All these effects were related to the plasma-concentration of MDL.
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PMID:[Hemodynamic effects of medroxalol in the anesthetized dog. Relation between adrenolytic properties and plasma concentration]. 614 82

These studies were undertaken to clarify the role of the central and peripheral sympathetic nervous system and the renin-aldosterone system on the onset and maintenance of high blood pressure in essential hypertension (EH), and the following examinations were performed: 1) Urinary free norepinephrine and epinephrine excretion (UNEf and UEf), urinary conjugated norepinephrine and epinephrine excretion (UNEconj and UEconj), plasma norepinephrine and epinephrine concentration (PNE and PE), plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured in 52 patients with EH, who were divided into two groups (borderline EH: b-EH, and sustained EH: s-EH), and fifteen normals (N). 2) Cardiac index (CI), total peripheral resistance index (TPRI), appearance time, mean transit time and stroke index (SI) were determined by the dye-dilution method in eight patients with b-EH, ten patients with s-EH and ten N. 3) Clonidine was administered orally in a single dose of 150 micrograms to seven patients with s-EH and three patients with b-EH, and PNE, PE and growth hormone (GH) were measured before and after the administration. 4) Isoproterenol was infused intravenously in a dose of 0.02 microgram/kg/min for 30 min to 18 patients with s-EH and six N, then plasma cyclic AMP (c-AMP) and PRA were determined before, during and after the infusion. 5) Methacholine was injected intramuscularly in a dose of 10 mg to seven N, and PNE, PE and PRA were measured before and after the injection. There were no significant differences of PNE, PE, UNEf and UEf among the three groups (b-EH, s-EH and N), but UNEconj in both b-EH and s-EH was higher than in N (b-EH: p less than 0.1, s-EH: p less than 0.05). PRA in s-EH was slightly lower not only in N but also in b-EH. PAC in b-EH and s-EH was slightly lower than in N. The difference of PAC between b-EH and s-EH was not found. CI and SI were higher than in N (p less than 0.05), but TPRI was normal. In s-EH, TPRI was slightly elevated as compared with b-EH (p less than 0.1). In s-EH, clonidine caused a significant lowering of both blood pressure and PNE with a simultaneously marked increment of GH; on the other hand, in b-EH blood pressure and PNE did not change significantly in spite of the distinct rise of GH. After the isoproterenol infusion, PRA and c-AMP increased, and there was a significant correlation between the initial level of PRA and the maximal increment of PRA after the infusion in both s-EH and N.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Studies on the role of the central and peripheral sympathetic nervous system and the renin-aldosterone system on the onset and maintenance of high blood pressure in essential hypertension]. 632 58

The acute metabolic and hemodynamic effects of dopamine, dobutamine (both at 10 micrograms . kg-1 . min), and isoproterenol (at 0.05 or 0.1 micrograms . kg-1. min) were determined in dogs following 20 minutes of normothermic global myocardial ischemia. The catecholamines were started 10 minutes before cardiopulmonary bypass (CPB) was discontinued and were continued for 1 hour after bypass. Regional myocardial and systemic blood flow distribution was measured by means of the radioactive microsphere technique. On bypass all catecholamines sharply increased heart rate, myocardial oxygen consumption, and left ventricular blood flow (p less than 0.01). Because the hearts were unloaded, these data suggest that velocity of contraction is an important component of myocardial oxygen consumption. Although these drugs did not lower myocardial adenosine triphosphate (ATP) and creatine phosphate (CP) levels, the significant rise in oxygen consumption suggested that inotropic treatment on bypass may not be beneficial. Furthermore, renal blood flow was diminished in dobutamine-treated dogs (p less than 0.01) and tended to decrease with isoproterenol infusion. No change was seen with dopamine infusion. After bypass, dobutamine treatment increased cardiac output (p less than 0.01) and stroke volume (p = 0.017) with no change in heart rate, myocardial oxygen consumption, high-energy phosphate levels, and total or transmural distribution of left ventricular blood flow. Dopamine infusion did not change cardiac output but did increase oxygen consumption (p less than 0.01). Isoproterenol showed a slight inotropic effect, but frequent ventricular arrhythmias were present during weaning from bypass. In all treatment groups, blood flow in the other systemic beds (cerebral, gastrointestinal, and renal) was similar to that in control dogs. These data suggest that dobutamine is the most efficient of the drugs tested for support of the heart following global myocardial ischemia but, when given during bypass, it appears to decrease renal blood flow.
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PMID:Comparison of catecholamine effects on canine myocardial metabolism and regional blood flow during and after cardiopulmonary bypass. 670 Feb 52

We describe herein an isolated working heart preparation of guinea pigs, in which coronary perfusion pressure can be varied independently from afterload by directing left ventricular stroke volume into an artificial circulation. This preparation proved to be functionally stable, exhibited hemodynamic features characteristic of the heart in situ, and shows the phenomena of flow autoregulation, reactive hyperemia, and hypoxic and metabolic vasodilation. Myocardial oxygen consumption and coronary flow were tightly coupled when cardiac work was enhanced by either 1.5-6.0 X 10(-9) M isoproterenol (r = 0.975) or changes of afterload (20-100 mm Hg) (r = 0.890). Isoproterenol-induced changes in adenosine release correlated with changes of coronary flow (r = 0.869) and myocardial oxygen consumption (r = 0.894). The concentrations of endogenously formed adenosine were within the vasodilatory range of exogenously applied adenosine. In contrast, afterload-induced changes in myocardial oxygen consumption were not associated with an enhanced release of adenosine, inosine, and hypoxanthine, and did not correlate with coronary resistance (r = 0.422). The specific activity in the effluent perfusate of intracoronarily infused [8-14C]adenosine was increased with elevated afterload, suggesting that less adenosine was liberated by the heart. Our findings indicate that adenosine formed in response to beta-adrenergic stimulation is a major metabolite adjusting coronary flow to myocardial needs. Adenosine, however, does not appear to be involved in the afterload-induced changes in coronary flow when coronary perfusion pressure and, thus, oxygen supply are increased simultaneously. It is likely that formation of adenosine is not triggered by changes in MVO2 as such, but may critically depend on the oxygen supply: demand ratio.
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PMID:Relationship between myocardial oxygen consumption, coronary flow, and adenosine release in an improved isolated working heart preparation of guinea pigs. 682 19


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