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

Phosphodiesterase III (PDEII) inhibitors as so-called inodilators have previously proven a valuable alternative to positive inotropes in patients with cardiac insufficiency. In this study we compared patients receiving piroximone (P, n = 14, 0.5-mg/kg bolus in 30 min and then 3-6 micrograms/kg/min) with enoximone patients (E, n = 13, 1-mg/kg bolus and then 4-20 micrograms/kg/min) and with a third group (D, n = 14) receiving a combination of dopamine (4-10 micrograms/kg/min) and glyceroltrinitrate (0.5-5 micrograms/kg/min) for hemodynamic support. All three groups were comparable in terms of age, body surface area, and preoperative cardiac function [cardiac index (CI) less than or equal to 2.5 L/min/m2, LAP greater than 15 mm Hg]. Hemodynamic measurements (10) and Holter monitoring were performed until 18 h post MVR. In all groups, epinephrine was used for additional inotropic therapy if mean arterial pressure (MAP) was less than 60 mm Hg and/or CI was less than 2.5 L/min/m2. There was no early or late postoperative mortality in either group. Continuous support with epinephrine was necessary in 8 patients in group D, whereas initially 8 patients in group E and 6 patients in group P required epinephrine support. After PDE III inhibitor infusion, 2 patients in group E and 2 patients in group P remained epinephrine dependent (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparison of enoximone and piroximone in patients after mitral valve operation: a prospective and controlled clinical study. 137 6

High levels of endogenous plasma catecholamines in patients with severe congestive heart failure induce a down-regulation of the myocardial beta-adrenoreceptors and thus cause adrenoreceptor agonists, such as dobutamine, to be less effective in the treatment of these patients. Phosphodiesterase III inhibitors work independent of adrenoreceptor activity and plasma catecholamine levels; thus these agents are likely to be more effective in the treatment of severe heart failure. The present study compares both the initial and late hemodynamic effects of dobutamine and milrinone during sequentially administered 24-hour infusions. Twenty patients with severe heart failure (New York Heart Association class III, n = 4; New York Heart Association class IV, n = 16) were investigated. Dobutamine could be administered at the prescribed maximum dose of 15 micrograms/kg/min for 24 hours in only 15 of 20 patients. In three patients the dose was reduced or dobutamine infusion completely stopped because of a drug-related increase in heart rate greater than 140 beats/min. Another 2 of 20 patients showed no hemodynamic improvement over 3 hours at the maximum dose of 15 micrograms/kg/min. Dobutamine administration was also discontinued in these patients on account of the existing unfavorable hemodynamic condition, and therapy with intravenous milrinone was started. All 20 patients responded to milrinone without side effects, although comparison of the hemodynamic effects during a 24-hour infusion was possible in only 15 patients. The 15 patients studied over both observation periods experienced an increase in heart rate from 88.8 to 105.6 beats/min (+ 1 hour; p less than or equal to 0.001) when receiving dobutamine but had no increase with milrinone. Stroke volume increased during dobutamine infusion from 19.3 to 28.9 ml/m2 (+49.6%) after 1 hour and then fell continuously to 25.2 ml/m2 after 12 hours; during milrinone therapy, stroke volume increased from 18.8 to 31.2 ml/m2 (+66%; p less than or equal to 0.001) and remained at this level until the end of the infusion (30.2 ml/m2). Pulmonary capillary wedge pressure (PCWP) decreased (p less than or equal to 0.001) immediately during milrinone therapy from 26.5 to 16.2 mm Hg after 30 minutes and stabilized at 20.1 mm Hg after 24 hours. During dobutamine infusion PCWP showed a delayed decrease from 27.8 to 19.0 mm Hg after 6 hours and subsequently rose to 22.7 mm Hg after 24 hours.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Phosphodiesterase III inhibition or adrenoreceptor stimulation: milrinone as an alternative to dobutamine in the treatment of severe heart failure. 185 90

More and more patients with coronary heart disease (CAD) are admitted to intensive care units. The drugs used to treat these patients have various effects on the myocardium which must be known in order to avoid worsening the CAD. This review examines the metabolic effects on the myocardium of the most commonly used drugs in intensive care. The physiology of myocardial oxygen supply is first recalled with regard to the coronary circulation, myocardial oxygen extraction and consumption. Digitalis glycosides do not affect the coronary circulation, but the decrease myocardial oxygen consumption in patients with heart failure, mainly by lowering heart rate. Dihydropyridine calcium blockers (nifedipine, nicardipine) increase coronary blood flow, despite a decrease in arterial blood pressure. Their effects on myocardial oxygen consumption are mediated by a sympathetic reflex. Verapamil decreases the heart rate and myocardial inotropism, and is responsible for coronary vasodilation. The result is a decrease in myocardial oxygen consumption. Diltiazem and bepridil have almost similar effects: they decrease myocardial oxygen consumption and increase blood supply to the heart. It has been recently shown that verapamil was the most depressant calcium channel blocking agent, and that it resulted in the most important decrease in myocardial metabolism. Beta-blocking agents decrease myocardial metabolism, except those with an important intrinsic sympathomimetic activity, such as pindolol. Amiodarone can be considered as an alpha and beta blocking drug: its main effect is to counteract the effects of endogenous catecholamines on myocardial metabolism. The sympathomimetic amines (noradrenaline, adrenaline, isoprenaline, dopamine, dobutamine) increase, to different extents, myocardial oxygen consumption. Vasodilators, such as the nitrates or sodium nitroprusside, decrease cardiac filling pressures, and increase myocardial blood flow, thus lowering myocardial oxygen consumption. Phosphodiesterase inhibitors (amrinone, enoximone) have both an inotropic and a vasodilating effect. They decrease cardiac afterload, and increase blood supply to the myocardium; this compensates for the increase in myocardial oxygen consumption due to the increase in myocardial contractility. Because all the drugs used in intensive care have different effects on myocardial metabolism, their reasoned use should avoid an inappropriate increase in oxygen demand.
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PMID:[Changes in myocardial metabolism induced by drugs used during intensive care]. 197 Apr 63

Phosphodiesterase inhibitors that are selective for cAMP-specific cardiac and vascular PDE III comprise a new group of agents for the treatment of heart failure, which at present are limited to clinical shortterm intravenous use and research uses only. Although both intravenous amrinone and milrinone are FDA approved, only amrinone is available for general clinical use. Selective phosphodiesterase inhibition produces beneficial actions of positive inotropy and peripheral vasodilation that result from increased cardiac and vascular muscle concentrations of intracellular cAMP and ionic calcium. In addition, a positive lusitropic action (enhancement of cardiac relaxation) has been observed. Neither beta-adrenergic agonist activity nor inhibition of the sodium-potassium ATPase is produced by these agents. The magnitude of hemodynamic improvement generally exceeds that of the cardiac glycosides and is comparable with that of intravenous catecholamines such as dobutamine. The different pharmacodynamic profile of the PDE inhibitors is additive to the effects of cardiac glycosides, complementary and synergistic to the actions of catecholamines, and has been shown to have favorable effects on coronary hemodynamics. As a result there is continued enthusiasm for the short-term intravenous use of amrinone and potentially milrinone in the setting of acute heart failure resulting from systolic dysfunction (after myocardial infarction, open heart surgery, or infectious or toxic myocarditis), heart failure resulting from right ventricular systolic dysfunction, and when patients with severe heart failure await cardiac transplantation. Initiation of treatment with an intravenous bolus followed by a maintenance infusion provides prompt increases in stroke volume and cardiac output and simultaneous reductions in right and left ventricular filling pressures and systemic vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Acute positive inotropic intervention: the phosphodiesterase inhibitors. 203 20

Low cardiac output in acute heart failure can result in a functional impairment of organs, when tissue hypoxia occurs and cardiogenic shock develops. To restore cardiac output, various forms of therapy can be considered. Fluid replacement is sometimes beneficial in acute situations where oedema can reduce effective plasma volume. Vasodilators are often contra-indicated in shock, when arterial pressure is usually low. Inotropic therapy consists primarily of the administration of adrenergic agents. Dopamine and noradrenaline can be indicated in severe hypotension, to maintain coronary perfusion. Dobutamine is the catecholamine of choice to increase myocardial contractility. However, decreased responsiveness of the myocardial receptors to adrenergic stimulation rapidly becomes an important limitation. Phosphodiesterase inhibitors represent an interesting option to increase contractility, also by increasing cyclic AMP levels in the myocardium. In this respect, the combination of phosphodiesterase inhibitors with adrenergic agents is attractive. The additional vasodilatory properties of these agents can contribute to the increase in cardiac output with limited risk of further reduction in arterial pressure. In 13 patients with cardiogenic shock persisting despite the use of adrenergic agents, the addition of enoximone, 0.5 mg/kg, resulted in significant increases in cardiac index and stroke volume index and a significant decrease in pulmonary artery balloon occlusion pressure without consistent change in mean arterial pressure. In 8 patients, a second infusion of 0.5 g/kg amplified these effects. All but one of these patients survived the episode of cardiogenic shock, and 5 patients were discharged alive. In some cases, even lower doses of enoximone resulted in dramatic increases in cardiac output and oxygen transport in patients already treated with dobutamine with limited success.
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PMID:The role of enoximone in the treatment of cardiogenic shock. 217 30

Recent advances in our knowledge of heart failure have shown that both a central and a peripheral factor are involved in this syndrome. Therefore, the ideal drug should combine the properties of a positive inotropic agent with those of a peripheral vasodilator; many drugs recently introduced into clinical practice have been shown to present both of these features, and the term "inodilators" has been used to characterize them. Inodilators can be further classified on the basis of their mechanism of action, i.e., phosphodiesterase inhibitors, and sympathomimetic and dopaminergic drugs. Phosphodiesterase inhibitors include bipyridine, imidazolone, and benzimidazole derivatives, which present potent inotropic and vasodilatatory actions. Despite their favorable acute effects, long-term studies have often yielded controversial, and sometimes disappointing, results as their chronic administration seems often to be associated with untoward effects and, above all, a poor prognosis. Sympathomimetic agonists act by stimulation of beta-receptors, with a consequent increase of myocardial contractility and peripheral vasodilation. Differently from the parenteral drugs (e.g., dobutamine), the oral agents present many important shortcomings including central nervous system effects, increased myocardial oxygen consumption, tachyarrhythmias, and, above all, development of tolerance during chronic administration. Dopaminergic drugs possess a unique pharmacologic profile since they add to the adrenergic stimulation their selective action on dopaminergic receptors. Dopamine is still one of the most useful drugs for the treatment of acute heart failure; the two oral drugs that more closely resemble its actions are levodopa and ibopamine. The administration of levodopa to patients with heart failure can induce a significant hemodynamic improvement that is maintained during chronic therapy. Ibopamine has been widely shown to cause a significant hemodynamic improvement in patients with heart failure. Its effects can be ascribed to a moderate increase of myocardial contractility accompanied by peripheral and renal vasodilatatory actions. This drug can also counteract some of the neurohumoral mechanisms (e.g., sympathetic stimulation and aldosterone secretion) that are activated in heart failure. These features can explain the favorable results that have also been recently obtained after the chronic administration of ibopamine.
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PMID:Clinical pharmacology of inodilators. 248 42

Phosphodiesterase inhibitors have vasodilating and positive inotropic properties, and these compounds may have energy saving effects due to vasodilation and energy consuming effects due to inotropism. In order to differentiate between the effects, it is necessary to relate myocardial oxygen consumption to its hemodynamic determinants. Myocardial oxygen consumption per beat was related to the following parameters: dp/dtmax, mean velocity of fiber shortening, pressure-volume work, peak developed wall stress, and stress-time integral. The best linear relationship was found between myocardial oxygen consumption per beat and the corresponding stress-time integral (r = 0.71; p less than 0.001) in patients with idiopathic dilative cardiomyopathy. Using i.v. nitroprusside as a pure vasodilator, myocardial oxygen consumption per beat and stress-time integral decreased along this established relationship. In contrast, the phosphodiesterase inhibitor enoximone given intravenously decreased the stress-time integral significantly more than the myocardial oxygen consumption per beat. We conclude from these data that phosphodiesterase inhibitors possess vasodilating properties which reduce the myocardial oxygen demand. In addition, they do have positive inotropic effects which increase the myocardial oxygen demand. Myocardial oxygen consumption always reflects the sum of both effects. The balance between the energy saving and the energy consuming effects may determine the efficacy of phosphodiesterase inhibitors, especially in the long-term treatment of chronic heart failure.
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PMID:Separation between vasodilation and positive inotropism by assessment of myocardial energetics in patients with dilated cardiomyopathy. 253 Sep 75

1. Cardiac failure is a clinical syndrome of symptoms and signs, which can be confirmed by imaging or invasive haemodynamic techniques. It may be caused by systolic or diastolic dysfunction, but systolic dysfunction rarely occurs alone. It is important to ascertain the degree to which each contributes, and the precise aetiology of the condition, particularly in relation to surgically correctable lesions. 2. Non-pharmacological approaches including weight loss, salt restriction and lifestyle changes may be beneficial in some patients, and diuretics, which reduce the load on the heart, are the traditional baseline therapy. 3. Digitalis has been used where problems with contractility predominate, but its beneficial effect has been disputed, and expectations of improvement in patients in sinus rhythm should not be too high. 4. Vasodilators have been considered as the next line of treatment. Arteriolar dilators tend to increase cardiac output, but have little effect on pulmonary artery wedge pressure, and venodilators tend to have the opposite effect. Probably both actions are necessary and angiotensin converting enzyme (ACE) inhibitors, which have both, have proved effective in terms of symptoms and survival. 5. Various other inotropic agents have been tried. Phosphodiesterase inhibitors improve exercise tolerance, but may increase the probability of serious arrhythmias, already a significant cause of sudden death. beta 1-partial adrenoceptor agonists such as xamoterol have shown some promise, and anti-arrhythmic therapy has also been considered. 6. Drugs which prevent progression of myocardial damage would prove a great advance, and beta-adrenoceptor antagonists and calcium channel blockers appear to have considerable potential in this area.
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PMID:Treatment of congestive heart failure--state of the art and future trends. 257 53

New agents for treating chronic heart failure include angiotensin converting enzyme (ACE) inhibitors, betablockers and phosphodiesterase inhibitors. The ACE inhibitors represent the major therapeutic advance of the 1980-1990 decade. This is the most effective class of drugs on survival, whatever the stage of heart failure and it shows the evolution towards symptoms in asymptomatic patients. Studies currently under way are evaluating the dose-effect relationship of ACE inhibitors. Betablockers improve the quality of life and physical performance but a benefit on mortality has not been shown in two recent trials. Phosphodiesterase inhibitors improve quality of life and physical performance at the price of an increase in mortality. Therefore, they are not indicated in the treatment of heart failure. However, new molecules such as vesnarininone or pimobendan are under trial. Finally, in the next few years, the introduction of antagonists to Angiotensin II receptors is eagerly awaited.
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PMID:[Treatment of chronic heart failure: current views]. 748 9

The analysis of currently used therapeutic targets provides considerable input in the choice of current and future therapies for dilated cardiomyopathy and congestive heart failure. Of the ion flux agents, a definitive answer concerning digoxin will soon be available. Currently, digoxin is likely of benefit to patients with persistent heart failure and significantly enlarged hearts despite therapy with preload and afterload reducing agents. Most currently available calcium channel blocking agents do not appear to be effective, although newer agents such as amlodipine and felodipine have yet to be adequately tested. Vesnarinone, which operates through the sodium and potassium rectifying channels and has limited phosphodiesterase inhibition, appears to provide a significant improvement in mortality and in symptoms. Part of the latter effect may be due to its anticytokine properties, which are currently being investigated. Analysis of vascular endothelial agents indicate that not all of the vasoactive agents improve survival, as demonstrated with prazosin and flosequinan. The dose of agents may be important, again demonstrating that less is better. Finally, those with additional effects, such as inositol triphosphate stimulation, may offer additional unique properties that may, in the future, provide benefit. Phosphodiesterase inhibitors are potentially beneficial in the short term but clearly should be avoided for long-term use. Lower doses of these agents are now being investigated, but the weight of evidence is against agents that operate primarily through phosphodiesterase inhibition. Renin angiotensin agents are the most efficacious of therapies available at this time. New angiotensin converting enzyme inhibitors are likely to add little to what is already known.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:New medical therapies for advanced left ventricular dysfunction. 779 29


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