Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intraoperative hypertension is a common problem in patients undergoing myocardial revascularization. Twenty patients who developed acute hypertension after sternotomy were studied. Ten patients received three doses of intravenous nitroglycerin (32, 64, and 96 mcg. per minute), and 10 patients received nitroprusside, (20, 40, and 60 mcg. per minute). All patients were anesthetized with morphine, diazepam, nitrous oxide, oxygen, and pancuronium bromide. Five patients in each group also received enflurane. The study compared the effects of nitroglycerin and nitroprusside on systemic hemodynamics, myocardial oxygen supply/demand relationships, and ischemic changes on the electrocardiogram. Both drugs decreased preload and afterload in a dose-related manner. Heart rate increased significantly only with the largest dose of each drug. Myocardial oxygen demand was decreased significantly by both drugs, while the coronary perfusion pressure was decreased more by nitroprusside. Both nitroglycerin and nitroprusside improved left ventricular performance. Nitroglycerin improved ST-segment depression in eight of 10 patients; while nitroprusside improved the ST segments in six patients, and worsened the ST segments in three patients. None of the nitroglycerin group had worsening of the electrocardiographic ST segments. These findings demonstrate that both drugs can control intraoperative hypertension and can decrease myocardial oxygen demand. Nitroglycerin was shown to improve ischemic changes on the electrocardiogram more often than nitroprusside.
 ...
PMID:Vasodilator therapy during coronary artery surgery. Comparison of nitroglycerin and nitroprusside. 10 11

The significance of asymptomatic episodes of ischemic type S-T segment depression was studied in 20 patients with coronary heart disease. Continuous 10 hour electrocardiographic recordings accompanied by detailed daily diaries of activity and symptoms were obtained periodically during a mean time of 16 months. All patients had ischemic type S-T depression associated with angina pectoris during treadmill exercise. Measurements of heart rate, S-T depression and exercise level at the onset of angina obtained during repeated controlled exercise tests at the start of each study period were compared with the measurements recorded during daily activity. After 2,826 hours of recording, 411 transient epidsodes of ischemic type S-T depression were noted during usual daily activity. Only 101 (25 percent) of these episodes were associated with angina. The remaining episodes were unrelated to other symptoms or to posture. All occurred at heart rates significantly lower than those observed at the onset of angina during exercise testing. Of these episodes of asymptomatic S-T depression, 72 percent occurred only at rest or during very light activity such as slow walking or sitting. Nitroglycerin administered hourly significantly reduced the frequency of these episodes, thus supporting the concept that they represent painless ischemia. Because the episodes of asymptomatic ischemic type S-T depression occurred more frequently than angina during usual daily activity and were evident at heart rates and activity levels well below those expected to evoke ischemia, they may be caused by factors other than those that cause angina.
 ...
PMID:Transient asymptomatic S-T segment depression during daily activity. 40 3

The antianginal effect of perhexiline was evaluated in a placebo-controlled double-blind study of 20 patients with stable angina pectoris. Only patients with documented myocardial infarction of more than 6 months' standing and with ST-segment depression on exercise were admitted to the study. Objective parameters of bicycle stress tests at a submaximum level of 50 watts and a maximum exercise level were evaluated. Subjective data such as nitroglycerin consumption and incidence of anginal attacks per week were obtained from the patients' self-maintained records. No negative chronotropic effect of perhexiline was found at rest. At a submaximum exercise level with unchanged double-product, a significantly lower heart rate (p less than 0.05) and a significant reduction in ST-segment depression were observed in comparison with the placebo. At maximum exercise level an increase in exercise tolerance of 8.1% and in aerobic capacity of 8.3% resulted in a significant increase in the double-product (p less than 0.01), with a shift in the blood pressure/heart rate ratio. Discontinuation of exercise occurred at the same heart rate, but at a markedly higher level of exercise attainment. Heart rate on exercise proved to be the most valuable parameter in this study for the evaluation of the aerobic capacity of the individual patient. Nitroglycerin consumption and frequency of anginal attacks per week were reduced, but were not of statistical significance. Side-effects occurred in 6 patients, but these did not require termination or reduction of medication. The selective effect on heart rate during exercise opens a new field of application for perhexiline in comparison with beta-blocking agents.
 ...
PMID:[Clinical efficacy of perhexiline maleate in stable angina pectoris (author's transl)]. 69 49

Regional myocardial function following occlusions of the circumflex coronary artery was studied in unanesthetized dogs using minature ultrasonic crystal pairs implanted subendocardially within the left ventricle for measurement of control, marginal, and ischemic lengths. As early as five beats after coronary occlusion, reduced function was apparent in ischemic zones, and an increase in heart rate occurred (78 to 115 beats/min) at an average of 25 sec. In the control zones, shortening initially increased from a constant end-diastolic length, but later end-diastolic length also increased by 7.5%. Shortening in the marginal zones was reduced by 50% at 90 sec as holosystolic expansion developed in the ischemic zones. On reperfusion, systolic function returned to normal within a few minutes while protodiastolic abnormalities persisted for up to 45 min. With coronary occlusions longer than two minutes most dogs exhibited arousal and further tachycardia; this reaction was prevented by morphine. During two minute occlusions morphine also decreased the heart rate increase by 37%, and marginal segment shortening was improved by 40%. Prior administration of propranolol also decreased heart rate during coronary occlusion and produced similar improvement in marginal segment function; however, in contrast to morphine, there was depression of contraction in the control segments. Nitroglycerin given during coronary occlusion caused decreases in end-diastolic length of all segments and increased shortening in the marginal segment by 28%. Lidocaine administered during coronary occlusion produced a mild depression of myocardial function in all regions of the heart.
 ...
PMID:Regional Myocardial function in the conscious dog during acute coronary occlusion and responses to morphine, propranolol, nitroglycerin, and lidocaine. 81 13

Hemodynamic and electrocardiographic analysis during rapid right atrial stimulation was performed before and one, two, and four hours after oral application of longacting nitroglycerin (5 mg) and isosorbide dinitrate (20 mg) in 11 and 9 patients, respectively with coronary heart disease. Atrial stimulation without nitrate induced significant ischemic ST segment depression. Cardiac output showed a small decrease and the mean arterial, pulmonary artery, and pulmonary wedge pressure increased. Isosorbide dinitrate reduced the ischemic reaction by 40% from the first to the fourth hour after application. Cardiac output, stroke volume, aterial, pulmonary artery, and pulmonary wedge pressure also decreased continuously. Nitroglycerin caused a similar reduction of ischemic ST segment depression for two hours. Systolic, diastolic, and mean arterial pressure decreased significantly. Cardiac output, stroke volume, and pulmonary artery pressure remained unchanged. It was concluded that the applied dose of isosorbide dinitrate showed a more extensive longacting effect.
 ...
PMID:[Hemodynamic and electrocardiographic prolonged nitrate effect during frequency load in coronary disease]. 82 Jan 4

The effects of an intravenous infusion of nitroglycerin were studied in 20 acutely hypertensive patients during coronary-artery surgery. Eight patients had histories of essential hypertension and six had been treated for it. They were anesthetized with morphine, diazepam, N2O, O2, pancuronium, and enflurane. Control measurements were obtained after sternotomy. Nitroglycerin was then administered until the blood pressure returned to normal, and the measurements then repeated. The mean dose of nitroglycerin was 80.0 +/- 4.7 mug/min, or 0.96 mug/kg/min. This produced significant decreases (P less than .05) in systolic, diastolic, and mean arterial blood pressures, central venous pressure, pulmonary capillary wedge pressure, systemic vascular resistance, and left ventricular stroke work index. Cardiac index, stroke index, and heart rate were unchanged. Two indices of myocardial oxygen demand (rate-pressure product and tension-time index) were significantly decreased by nitroglycerin (P less than .005). Fifty per cent of the patients had improvement in ST-segment depression on the electrocardiogram. These findings demonstrate that nitroglycerin can be safely administered intravenously during operation, and suggest that nitroglycerin decreases myocardial oxygen demand and relieves myocardial ischemia.
 ...
PMID:Nitroglycerin infusion during coronary-artery surgery. 82 Feb 17

In patients ranked ASA 1, laryngoscopy and intubation lead to an average increase in blood pressure of 40 to 50%, and a 20% increase in heart rate. These changes, which are greatest one minute after intubation, last for 5 to 10 min. They are due to sympathetic and adrenal stimulation, which may also result in some arrhythmias. About half the patient with coronary artery disease experience episodes of myocardial ischaemia during intubation when no specific prevention is undertaken. Among the different means available for this, narcotics seem to have a reliable and constant effect, but they may be responsible for postoperative respiratory depression. The protective effect of fentanyl starts at 2 micrograms.kg-1, and is at a maximum at 8 micrograms.kg-1. Lidocaine is the drug used most. Recent studies have questioned its efficacy. In clinical practice, it is particularly effective in preventing the pressor response to tracheal intubation, whatever its route of administration (intravenous or intratracheal), but not the increase in heart rate. Beta blockers with bradycardic, antihypertensive, antiarrhythmic and antiischaemic properties, have been advocated. As opposed to lidocaine, these agents are more effective in preventing the changes in heart rate than the pressor response. Because of their depressor effect on the myocardium, their place still remains to be defined, especially in the cardiac risk patient. Short-acting beta blockers should be preferred. Nitroglycerin is specifically indicated in coronary artery disease. Other agents, such as clonidine or calcium blockers, seem to be less effective or less convenient in preventing the haemodynamic alterations. In clinical practice, prevention will first rely on a sufficient dose of narcotics. In some cases, nitroglycerin or beta blockers may be used so as to decrease the doses of narcotics, without altering their efficacy; however, the risk of hypotension should be constantly borne in mind. If preventing measures have not been taken, short-acting antihypertensive agents (beta blockers, calcium blockers) should be used in patients who develop major hypertension during laryngoscopy and intubation.
 ...
PMID:[Consequences and prevention methods of hemodynamic changes during laryngoscopy and intratracheal intubation]. 135 16

Endothelium-dependent relaxation is depressed in the femoral artery of dogs with heartworm, Dirofilaria immitis, infection. Moreover, in infected dogs, the mechanism of relaxation is different. Because D. immitis is located primarily in the pulmonary circulation, these findings suggested that D. immitis releases biologically active mediators that alter distal endothelium-dependent relaxation. We tested this hypothesis in vitro. Rings of rat aorta were exposed to D. immitis (alone, in 1,000 mol wt or 100 mol wt cutoff dialysis tubing, and bioassay with conditioned medium). D. immitis alone depressed relaxation to acetylcholine, carbachol, and A23187. Nitroglycerin relaxation was not affected. Depression of acetylcholine relaxation was seen with D. immitis alone, in 1,000 mol wt dialysis tubing, and bioassay with conditioned medium. However, acetylcholine relaxation with D. immitis in 100 mol wt dialysis tubing was not different from control. It appears that D. immitis releases a small, stable, biologically active factor that alters endothelium-dependent relaxation. Its exact nature is unknown. The study of endothelial cell behavior in filariasis and modulation of endothelial cell function by filarial factors may provide important clues in understanding the pathogenesis of parasitic diseases.
 ...
PMID:Depression of endothelium-dependent relaxation by filarial parasite products. 211 4

To investigate the antianginal action of nitroglycerin and nifedipine, systemic and right heart pressures, cardiac output, oxygen consumption, and radionuclide left ventricular ejection fraction and volume were measured in 14 men with stable effort angina and a positive exercise electrocardiogram. Exercise tests were performed on a semiupright bicycle ergometer on no therapy and after intravenous nitroglycerin and sublingual nifedipine, which lowered mean arterial pressure by 20 mm Hg. Exercise tolerance improved from 50 +/- 4 to 61 +/- 5 W on nifedipine and to 79 +/- 4 W on nitroglycerin (p less than 0.01, nitroglycerin vs. nifedipine). At submaximal workloads, both drugs decreased arterial pressure and ventricular volumes, but heart rate was higher on nifedipine. At peak exercise on nitroglycerin (79 W), oxygen consumption, cardiac index, heart rate, and rate-pressure product were significantly increased over peak control and nifedipine values, while systolic pressure and end-diastolic volume were unchanged. Nitroglycerin reduced pulmonary wedge pressure more and systemic diastolic pressure less than nifedipine, so the coronary perfusion gradient was reduced by nifedipine and maintained by nitroglycerin. Also, there was less angina and ST-segment depression after nitroglycerin compared to control or nifedipine, and the left ventricular diastolic pressure-volume relationship was improved only by nitroglycerin. This suggests that the action of nitroglycerin in reducing ischemia is not only due to reduced myocardial oxygen demand, but that myocardial oxygen delivery may also be increased.
 ...
PMID:Comparison of the effects of nifedipine and nitroglycerin on hemodynamic determinants of myocardial oxygen consumption and supply during exertional angina. 247 80

In 24 patients (pts) with proven coronary artery disease, stable angina pectoris (AP) and elevated pulmonary artery pressure (PAP) during bicycle exercise, the acute and chronic (4 and 8 months) effects of several long-acting nitrates in different dosages: 50-300 mg pentaerythrityltetranitrate (PETN) or 40-120 mg isosorbide dinitrate (ISDN) were evaluated in comparison to sublingual nitroglycerin. Nitroglycerin was about 30%-40% more effective than PETN and ISDN with regard to pulmonary artery pressure at exercise. Beneficial effects of both long-acting nitrates were shown with regard to the number of anginal attacks, nitroglycerin consumption, and ST-segment depression both during short- and long-term treatment. Both nitrates decreased exercise pulmonary artery pressure by 15%-20%, at acute testing and during chronic therapy. There was no difference with respect to the long-term effects of both long-acting nitrates. However, more side-effects were observed during ISDN treatment. There were no signs of nitrate tolerance development with the therapy schedules under investigation.
 ...
PMID:[Long-term effect of various nitrates in ischemic heart disease and latent heart failure]. 251 96


1 2 3 4 Next >>