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

Even during adequate general anesthesia, hypertension is a common phenomenon in patients undergoing aortocoronary bypass grafting (CABG). In such cases application of vasodilators is recommended in order to decrease myocardial oxygen consumption. This study was performed to compare two commonly used substances, i.e., nitrates and nifedipine, with regard to their influence on hemodynamics, renal blood flow, kidney function, and the requirement for homologous blood transfusions. METHODS. Forty-four patients gave their informed consent to the study. They were randomly divided into 2 groups: group 1 received nitroglycerin (3.0 micrograms/kg.min), group 2 nifedipine (Adalat, 0.5 microgram/kg.min) in order to prevent hypertension in the phase before onset of cardiopulmonary bypass (CPB). Anesthesia was induced by etomidate and succinylcholine and maintained as a modified neuroleptanalgesia with fentanyl (up to 50 micrograms/kg), midazolam (0.3 mg/kg.h), and pancuronium (0.1 mg/kg). Systolic blood pressure was kept within the range of 120-160 mm Hg; in case of higher values boluses of either 0.25 mg nitroglycerin or 0.5 mg nifedipine were administered. Cardiac index, stroke volume index, rate-pressure product, intrapulmonary shunt, and pulmonary and total peripheral resistances were evaluated at five predefined points: (1) after induction of anesthesia; (2) before incision; (3) before cannulating the aorta; (4) after decannulating the aorta; and (5) at the end of operation. Creatinine and free-water clearances as well as sodium and potassium excretion were calculated for three phases of the operation: (A) induction of anesthesia--onset of CPB; (B) during CPB; and (C) end of CPB--end of operation. CPB was performed using a membrane oxygenator (Sorin 51) and a nonpulsatile blood flow of 2.5 1/min.m2, which was reduced during mild hypothermia of 30-32 degrees C to 1.7 l/min.m2. Mean arterial pressure in both groups was kept at approximately 70 mm Hg. In case of lower pressures norepinephrine (50-100 micrograms/bolus) was administered; higher pressures were treated as described above. Volume substitution was performed initially by 500 ml hydroxyethyl starch and continued, if necessary, by homologous blood or 5% human albumin in order to keep the hematocrit greater than 30 in the phases before and after CPB. RESULTS. Group 2 showed significantly higher values of cardiac index and stroke volume index at point 3 while the rate-pressure product was clearly lower, indicating better myocardial performance and lower oxygen consumption than in group 1. Creatinine and free-water clearances in all three phases did not differ. However, sodium excretion during CPB was significantly higher in the nifedipine group while potassium excretion showed no differences. The average requirement for blood and blood substitutes was lower in group 2, but the difference could not be confirmed statistically because of the large dispersion of values. Nevertheless, 4 patients in the nifedipine group but no patient in group 1 did not need homologous blood transfusion. CONCLUSION. In comparison to nitrates, nifedipine showed some advantages in the treatment of hypertension during CABG: (1) it provided better myocardial performance; (2) it had a more reliable but not too long-lasting effect on elevated total peripherial resistance, leading to better hemodynamic stability; and (3) by not affecting the capacitance vessels it may necessitate fewer homologous blood transfusions.
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PMID:[Nifedipine versus nitroglycerin in aortocoronary bypass surgery. The effect on hemodynamics, kidney function and homologous blood requirement]. 153 39

Nifangin (nifedipine), manufactured by the Laakepharmos Co., Finland, was used in 75 patients with congestive heart failure due to ischemic heart disease and chronic obstructive bronchitis. The effect of a single 20 mg dose and a course of treatment (60 mg daily for 18 days) was assessed by monitoring with the help of echocardiography, venous occlusion plethysmography, laser Doppler flowmetry as well as external respiration and blood gases partial tension measurement. In patients with chronic obstructive bronchitis, the drug was used in combination with cardiac glycosides and diuretics. A single dose of nifangin reduced regional vascular resistance by 33%, and increased volumetric blood flow rate by 51%. The treatment course increased the stroke index and the cardiac index (by 21 and 23%, respectively) and improved blood oxygenation and external respiration parameters. The absence of side effects makes nifangin one of the most effective vasodilating agents, indicated for patients with congestive heart failure.
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PMID:[Effect of the calcium antagonist nifangin on hemodynamics in patients with congestive heart failure]. 267 59

18 patients with II NYHA class chronic congestive heart failure (CCHF) had been given nifedipine (Cordipin) 54.4 +/- 12.0 mg (day) for 6 weeks (group I). In 25 patients with III--IV NYHA class CCHF after 2-week optimal improvement of a clinical state with digoxine (D) and furosemide (F), nifedipine (N) had been added for 2 weeks/mean daily dose -- 40.8 +/- 12.8 mg (group II). Estimation of a left ventricular function using 2-DE and a submaximal effort tolerance as well as clinical examinations were carried out initially, after 2 and 6 weeks in group I, whereas in group II post D, F 2-week therapy and after next 2 weeks of combined D, F, N treatment. Nifedipine significantly increased ejection fraction from 44.2 +/- 13.0% to 49.0 +/- +/- 12.6% and decreased myocardial oxygen demand factor from 23.36 +/- 9.81 to 21.08 +/- 7.55 X 10(3) (p less than 0.05). Nonsignificant but marked increase of diuresis, cardiac and stroke indices as well as body weight loss were observed. Nifedipine addition to D and F neither improved nor deteriorated examined parameters in patients with III-IV NYHA class CCHF. Nifedipine did not also improve the submaximal exercise tolerance in both groups.
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PMID:[Evaluation of the effect of nifedipine in patients with chronic congestive heart failure]. 269 39

Nifedipine (Adalat) was used in managing acute hypertension in 20 patients with coronary heart disease during endarterectomy for carotid stenosis. Nifedipine (Adalat) was given if the cardiac index dropped below 2.5 l/min and the total peripheral resistance increased above 2,500 dyn/sec cm-5. In these patients the systolic blood pressure was 20% higher than the control value. After IV bolus injection of 1 mg nifedipine we noticed a 64% increase of the stroke volume index and a statistically significant 56% decrease of the total peripheral resistance. These values became stable under a maintenance dose. The left ventricular stroke work index increased after IV bolus injection and subsequently, by about 7%. This increase was statistically not significant. To evaluate the myocardial contractility, the heart rate and systolic pulmonary capillary wedge pressure were measured. After greatly raised values in hypertensive emergency, these parameters showed a 27% decrease following IV bolus injection and during the subsequent intraoperative course they stabilised at standard levels. The heart rate increased by about 10%, but this was statistically not significant. In accordance with the increase in heart rate, the coronary perfusion pressure decreased by about 31% (expressed in mm Hg) (mean value) and dropped even lower in some patients. The parameters for preload, central venous pressure and pulmonary capillary wedge pressure did not show any statistically significant changes. The authors conclude that nifedipine (Adalat) can be used with good results in treating hypertensive emergencies associated with low-output syndrome in patients with coronary heart disease during carotid endarterectomy.
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PMID:[Treatment of hypertensive crises with nifedipine (Adalat) in patients at risk of infarct during interventions on the extracranial cerebral vessels]. 360 47

A study was made of a vasodilating effect of nifedipine on the hemodynamics of 30 patients with chronic postinfarction left ventricular aneurysm, with chronic cardiovascular insufficiency of the II-III degree according to NYHA. A mean value of the acontractile segment on ventriculograms was 32.5 +/- 1.7%. The main parameters of systemic hemodynamics were studied by a method of integral body rheography 1 hour before and after sublingual intake of 20 mg of nifedipine (Corinfar, GDR) at rest, after exercise and during rehabilitation. An increase in the stroke and cardiac indices at rest by an average of 16% was revealed including a noticeable nifedipine effect in patients with elevated final diastolic pressure or arterial tension. During physical exercise a tendency toward an increase in the cardiac output was observed, mainly at the expense of a rise of the stroke volume after drug intake.
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PMID:[Effect of nifedipine in chronic left ventricular insufficiency in patients with post-infarction heart aneurysm]. 373

Issues raised recently concerning the safety of calcium channel blockers (CCBs) prompted an analysis of the occurrence of cardiovascular events and death in the Pfizer Inc. hypertension clinical trial databases for amlodipine (Norvasc) and nifedipine in the gastrointestinal therapeutic system (GITS) formulation (Procardia XL). Prospectively defined analyses of data from comparative and noncomparative trials of amlodipine and nifedipine GITS were conducted. Outcome measures included cardiovascular and noncardiovascular deaths, and adverse cardiovascular events including new/worsened angina, myocardial infarction (MI), serious arrhythmia, stroke, congestive heart failure, and bleeding. Among all amlodipine-treated patients (n = 32,920), the incidence rates for all-cause death, MI, and new/worsened angina were 3.0, 3.3, and 1.6/1,000 patient-years of exposure, respectively. Among those in comparative trials alone (n = 4,126), the all-cause death rate was 4.1/1,000 patient-years, which was comparable to that of other non-CCB agents and significantly less than that of other CCBs (23.8/1,000 patient-years, p = 0.015), although the difference in rates represents only 2 deaths. Among all nifedipine-GITS-treated patients (n = 2,645), the rate of all-cause death was 4.1/1,000 patient-years, of MI 6.5/1,000 patient-years, and of new/ worsened angina 5.7/1,000 patient-years. The incidence rates for MI and other cardiac events were low in these hypertension trials, and did not differ among treatment groups in either the amlodipine or nifedipine GITS comparative analyses. In the clinical trial databases analyzed, there is no signal suggesting excessive risk of death or cardiovascular events for hypertensive patients treated with amlodipine or nifedipine GITS.
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PMID:Safety of long-acting dihydropyridine calcium channel blockers in hypertensive patients. 959 99

The release of Adalat Oros 60 on the Belgian market was justified since it has been clearly demonstrated that the dosage of 60 mg significantly increases the proportion of responders to nifedipine monotherapy. This gives us the opportunity to briefly review the history of nifedipine and to describe the original and ingenious galenic controlled-release formulation known as Oros (Gastrointestinal Therapeutic System, or GITS in the anglo-saxon world). Cleary, nifedipine is a potent calcium antagonist the action of which is now smooth and devoid of the usual ups and downs observed with the regular capsules, even in their Retard form. These abrupt changes in plasma concentrations, with the subsequent variations in heart rate and blood pressure, were dangerous and bothersome. Oros allows plasma concentrations of nifedipine to plateau for at least 24 hours after oral administration. This reduces the incidence of side-effects which remain those classically attributable to calcium antagonists (i.e.: flushes, headaches); interestingly, they tend to appear early after treatment initiation which allows to easily ascribe them to the drug and to quickly assess tolerance. The INSIGHT trial compared the effects on nifedipine Oros to those of a classical diuretic combination (hydrochlorothiazide-amiloride) in 6321 hypertensives who had at least one additional risk factor for cardiovascular disease. The rate of the primary outcome (a composite of cardiovascular death, myocardial infarction, heart failure, stroke) was similar in the two treatment groups, but nifedipine was superior among the subgroup of diabetics. Substudies suggested that nifedipine slows the progression of atherosclerotic lesions (carotid and coronary arteries), preserves renal function, and prevents the development of new diabetes.
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PMID:[Medication of the month. Adalat Oros 60 mg]. 1513 4

The feeding behavior and venom toxicity of the coral snake Micrurus nigrocinctus (Serpentes: Elapidae) on its natural prey in captivity were investigated. Coral snakes searched for their prey (the colubrid snake Geophis godmani) in the cages. Once their preys were located, coral snakes stroke them with a rapid forward movement, biting predominantly in the anterior region of the body. In order to assess the role of venom in prey restraint and ingestion, a group of coral snakes was 'milked' in order to drastically reduce the venom content in their glands. Significant differences were observed between snakes with venom, i.e., 'nonmilked' snakes, and 'milked' snakes regarding their behavior after the bite. The former remained hold to the prey until paralysis was achieved, whereas the latter, in the absence of paralysis, moved their head towards the head of the prey and bit the skull to achieve prey immobilization by mechanical means. There were no significant differences in the time of ingestion between these two groups of coral snakes. Susceptibility to the lethal effect of coral snake venom greatly differed in four colubrid species; G. godmani showed the highest susceptibility, followed by Geophis brachycephalus, whereas Ninia psephota and Ninia maculata were highly resistant to this venom. In addition, the blood serum of N. maculata, but not that of G. brachycephalus, prolonged the time of death of mice injected with 2 LD(50)s of M. nigrocinctus venom, when venom and blood serum were incubated before testing. Subcutaneous injection of coral snake venom in G. godmani induced neurotoxicity and myotoxicity, without causing hemorrhage and without affecting heart and lungs. It is concluded that (a) M. nigrocinctus venom plays a role in prey immobilization, (b) venom induces neurotoxic and myotoxic effects in colubrid snakes which comprise part of their natural prey, and (c) some colubrid snakes of the genus Ninia present a conspicuous resistance to the toxic action of M. nigrocinctus venom.
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PMID:Feeding behavior and venom toxicity of coral snake Micrurus nigrocinctus (Serpentes: Elapidae) on its natural prey in captivity. 1553 56