Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of intravenous (IV) nitroglycerin (NTG) on perioperative myocardial ischemia as detected by single pass radionuclide angiocardiography was studied in 20 patients scheduled for elective coronary artery bypass grafting (CABG). Ten patients, selected at random, received IV NTG 1 microgram.kg-1.min-1 (NTG group) and 10 others, IV saline (control group). Anesthetic induction consisted of midazolam 0.2 mg.kg-1, vecuronium 0.1 mg.kg-1, and 50% N2O in O2. ECG leads I, II, and V5 were monitored for ST segment changes. Single pass radionuclide angiocardiography (RNA) was performed at 5 times: prior to induction, prior to tracheal intubation, and at 1, 3.5, and 6 min following intubation. The presence of new regional wall motion abnormalities (RWMA) was determined from each RNA study as compared with the preinduction measurement. Apart from one patient in the control group who developed a new "v" wave after intubation, there was no evidence of ischemia by pulmonary capillary wedge pressure. No ECG evidence of ischemia was detected in any patient. Despite this, new regional wall motion abnormalities were observed in 3 patients in the control group and 1 patient in the NTG group. Blood pressure and heart rate responses of patients with new RWMA were not significantly different from other patients. The low incidence of ischemia in this population precludes a definitive statement regarding the efficacy of IV NTG, but the lower incidence of RWMA in the NTG group suggests a protective effect.
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PMID:The effect of nitroglycerin on response to tracheal intubation. Assessment by radionuclide angiography. 250 40

Recent information has suggested that early diastolic filling may be influenced by the left ventricular filling pressure, especially in the failing left ventricle. Acute severe left ventricular dysfunction was induced in 14 dogs by severe left ventricular global ischemia produced by left main coronary artery microsphere embolization until the left ventricular end-diastolic pressure was greater than or equal to 20 mm Hg. To assess the importance of left ventricular filling pressure on left ventricular diastolic filling, nitroglycerin was infused and titrated to reduce left ventricular end-diastolic pressure to less than 15 mm Hg in seven dogs, whereas the remaining seven dogs were observed for 1 h after acute severe left ventricular dysfunction. In both groups of dogs, severe left ventricular dysfunction resulted in left ventricular dilation and elevation of end-diastolic pressure, reduction in area ejection fraction (echocardiographically determined) and an early redistribution of diastolic filling (increased filling fractions at one-third and one-half diastole) despite prolongation of the time constant of left ventricular pressure decline. Pressure-area plots shifted upward and rightward with severe left ventricular dysfunction and were unchanged at 1 h as were all other variables. Nitroglycerin infusion reduced left ventricular size and filling pressure, redistributed diastolic filling to later in diastole as characterized by reduced filling fraction at one-third diastole (left ventricular dysfunction 48.8 +/- 9.7%, nitroglycerin 17.9 +/- 7.9%, p less than 0.001) and shifted downward left ventricular pressure-area plots. Nitroglycerin also improved the time constant of relaxation (left ventricular dysfunction 83 +/- 15 ms, nitroglycerin 52 +/- 15 ms, p less than 0.001) and lengthened the diastolic filling period.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of nitroglycerin-induced reduction of left ventricular filling pressure on diastolic filling in acute dilated heart failure. 250 Apr 71

To determine the effects of intravenous nitroglycerin on the velocities and excursions of the acutely ischemic myocardium, 20 open-chest dogs were studied by use of ultrasound. In 10 dogs with acute septal ischemia, the posterior wall excursion during contraction (B-C excursion), the mean systolic posterior wall velocity, and the posterior wall excursion remained unaltered. Nitroglycerin, however, increased all these parameters (P less than 0.01). In 10 dogs with acute posterior wall ischemia the B-C excursion (aneurysmal bulging) increased (P less than 0.01), but the mean systolic posterior wall velocity and posterior wall excursion decreased (P less than 0.01). Nitroglycerin increased even more the aneurysmal bulging (P less than 0.01) and the other parameters (P less than 0.01). Increased regional blood flow, reduced afterload, and mechanical pulling of the ischemic myocardium seem to be a possible mechanism. The measurements were obtained using the recently described method of the specific points.
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PMID:Left ventricular excursions and velocities during coronary arterial ligation. Effects of nitroglycerin infusion in an experimental model. 250 12

Elevation of extracellular osmolality reduces the extent of myocardial and endothelial cell swelling that accompanies acute ischemia, and the reduction of cell swelling is associated with an increase in collateral blood flow to the ischemic area. However, little is known about the effects of hyperosmolality on the vascular resistance of the collateral coronary vasculature. We compared the effects of hyperosmolar mannitol with those of nitroglycerin and dipyridamole on the vascular resistance of large collateral coronary vessels and of the small arterial vasculature in an isolated heart model of regional ischemia. Elevation of osmolality by mannitol increased collateral blood flow to the ischemic region through at least two mechanisms. First, increasing osmolality resulted in dilation of large arterial conductance vessels, similar to that produced by nitroglycerin. In addition, mannitol produced an effect on the coronary circulation at a microvascular level which, per se or in combination with its effect on larger collateral conductance vessels, increased collateral blood flow to ischemic regions.
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PMID:Hyperosmotic mannitol and collateral blood flow to ischemic myocardium. 250 18

We treated a neonate with two sites of ischemia caused by dopamine extravasation. Standard treatment called for local infiltration of phentolamine, an alpha blocker. Instead, we applied 2% topical nitroglycerin ointment and the ischemia was totally reversed.
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PMID:Reversal of dopamine extravasation injury with topical nitroglycerin ointment. 251 Feb 8

The effect of the new antianginal drug, nicorandil, was studied in several models of myocardial ischemia in anesthetized dogs. In animals subjected to an acute or chronic coronary artery occlusion, nicorandil produced increases in collateral perfusion when changes in aortic pressure were minimized. In a model of irreversible ischemia, nicorandil produced a marked (50%) decrease in myocardial infarct size. In several models of reversible ischemia-reperfusion injury, the "stunned myocardium," nicorandil was shown to enhance the recovery of systolic segment shortening after a brief period (15 to 30 minutes) of coronary occlusion. Other vasodilators such as nitroglycerin or nifedipine were not as efficacious as nicorandil. In a model of multiple (n = 3) coronary occlusion (5 minutes) with intermittent (30 minutes) reperfusion, nicorandil improved the recovery of systolic segment shortening during reperfusion and prevented the loss of adenosine triphosphate and tissue edema that occurred in untreated hearts. The beneficial effects of nicorandil on functional and metabolic recovery after recurrent ischemia was shown to be partially the result of an energy-sparing effect of nicorandil to reduce free fatty acid use during the ischemic period. Cyclooxygenase blockade with indomethacin did not block the beneficial effects of nicorandil in the stunned myocardium. These results suggest that nicorandil does not promote an increase of prostacyclin. Finally, nicorandil was found to inhibit superoxide anion production by human neutrophils stimulated by formyl-methionyl-leucyl-phenylalanine plus cytochalasin B. These results suggest that part of the beneficial actions of nicorandil may occur during reperfusion and may be the result of a reduction in oxygen free radical production.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of nicorandil on coronary circulation and myocardial ischemia. 252 19

It has been suggested that coronary artery bypass grafting (CABG) performed in the setting of emergent failure of percutaneous transluminal coronary angioplasty causes minimal increased risk compared with routine CABG. We reviewed the records of 103 patients undergoing emergency CABG for failed percutaneous transluminal coronary angioplasty (group 1) and compared them with an identical number of consecutive CABG patients from 1987 (group 2). Group 1 had a lower risk profile evidenced by lower mean age (p less than 0.01), fewer diseased vessels (p less than 0.0001), better ventricular function (p less than 0.001), fewer left main lesions (p less than 0.0001), and fewer patients with acute ischemia requiring intravenous administration of nitroglycerin (p less than 0.01). Despite these differences, the group 1 patients had a higher mortality rate (11% versus 1%; p less than 0.01) and a higher rate of perioperative infarctions (new Q wave) (22% versus 6%; p less than 0.01). An analysis of risk factors was performed in the group 1 patients using 36 preoperative and operative variables. Multivariate analysis revealed that left ventricular score (p less than 0.0001), preoperative (after percutaneous transluminal coronary angioplasty) need for inotropic support (p less than 0.005), and age (p less than 0.025) were independent predictors of operative mortality. In conclusion, emergency CABG after failed percutaneous transluminal coronary angioplasty carries a significantly greater risk of operative death and perioperative infarction than elective CABG.
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PMID:Emergency coronary artery bypass grafting for failed angioplasty: risk factors and outcome. 252 16

The effects of the synthetic 28-amino-acid alpha-human atrial natriuretic peptide (ANP) on the proximal coronary arteries and coronary blood flow were evaluated in 17 patients. Proximal coronary dimension was quantitated by digital angiography, and coronary flow was quantitated with 3F Doppler flow catheters. ANP, when given as a 2.5-micrograms/kg bolus in the left ventricle, caused sustained significant proximal coronary dilations from 3.49 +/- 0.57 to 4.09 +/- 0.76 mm, lasting more than 30 minutes. The proximal coronary diameter did not increase further after intracoronary injection of 0.3 mg nitroglycerin (4.08 +/- 0.79 mm). Coronary flow (resistance coronary dilation) was not significantly increased at 5 minutes after ANP (87 +/- 55 to 102 +/- 54 vol flow units), indicating that the proximal coronary dilations were not flow dependent. The persistent proximal coronary dilations were associated with minor and transient decreases in aortic pressure and left ventricular end-diastolic pressure and with minor and transient increases in heart rate, cardiac output, and left ventricular contractility. Plasma ANP level increased significantly by more than sixfold from 39.8 +/- 8.8 to 245.8 +/- 168.5 pg/ml. The time course of proximal coronary dilations was related more closely to the time course of increase in plasma cyclic guanosine monophosphate than that of plasma ANP. This study demonstrates that bolus injection of ANP (2.5 micrograms/kg), an endogenous vasodilator, caused marked sustained preferential proximal coronary dilations and brief minor changes in cardiac and systemic hemodynamics. Although additional studies are needed to assess its clinical efficacy as a coronary dilator in the treatment of coronary artery disease, these data suggest a potential of ANP in the therapy of ischemia.
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PMID:Effects of atrial natriuretic peptide on the coronary arterial vasculature in humans. 255 73

This is the first reported large clinical trial of the antianginal and acute ischemic effectiveness and safety of dilevalol (the R, R-isomer of labetalol) in patients with chronic stable angina pectoris. This was a multicenter double blind fixed-dose parallel group placebo controlled trial. Patients with chronic stable angina and positive and reproducible exercise tests (+/- 20%) were included. If randomized, patients entered one of four fixed dose groups (twice a day placebo, 100 mgm, 200 mgm and 400 mgm bid for 2 weeks). Exercise testing was performed at 2 hours (peak) and 12 hours (trough) postdosing. This was followed by a 2-week once-a-day dosing regimen in which patients received the same total daily dose as the prior 2 weeks, with the full dose in the morning and a matched placebo in the evening. Exercise testing was performed at 2 hours (peak) and 24 hours (trough) postdosing. Anginal frequency and NTG consumption were significantly reduced, and equally so, by qd and bid regimens. The time of exercise to the onset of angina increased and the proportion of patients terminating exercise because of moderate angina decreased in a dose response fashion for both peak and trough tests and for both qd and bid regimens. There was also a dose related decrease in exercise induced ST segment depression and an increase in time to 1 mm ST depression. In 15 patients, 24-hour ambulatory monitoring also revealed a decrease in episodes of silent ischemia. No significant side effects related to the study drug occurred.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The efficacy and safety of dilevalol in patients with chronic stable angina pectoris. 257 29

A new transdermal system (BIO TSD) containing the beta-adrenergic blocker mepindolol was assessed in a placebo controlled clinical trial in 12 patients with coronary heart disease. On therapy, the number of anginal attacks and the consumption of oral nitroglycerin (glyceryl trinitrate) were reduced significantly. During ergometer exercise the exercise tolerance was improved and the ischemic ST-segment depression was reduced significantly. Holter monitoring revealed significant reductions of the number of manifest and silent episodes and the total duration of ischemia. No relevant side effects were observed.
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PMID:[Anti-ischemic action of the transdermally applied beta-receptor blocker, mepindolol in patients with stable angina pectoris]. 257 3


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