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

Cardiac performance was assessed in 33 lambs less than 1 to 5 days of age by means of left ventricular function curves. Performance was quantified by determining stroke volume ejected at end diastolic pressure 10 cm H2O (SV10) with constant afterload. Coronary flow, myocardial O2 consumption (MVO2), blood gas tensions and pH were determined. Measurements were obtained before and at 30 min intervals following hemorrhage to 30 mm Hg arterial pressure, and in controls (arterial pressure 75 mm Hg). Effects of metabolic acidosis, hypercapnia and beta-blockade were determined. In control lambs acidosis and hypercapnia failed to reduce SV10 after two hours. In hemorrhaged animals both factors sharply reduced SV10 and lambs with prior beta-blockade showed no greater reduction. MVO2 fell following hemorrhage but did not differ with metabolic conditions and did not relate to SV10. It is concluded that beta-adrenergic function is critically important in preserving left ventricular performance in newborn exposed to acidosis or hypercapnia. With sustained hemorrhage this mechanism fails leading to a significant depression of ventricular function. MVO2 was not a determining factor in these studies.
Ann Surg 1976 Dec
PMID:Cardiac function and metabolism following hemorrhage in the newborn lamb. 1 55

Alterations in coronary blood flow associated with adaptation to high altitude were examined. Three normal men native to low altitude were studied, first at sea level, and again after 10 days' sojourn at 3,100 m altitude. During rest at high altitude, a 32% decrease in coronary blood flow was largely offset by a 28% increase in coronary arterial O2 extraction to maintain myocardial O2 delivery. The increase in O2 extraction resulted mainly from a decrease in coronary sinus blood O2 content and saturation. However, coronary sinus O2 tension remained constant, implying a decrease in the affinity of hemoglobin for O2. These observations are consistent with the hypothesis that coronary blood flow is regulated to maintain constant myocardial tissue O2 tension (as reflected here by coronary sinus blood O2 tension). The absence of a decrease in coronary sinus O2 tension or a decrease in myocardial lactate extraction imply that myocardial hypoxia did not develop. Therefore, myocardial hypoxia is not the basis for the decrease in cardiac stroke volume at high altitude reported previously and also observed in the present study.
J Appl Physiol 1976 Dec
PMID:Alterations in the coronary circulation of man following ascent to 3,100 m altitude. 1 30

Awake domestic pigeons, either maintained at 22 degrees C (series I) or acutely exposed at 2 degrees C (series II), were studied in a hypobaric chamber at 140 m and at various stages during a 4-week exposure to 4000 m. Steady-state pulmonary ventilation (Vg) and breathing pattern (VT, fr), oxygen consumption (MO2), O2 concentrations and pressures in the arterial (a) and mixed venous blood (v), hematocrit (Ht) and acid-base status in arterial blood, systolic blood pressure and heart frequency (fH) were measured. From these data cardiac output (Vb) and stroke volume (Vs), ventilatory and circulatory requirements (Vg/MO2, Vb/MO2), extraction of O2 from inspired air (EgO2) and blood EbO2), and capacitance coefficient of blood for oxygen (betabo2) were calculated. At 140 m, by comparison with predicted values for mammals of same body weight, pigeons at 22 degrees C extracted more O2 from the inspired gas, with lower fR, larger VT, similar Vg; they extracted O2 from the blood like mammals, with lower fH, larger VS, greater Vb, similar betabO2=70 mumol-L-1-torr-1. Acute exposure to 2 degrees C provoked a two-fold increase in MO2 which was achieved by doubling Vg and increasing O2 extraction from the blood. At 4000 m, in both series, pigeons hyperventilated within the first 30 min, with a resultant hypocapnic alkalosis comparable to that in mammals. Further hyperventilation with consequent greater hypocapnia and increase of arterial PO2 was complete beyond 3 hr. After a few weeks, the pH remained 0.07 above control normoxic value, Ht increased from 45 to 52%, betabO2 reached about 172 mumol-L-1-torr-1. At 2 degrees C, Vb also increased, mainly due to tachycardia.
Respir Physiol 1976 Dec
PMID:Ventilatory and circulatory O2 convection at 4000 m in pigeon at neutral or cold temperature. 1 65

The studies were undertaken to determine whether isoflurance inhalation is associated with a degree of beta-adrenergic action that is potentially important in clinical situations, and to compare the circulatory tolerance to isoflurane and halothane in dogs following beta blockade. We measured arterial and pulmonary artery pressure, left and right ventricular filling pressure, heart rate and cardiac output, and derived stroke volume and systemic and pulmonary vascular resistances in 13 mongrel dogs. The haemodynamic response to 1 MAC and 2 MAC isoflurane was studied in seven dogs and was similar before and after propranolol 0.1mg/kg i.v. In six dogs, propranolol 0.5mg/kg caused no significant changes in the circulatory response to 1 MAC and 2 MAC isoflurane or 1 MAC halothane. However, in three dogs, administration of 2 MAC halothane after propranolol 0.5mg/kg resulted in such profound circulatory depression as to preclude further study. These data suggest that (a) isoflurane possesses no clinically important beta-adrenergic stimulating activity; (b) there is no adverse drug interaction upon the circulation with the combination of isoflurane and propranolol; (c) in the presence of moderated profound beta-adrenergic blockade, 2 MAC isoflurane may be tolerated better than 2 MAC halothane.
Br J Anaesth 1976 Dec
PMID:Lack of beta-adrenergic activity of isoflurane in the dog: a comparison of circulatory effects of halothane and isoflurane after propranolol administration. 1 56

1. Oxygen consumption and central haemodynamics were recorded at rest and during exercise in fifty-one men with essential hypertension (W.H.O. stage I) and repeated after 1 year on a single drug: alprenolol (n equals 10), atenolol (13) metoprolol (12) and timolol (16). 2. Mean arterial pressure was significantly reduced in all groups at rest (11-18%) and during exercise (5-11%). Heart rate was significantly reduced in all groups (20-28%) at rest and (17-26%) during exercise. Owing to increase in supine resting and exercise stroke volume in the alprenolol and atenolol group, cardiac index decreased less than heart rate---in contrast to the timolol group where cardiac index was decreased 26-32%. The calculated post-treatment total peripheral resistance was significantly increased at rest and during exercise in the timolol group. In the other groups the total peripheral resistance was significantly increased at rest when sitting, but not at rest when supine and during exercise. 3. It is concluded that the major haemodynamic changes induced in subjects with moderate and mild essential hypertension by these different beta-receptor blockers are the same, but that minor differences exist with respect to effect upon stroke volume and total peripheral resistance.
Clin Sci Mol Med Suppl 1976 Dec
PMID:Haemodynamic long-term effects of beta-receptor-blocking agents in hypertension: a comparison between alprenolol, atenolol, metoprolol and timolol. 1 59

Nineteen patients with ischemic heart disease were randomized into two groups and received either metoprolol or H 87/07. Heart catheterization was performed, and the groups were studied at rest and during exercise--before and after intravenous drug administration. During work metoprolol gave a statistically significant reduction in left ventricular work (expressed as pressure-rate product) of about 20%, mainly depending on a reduction in heart rate. Cardiac output decreased by 21%. Stroke volume was almost unchanged. The abnormal increase in left ventricular filling pressure during work was slightly, but not significantly, reduced by the drug. For H 87/07 no significant changes were found in the corresponding variables. This seems, however, to depend on an inadequate dosage, since not even the heart rate during work was significantly reduced. In conclusion, in the doses used metoprolol has been shown to be a potent beta-adrenoceptive antagonist in contrast to H 87/07.
Scand J Clin Lab Invest 1976 Dec
PMID:Hemodynamic effects of two cardioselective beta-adrenoceptive antagonists, metoprolol and H 87/07, in coronary insufficiency. 2 23

The effect of chronic beta blockade on the haemodynamic response to graded exercise was studied in 18 hypertensive patients treated with bunitrolol, which has partial agonist activity. The patients first received a placebo for 5 to 12 days, then bunitrolol 30 mg daily for one week and subsequently the dose was doubled weekly as necessary up to 240 mg daily. At rest haemodynamic changes after beta blockade were only minor; heart rate decreased by 8% and no significant change was observed in stroke index, cardiac index, (a-v)O2 difference and VO2. The hypotensive effect was not significant and no significant change in mean pulmonary arterial and wedge pressure was observed. Maximal exercise capacity remained unchanged, because of haemodynamic responses. The maximal exercise heart rate was reduced by 25% during beta blockade, which was compensated by a 34% elevation in stroke index, whereas maximal cardiac index and (a-v)O2 difference remained unchanged. There was no consistent change in mean pulmonary artery pressure during maximal exercise, but the mean brachial artery pressure fell by 12%.
Eur J Clin Pharmacol 1977 Dec 16
PMID:Haemodynamic response to graded exercise during chronic beta-adrenergic blockade with bunitrolol, an agent with intrinsic sympathomimetic activity. 2 95

Five male subjects performed exercise at 33, 66, and 95% of their maximum power output on three occasions in random order. Each study was preceded by a 3-h period in which capsules were taken by mouth, containing either CaCO3 (control, NH4Cl (acidosis), or NaHCO3 (alkalosis) in a dose of 0.3 g/kg body wt; preexercise blood pH was 7.38 +/- 0.015, 7.21 +/- 0.033, and 7.43 +/- 0.029, respectively. Exercise was continuous and maintained for 20 min at the two lower power outputs and for as long as possible at the highest. Compared with control (270 +/- 13 s), endurance time at the highest power output was reduced in acidosis (160 +/- 22 s) and increased in alkalosis (438 +/- 120 s). No differences were observed for central cardiovascular changes in exercise (cardiac output, frequency, or stroke volume). The respiratory changes expected from changes in blood pH were observed, with a higher alveolar ventilation in acidosis. At all power outputs arterialized venous lactate was lowest in acidosis and highest in alkalosis. Plasma glycerol and free fatty acids were lowest in acidosis. Changes in blood [HCO3-] and pH were shown to have major effects on metabolism in exercise which presumably were responsible for impaired endurance.
J Appl Physiol Respir Environ Exerc Physiol 1977 Dec
PMID:Effect of pH on cardiorespiratory and metabolic responses to exercise. 2 31

1. A study was conducted amongst 1247 treated hypertensive patients to determine the predictive power of untreated baseline and achieved treated blood pressures in the development of the complications of hypertension. In addition the relative importance of systolic and diastolic pressures was calculated. 2. Statistical analysis was done by calculating univariate differences in blood pressure between cases with and without complications. The higher the univariate distance, the greater the predictive power. 3. Blood pressures achieved during treatment were more important than baseline pressures for predicting stroke in both men and women, confirming the benefits of antihypertensive therapy in preventing strokes. 4. There was some evidence of prevention of myocardial infarction in men and of angina in women as a result of therapy. 5. There was no evidence to suggest that any one group of drugs, including beta-adrenoreceptor-blocking drugs and thiazides, conferred any extra benefit in preventing coronary heart disease. 6. The systolic blood pressures achieved during treatment predicted stroke better than diastolic pressure, but no consistent trends were found for coronary heart disease.
Clin Sci Mol Med Suppl 1978 Dec
PMID:Relation between prognosis and the blood pressure before and during treatment of hypertensive patients. 3 9

The heart of the old hemiplegic patient is examined as follows: 1. The preapoplectic situation of the heart which often induces in a conclusive manner the beginning of a stroke, 2. the occurrence of heart troubles with the stroke itself and 3. the influence of rehabilitation measures and the heart function. Preexistent heart troubles are very frequent (in ca. 80%). Thereby the hypertension with a left ventricular hypertrophy and later with heart failure play an important role. The stroke itself especially in subarachnoidal bleedings can cause severe electrocardiographic anomalies. The telemetric controlled heart shows specially while rehabilitation more extrasystoles and alterations of repolarisation but usually do not impair the rehabilitation. With a systematic rehabilitation (training) the heart is most favourably influenced.
Aktuelle Gerontol 1978 Dec
PMID:[The heart of the old hemiplegic patient (author's transl)]. 3 57


1 2 3 4 5 6 7 8 9 10 Next >>