Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sympathomimetic agents: isoproterenol (novodrin), dopamine, noradrenalin, adrenalin were used in 137 patients with acute circulatory insufficiency. Their hemodynamic effects were assessed, using catheterization of heart chambers and radiocardiography, and studies of circulating blood oxygen transport, acid-base state and metabolic product levels. A differential approach to sympathomimetic treatment has been developed. Isoproterenol is primarily indicated in those cases where myocardial failure is combined with decreased heart rate, conductivity disorders and markedly increased total peripheral resistance. Dopamine is more justified in cases where increasing the heart rate is more desirable, and there are signs of renal failure and heart rhythm disorders. The possibility of dopamine-induced pulmonary hypertension and pO2 fall should not be dismissed. Correct choice of an agent or a combination of agents makes it possible to control the patient's condition through action on various hemodynamic mechanisms that determine the magnitude of cardiac output.
 ...
PMID:[Use of sympathomimetic agents in the treatment of acute circulatory insufficiency in the immediate postoperative period of heart surgery patients]. 356 Jun 16

Long-term therapy with oral sympathomimetic amines in patients with heart failure has been limited by the eventual development of diminished pharmacologic efficacy. However, a previous investigation in five subjects with heart failure suggested that long-term ingestion of levodopa, which is decarboxylated endogenously to dopamine, produces a sustained improvement in cardiac function. In the present study, levodopa was administered orally (1.5 to 2.0 g) to 14 patients with heart failure while hemodynamic responses and plasma catecholamines were monitored. Initially, an increase in cardiac index and stroke volume index was accompanied by a decline in systemic vascular resistance, mean pulmonary capillary wedge pressure and mean right atrial pressure. Heart rate and mean arterial pressure were unchanged. Plasma concentrations of dopamine rose substantially after drug ingestion and correlated significantly with changes in cardiac index (r = 0.73, p less than 0.05). After 12 weeks of treatment with levodopa, the changes in cardiac index, stroke volume index, systemic vascular resistance and plasma dopamine levels persisted (n = 12 patients). Moreover, a significant decrease occurred in the heart rate at rest. Although there was an initial tendency for plasma norepinephrine concentrations to increase, a return to control levels was documented after long-term treatment. Thus, tolerance to the hemodynamic actions of levodopa did not develop during long-term administration of the drug. The hemodynamic responses observed can be ascribed to the activation of beta 1-adrenoceptors and dopamine1 receptors by dopamine generated from levodopa. The dopamine2 activity of dopamine does not appear to be responsible for the improvement in cardiac performance produced by levodopa.
 ...
PMID:Sustained hemodynamic improvement during long-term therapy with levodopa in heart failure: role of plasma catecholamines. 368 Jul 99

Pindolol, a beta blocker with intrinsic sympathomimetic activity, was investigated in a randomised controlled trial of 100 patients presenting within 12 hours of uncomplicated acute myocardial infarction. Pindolol was given intravenously for 24 hours and orally for 48 hours to achieve serum levels above 10 ng/ml. Heart rate and arterial pressure, both systolic and diastolic, fell to a similar degree in actively treated and control patients. There was no significant difference between systolic blood pressure-heart rate product in actively treated and control patients during the first 72 hours of therapy. There was no increased incidence of cardiac failure, bradycardia, or AV conduction disturbance among pindolol-treated patients. Infarct size estimated from cumulative enzyme release did not differ significantly from controls regardless of whether pindolol was given within four hours or between four and 12 hours of symptom onset. However, fewer patients given pindolol within four hours required morphine. Use of pindolol during the acute phase of myocardial infarction did not appear to modify clinical course, hemodynamic determinants of myocardial oxygen demand, or enzymatically determined infarct size.
 ...
PMID:Failure of intravenous pindolol to reduce the hemodynamic determinants of myocardial oxygen demand or enzymatically determined infarct size in acute myocardial infarction. 391 79

A study of 203 patients with chronic heart block treated with oral long-acting isoprenaline showed that 85 (42%) were maintained satisfactorily on the drug for a mean period of 18.2 months. The survival rates at one, two, and three years were 76%, 64%, and 57% respectively. In 115 patients treatment by pacing became necessary to control symptoms, and in these patients the survival rates at one, two and three years were 83%, 72%, and 60%.The two most valuable guides to patients' response to oral isoprenaline are the response to a trial dose of intravenous isoprenaline and the type of dysrhythmia associated with their Adams-Stokes attacks. Patients with heart failure with slow ventricular rates and those with angina of effort do not respond to treatment with sympathomimetic drugs.The majority of patients with chronic heart block are elderly, and in view of the complexity of pacing systems, and the need for skilled supervision of paced patients, oral long-acting isoprenaline remains of value in the longterm management of chronic heart block, provided patients are carefully selected for this form of therapy.
 ...
PMID:Conservative treatment of chronic heart block. 576 91

Beta adrenergic blocking agents are effective antianginal agents and reduce the frequency of anginal attacks, nitroglycerin consumption, and improve exercise tolerance in patients with stable exertional angina pectoris. These drugs are effective in the management of exertional angina pectoris primarily due to their ability to block beta 1 receptors and thereby competitively blocking the effects of sympathetic stimulation (i.e. increase in myocardial oxygen demand) during exercise. In this report other pharmacological properties of these agents i.e. membrane stabilizing activity, intrinsic sympathomimetic activity and cardioselectivity are of little importance. Comparative studies with beta adrenergic blocking agents with different ancillary properties, utilizing intravenous preparations, acute single and multiple oral dosing and sustained oral therapy prescribed for several weeks or months, show that if used in equipotent doses all beta adrenergic blocking agents are equally effective antianginal agents. It should be recognized that therapy with these agents may precipitate heart failure or aggravate bronchospasm in susceptible patients. This can occur with cardioselective agents and with beta blockers which also have intrinsic sympathomimetic activity.
 ...
PMID:Beta adrenergic blocking agents for exertional angina pectoris. 612 93

The development of beta-adrenoreceptor-blocking drugs provided an important group of agents to treat the cardiovascular disorders hypertension, angina pectoris, and cardiac arrhythmias and to manage patients with thyrotoxicosis. For clinical purposes, these drugs can be divided into two groups, that is, those with intrinsic sympathomimetic activity (ISA) and those without (non-ISA). The non-ISA drugs include propranolol, which is noncardiac selective: labetalol, which is noncardiac selective with alpha blockade: and and metoprolol and atenolol, which are cardiac selective. The drugs with ISA include pindolol, oxprenolol, and alprenolol which are noncardiac selective, and practolol which is cardiac selective. These drugs resemble isoprenaline in chemical structure, but their interaction with the beta-adrenoreceptors causes no response or only a slight response if the drug has ISA. By occupying the receptors, they block excitation by noradrenaline released from the sympathetic nerves and by adrenaline from the adrenal medulla. Drugs with ISA appear to depress cardiac activity and to interfere with bronchodilator drive less than do non-ISA drugs. Beta-blocking drugs differ considerably in their bioavailability because of differences in the rate and extent of metabolism in the first past through the liver after absorption from the gut. The therapeutic dose range varies widely for those with low bioavailability but is more predictable for those with high bioavailability. The drugs also differ in plasma protein binding and in their receptor affinities. In addition to their usual adverse effects, which include exacerbation of cardiac failure, bronchospasm, sleep disturbances, and Raynaud's phenomenon, concern has arisen about possible ocular and mucocutaneous side effects with beta-blocking drugs. This is a recognized problem with practolol, and it is not certain whether it occurs with other beta-blocking drugs. A double-blind study reported here of 110 matched patients, 36 of whom were on pindolol for more than 2 years, did not reveal any evidence of oculomucocutaneous problems related to drug treatment.
 ...
PMID:Clinical pharmacology of adrenergic-adrenoreceptor-blocking drugs. 612 97

1 This study was designed to compare in a randomized cross-over trial pindolol, a beta-adrenoceptor blocking agent with intrinsic sympathomimetic activity and metoprolol, a cardioselective beta-adrenoceptor blocker lacking sympathomimetic activity in hypertensives with incipient heart failure. Cardiac function was investigated by M-Mode and 2D-echo-cardiography. 2 Both pindolol and metoprolol in equipotent doses lowered blood pressure to the same extent. 3 There was no difference in overall left ventricular function in ventricular geometry or in wall dynamics after either drug. 4 In comparison to metoprolol, pindolol produced less reduction in resting heart rate, cardiac index and ejection velocity reflecting the intrinsic sympathomimetic activity of the drug.
 ...
PMID:The influence of beta-adrenoceptor blockade on left ventricular function. 612 81

All available beta-adrenergic blocking agents share the property of blocking beta 1 adrenoceptors, including those in the heart. They differ, however, in their ability to block beta 2 receptors (cardioselectivity), their membrane stabilizing action, intrinsic sympathomimetic activity and their pharmacokinetic properties. The strongest evidence for efficacy in secondary prevention has been obtained with timolol, metoprolol and propranolol. Timolol and propranolol block all beta-receptor-mediated responses and are therefore nonselective, whereas metoprolol is relatively cardioselective. Propranolol and metoprolol have membrane stabilizing action, but timolol does not; none of these agents show intrinsic sympathomimetic activity. Thus, no ancillary property is a requirement for efficacy. All of these agents may precipitate heart failure, but this problem has been exaggerated, and transient failure during the early course of myocardial infarction is no longer a contraindication to therapy. Cardioselective agents cause less bronchospasm, but this can still occur, especially with higher dosages. In addition, these agents probably cause somewhat less fatigue and result in less hypertension during hypoglycemia than nonselective agents. The availability of at least three effective agents allows for a choice of therapy to offer individual patients.
 ...
PMID:Clinical pharmacology of the beta-blocking drugs: implications for the postinfarction patient. 613 42

Beta blockade is the cornerstone of the therapy for ischemic heart disease and is increasingly used as first-line therapy for hypertension. Three chief properties that distinguish among different beta blockers are cardioselectivity, intrinsic sympathomimetic activity (ISA) and pharmacokinetic differences. Cardioselectivity appears to confer some advantages, although there is a potential and serious danger in giving any beta blocker to patients with asthma, heart failure or active peripheral disease. The degree of ISA in different beta blockers may vary. This property may diminish the degree of cardiac depression caused by beta blockade, influencing the response to exercise, but on the other hand, it may make the beta blocker less beneficial in minimizing the effects of myocardial ischemia. Beta blockers also differ in duration of action, vasodilating capacity and effect on renal blood flow. Several mechanisms may be involved in the antihypertensive effects of beta antagonists. In elderly hypertensive patients, beta blockade should be given cautiously, especially if combined with a diuretic, and pharmacokinetic differences in this age group must be considered.
 ...
PMID:Basis for cardiovascular therapy with beta-blocking agents. 613 10

There is an increasing use and variety of beta-adrenoceptor blocking agents (beta-blockers) available for the treatment of hyperthyroidism. Recent comparative studies suggest that atenolol (200mg daily), metoprolol (200mg daily); acebutolol (400mg daily), oxprenolol ( 160mg daily), nadolol ( 80mg daily) and timolol (20mg daily) produce a beneficial clinical response equal to that seen with propranolol ( 160mg daily). Most beta-blockers reduce resting heart rate by approximately 25 to 30 beats/min, although a lesser reduction is seen with those possessing intrinsic sympathomimetic activity such as oxprenolol and pindolol. While earlier studies employing large doses of intravenous propranolol concluded that beta-blockade reduced myocardial contractility, more recent non-invasive studies suggest that the predominant cardiac effect is on heart rate. In patients with cardiac failure, beta-blockers may, however, produce a profound fall in cardiac output. Nevertheless, in combination with digoxin they may be useful in controlling the atrial fibrillation of thyrocardiac disease. beta-Blockers improve nervousness and tremor (although to a lesser extent with cardioselective agents) and severe myopathy, and they also reduce the frequency of paralysis in patients with thyrotoxic periodic paralysis. There is often subjective improvement in sweating but usually no major effect on eye signs. Recent studies show a 10% reduction in oxygen consumption/basal metabolic rate with long term oral use of selective or nonselective beta-blockers. In addition, many agents (propranolol, metoprolol, nadolol and sotalol but not acebutolol, atenolol or oxprenolol) reduce circulating tri-iodothyronine (T3) concentration by between 10 and 40%, although the clinical significance of this effect (if any) is not established. beta-Blockers may also have endocrinological effects on gastrin, cyclic AMP, catecholamines and other hormone levels. Given in adequate dosage, propranolol has been shown to control thyrotoxic hypercalcaemia. Minor side effects (nausea, headaches, tiredness, etc.) are quite common but overall beta-blockers are well tolerated by the thyrotoxic patient. The major use of these drugs is in symptomatic control while awaiting definitive diagnosis or treatment. As an adjunct to antithyroid drugs or radioactive iodine, beta-blockers will produce a satisfactory clinical response in the weeks to months before these forms of therapy produce a euthyroid state. beta-Blockers are more convenient than antithyroid drugs in the control of patients receiving therapeutic radioiodine, in that continuous therapy and assessment of biochemical response is possible.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Use of beta-adrenoceptor blocking drugs in hyperthyroidism. 614 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>