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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of nitroglycerin and sodium nitroprusside on arterial and venous blood gases and acid-base state as well as central hemodynamic parameters were assessed in myocardial infarction patients using a micro-Astrup and a rheoplethysmograph. Blood oxygen flow and oxygen uptake were estimated. Nitroglycerin and sodium nitroprusside, administered to myocardial infarction patients showing no signs of heart failure, caused a significant reduction in arterial blood partial oxygen pressure (pO2), which, however, did not lead to a reduction of oxygen flow and tissue oxygen provision. In myocardial infarction patients with heart failure, nitroglycerin and sodium nitroprusside had a favorable effect on systemic oxygen regimen and central hemodynamics.
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PMID:[Effect of peripheral vasodilators on the oxygen system of the body and central hemodynamics in patients with acute myocardial infarction]. 314 56

We performed a double-blind controlled crossover trial of perhexiline maleate versus identical placebo in daily doses of 100-400 mg in 20 male patients who were severely limited with angina pectoris despite therapy with beta-adrenoreceptor blockers. All patients had documented coronary artery disease and were awaiting coronary artery bypass grafting. Beta-blocker therapy was continued unchanged. A significant response compared to placebo was evident after 100 mg of perhexiline, and incremental therapeutic effects were evident up to 400 mg. The mean weekly angina rate fell from 18.2 +/- 2.8 basal to 6.2 +/- 1.5 on 200 mg (P less than 0.05) to 2.8 +/- 0.9 on 400 mg perhexiline (P less than 0.05). Nitroglycerin consumption fell in parallel. The mean exercise duration increased from 261 +/- 57 sec to 384 +/- 75 sec (P less than 0.05). Five patients became asymptomatic on perhexiline, and the number of pain-free days increased 100% (P less than 0.01) compared to placebo. No patient experienced hypotension or heart failure. This study shows that the addition of perhexiline to beta-adrenoreceptor antagonists in patients with severe angina pectoris is effective and represents an alternative therapy.
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PMID:Antianginal efficacy of perhexiline maleate in patients refractory to beta-adrenoreceptor blockade. 613 84

Nitroglycerin (NTG) in a transdermal therapeutic system (TTS) was evaluated in 16 patients with severe chronic heart failure. Eight patients were given NTG TTS with an in vivo release rate of 5 mg/24 h. No significant changes in heart rate or blood pressure were observed. Pulmonary capillary wedge (PCW) pressure was reduced significantly from a control value of 29 +/- 4 mm Hg to 17 +/- 2 mm Hg after 1 h (p less than 0.01), and significant reduction was maintained for 24 h. The system was then removed and PCW pressure rose to 27 +/- 2 mm Hg after 2 h. NTG TTS, 10 mg/24 h, was applied and PCW pressure was again reduced significantly. Significant reduction in systemic vascular resistance and increases in cardiac and stroke volume indices occurred on the first day at 4 h but were not maintained. In another eight patients, the haemodynamic effects of NTG TTS (5 mg/24 h), oral isosorbide dinitrate (20 mg), and topical NTG ointment (1 inch) were compared. Significant reductions in PCW pressure were achieved with each method of treatment, but no significant alterations in other haemodynamic measurements were observed. Haemodynamic reevaluation of 10 patients treated with NTG TTS for 3 months showed partial attenuation of the reduction in PCW pressure compared with the initial response.
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PMID:Nitroglycerin in a transdermal therapeutic system in chronic heart failure. 619 16

The effect of nitroglycerin combined with methoxamine in reducing infarct weight was studied in conscious dogs. Ten minutes after permanent left anterior descending (LAD) coronary artery occlusion, 10 dogs received nitroglycerin (450 micrograms bolus IV, then 300 micrograms/min for 4 hours) and methoxamine as needed to maintain blood pressure and heart rate. No dogs in heart failure. Ten control dogs received saline solution. Dogs were sacrificed 3 days later. The region at risk of infarction was delineated by simultaneously perfusing the aortic root with Evans blue and the distal LAD artery with saline solution under equal pressures. Slices of stained hearts were incubated with tetrazolium to identify infarct. Total weight of left ventricle (LV), risk region, and infarct was measured. Nitroglycerin-treated dogs showed no difference from control dogs in infarct weight (26.2 +/- 5.9 gm +/- SE vs 27.7 +/- 5.6 gm), percent risk region/LV (36.0 +/- 1.4% vs 37.9 +/- 3.1%), or present infarct/LV (23.5 +/- 5.2% vs 24.8 +/- 4.9%). In a subgroup with risk region/LV less than or equal to 35%, nitroglycerin reduced infarct weight by 45% (8.8 +/- 8.5% vs 15.9 +/- 7.9%), percent infarct/LV by 49% (7.1 +/- 6.8% vs 13.8 +/- 6.6%), and percent infarct/risk region by 41% (23.0 +/- 22.0% vs 38.9 +/- 15.9%). Because of the small number of dogs in the study, differences were not significant. In dogs with risk region/LV greater than 35%, nitroglycerin had no effect. Thus, in dogs without overt heart failure, nitroglycerin may salvage ischemic tissue within small areas at risk of infarction, but the results are not definitive. However, our results clearly demonstrate that in the absence of failure, nitroglycerin does not reduce the size of large infarcts.
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PMID:The effects of nitroglycerin-methoxamine combination on infarct size in conscious dogs. 640 71

Nitroglycerin, when administered to patients with heart failure, causes a marked reduction in left ventricular filling pressure but often an increase in stroke volume and stroke work; based on the Frank-Starling principle, such a reduction in "preload" would be expected to result in a decrease in left ventricular end-diastolic volume and, therefore, a decline in stroke volume. Assessment of pressure-volume coordinates, however, has revealed that nitroglycerin produces a downward shift in the pressure-volume relationship. This apparent improvement in left ventricular compliance cannot be attributed to alterations in the elastic properties of the myocardium but rather appear to reflect a reduction in left ventricular external constraint. Recent animal and clinical investigations in our laboratory suggest that nitroglycerin causes venous dilatation (particularly in the mesenteric bed), thereby decreasing venous pressure at any given vascular volume. This decrease in cardiac filling pressure results in a decrease in heart size and, therefore, a reduction in pericardial pressure. Left ventricular transmural (intracavitary minus pericardial) pressure is little changed, however, so that end-diastolic volume and stroke volume are maintained.
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PMID:Mechanism of action of nitrates. Role of changes in venous capacitance and in the left ventricular diastolic pressure-volume relation. 643 73

Nitroglycerin is absorbed in vitro into polyvinyl chloride tubing, and it has been recommended that nitroglycerin be administered intravenously through specialized polyethylene infusion sets. To determine if tubing type is essential to achieve physiologic effectiveness, we studied dose responses to intravenous nitroglycerin in 15 patients with heart failure using standard polyvinyl chloride tubing in seven (group 2) and special polyethylene infusion sets in seven (group 1) (one patient was excluded from analysis because of technical difficulties). We monitored heart rate, blood pressure, right atrial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac output. Cardiac index, systemic and pulmonary vascular resistance, triple index, rate pressure product, stroke volume, stroke volume index, and stroke work index were calculated. Baseline and treatment measurements were obtained from five to 15 minutes after the infusion of 10, 20, 40, and 80 micrograms of nitroglycerin per minute. Over-all, systolic blood pressure decreased (p less than 0.05) about 8 percent and mean blood pressure approximately 12 percent, mean pulmonary artery pressure and mean pulmonary capillary wedge pressure decreased 30 to 40 percent, and the decline in mean right atrial pressure was 35 percent of baseline (all p less than 0.05). Heart rate and cardiac index did not change (p greater than 0.05). Pulmonary vascular resistance decreased slightly (p = 0.07) and systemic vascular resistance significantly (p less than 0.05). When the two groups were compared physiologic changes were virtually identical (p less than 0.05). Two-way analysis of variance for baseline corrected data proved no differences between tubing sets (p less than 0.05), but the infusion concentration rate was highly related to response (p = 0.0001). A significant (p less than 0.05) decrease in mean blood pressure and mean right atrial pressure was noted at lower dose rates (20 micrograms per minute and 40 micrograms per minute, respectively) in group 1. Beneficial hemodynamic effects in heart failure patients can, then, be predicted to occur at 80 micrograms per minute infusion rates; these responses seem independent of the type of infusion tubing system employed. Additionally, when patients given intravenous nitroglycerin for various reasons were followed for 48 hours, the majority receiving infusions via polyvinyl chloride tubing (group 2) did not require dosage adjustments. Also, at lower flow rates, more solution than calculated may be delivered when polyethylene tubing infusion sets are employed with volumetric infusion pumps.
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PMID:Specialized delivery systems for intravenous nitroglycerin. Are they necessary? 643 75

Vasodilator therapy has not been effective in patients with pulmonary hypertension because most of the drugs that have been utilized in treating this disorder do not exert selective effects on the pulmonary circulation. Nonselective agents may cause predominant systemic vasodilation and lead to severe hypotension; they may elicit reflex activation of the sympathetic nervous system and further elevate pulmonary artery pressures; or they may exert depressant effects on right ventricular function and aggravate right-sided heart failure. Nitroglycerin has theoretic appeal as a vasodilator drug in patients with pulmonary hypertension because it exerts a direct effect on the pulmonary circulation in doses that do not affect systemic resistance vessels or the myocardium and do not activate neurohumoral reflexes. Furthermore, the drug uniquely reduces pulmonary artery pressures in addition to pulmonary vascular resistance due to its ability to dilate venous capacitance vessels. Preliminary studies with sublingual and intravenous nitroglycerin in patients with pulmonary hypertension have shown that the drug produces marked hemodynamic improvement and that clinical benefits follow long-term therapy with transcutaneous or oral nitrates. However, treatment may provoke hypotensive events in some patients and systemic hypoxemia in others; still others may fail to benefit because the pulmonary vasculature is unresponsive to any vasodilator stimulus. Further work is needed to define the benefits and risks of nitroglycerin therapy in patients with pulmonary hypertension.
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PMID:Nitroglycerin therapy in the management of pulmonary hypertensive disorders. 643 80

Nitroglycerin ointment (NTGO) was applied to the precordial area in 88 patients with heart failure arising from acute myocardial infarction (AMI) or other types of heart disease, and its effects on hemodynamic parameters were determined. After NTGO was applied, patients' systolic blood pressure (P less than 0.001), double product (heart rate X systolic pressure, P less than 0.001), pulmonary capillary wedge pressure (P less than 0.001), and systemic vascular resistance (P less than 0.001) decreased significantly. These changes began 30 to 60 minutes after NTGO was applied and lasted two to six hours. Based on these hemodynamic changes, we conclude that NTGO is beneficial for patients with heart failure due to AMI or other heart disease.
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PMID:Multicenter studies of 2% nitroglycerin ointment in patients with heart failure. 643 84

The clinical and hemodynamic effect of nitrates with both their single administration and a prolonged therapy in patients with atrioventricular block related to elecrocardiostimulation has been studied. Nitroglycerin has been found to exercise its action in two phases: first decreasing and then increasing cardiac output. The character of phase I has been ascertained to correlate with the potential development of various complications during the treatment with nitrates. A conclusion has been drawn as to the efficacy of nitrosorbid employment in the multiple modality treatment of chronic cardiac insufficiency in patients with an implanted cardiostimulator.
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PMID:[Effect of nitrates on cardiodynamics in patients with atrioventricular block treated by electrocardiostimulation]. 643 86

The peripheral venodilation, principal effect of NTG and nitrates may cause a significant reduction in pulmonary venous pressure and, therefore, improve the symptoms of pulmonary venous congestion. Hemodynamic effects o high doses of oral isosorbide dinitrate in patients with chronic heart failure (N - 13). (Formula: see text). The other mechanism by which nitrates can potentially improve cardiac performance in patients with heart failure due to obstructive coronary artery disease is by relieving myocardial ischemia which tends to improve global myocardial function. Nitroglycerin or nitrates improve systolic motion of the ischemic but viable myocardial segments improved segmental wall motion consequent on relief of regional myocardial ischemia is probably related to a decrease in the determinants in oxygen demand rather than an increase in regional myocardial blood flow. An increase in collateral blood flow, however, may be contributory. Effects of nitrates on coronary dynamics and myocardial metabolism. (Formula: see text). These findings suggest with nitrates cardiac performance improves with decreased metabolic cost.
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PMID:Hemodynamic effects of nitrates in chronic heart failure and myocardial infarction. 677 91


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