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Biomedical subjects

A Hjalmarson

Publications and source records attributed to A Hjalmarson.

At least 289 records · Page 16Linked to original sources
PubMed1982

Beta-receptor blocker withdrawal. A preoperative problem in general surgery?

A prospective randomized study was performed in 91 patients scheduled for general surgery on 99 occasions. The patients were chronically (greater than 3 months) treated with beta-receptor blockers because of ischaemic heart disease and/or hypertension and the beta-receptor blockade was either gradually withdrawn (n = 51) during 4 days preoperatively or continued until surgery (n = 48). The effects on arterial blood pressure (BP), heart rate (HR) and rate-pressure product (RPP) at rest and the incidence of chest pain during daily activities were registered. A withdrawal of the beta-receptor blockade was associated with increases of HR (in eight patients greater than 30 beats min-1) and RPP and in patients treated for hypertension there were also increases of systolic and diastolic BP (in five patients greater than or equal to 30/15 mmHg). Patients who continued the beta-receptor blockade until surgery showed no changes. Nine out of 23 patients with a previous history of ischaemic heart disease had an increase of chest pain after withdrawal of the beta-receptor blockers, whereas none of the corresponding 25 patients who continued the therapy suffered from an increased chest pain. Due to the severity of symptoms after beta-receptor blocker withdrawal, surgery had to be postponed in 4 patients. The observations suggest that a 4-day preoperative withdrawal of long-term beta-receptor blockade is potentially hazardous in ischaemic and/or hypertensive patients.

Adrenergic beta-Antagonists↗
PubMed1982

Beta-receptor blockade and spinal anaesthesia. Withdrawal versus continuation of long-term therapy.

A prospective study was performed in 43 men scheduled for transurethral resections under spinal anaesthesia. All patients were on chronic beta-receptor blockade because of hypertension and/or ischaemic heart disease. The patients were randomly subjected to either a gradual preoperative withdrawal or a continuation of the beta-receptor blockade. Haemodynamics were measured non-invasively. Spinal anaesthesia was performed and an i.v. injection of atropine given. The patients were then placed in a lithotomy position. Mean anaesthetic level included T6. After beta-receptor blocker withdrawal consistently elevated heart rates, a high incidence of arhythmias, angina pectoris and postoperative ST-T changes indicating myocardial ischaemia were seen. These changes were not seen in patients with continued beta-receptor blockade. Withdrawal of beta-receptor blockers was also associated with an increased total peripheral vascular resistance in connection with spinal anaesthesia. These results suggest that patients on long-term beta-receptor blockade should continue the therapy during and after spinal anaesthesia.

Adrenergic beta-Antagonists↗
PubMed1981

Effect on mortality of metoprolol in acute myocardial infarction. A double-blind randomised trial.

The effect of metoprolol on mortality was compared with that of placebo in a double blind randomised trial in patients with definite or suspected acute myocardial infarction. Treatment with metoprolol or placebo started as soon as possible after the patient's arrival in hospital and was continued for 90 days. Metoprolol was given as a 15 mg intravenous dose followed by oral administration of 100 mg twice daily. 1395 patients (697 on placebo and 698 on metoprolol) were included in the trial. Definite acute myocardial infarction developed in 809 and probable infarction in 162. Patients were allocated to various risk groups and within each group patients were randomly assigned to treatment with metoprolol or placebo. There were 62 deaths in the placebo group (8.9%) and 40 deaths in the metoprolol group (5.7%), a reduction of 36% (p less than 0.03). Mortality rates are given according to the treatment group to which the patients were initially randomly allocated.

Adult↗
PubMed1981

Clinical results with prenalterol in patients with heart failure.

The hemodynamic effect of 75 to 225 microgram/kg prenalterol (PNL) intravenously were studied at rest and during exercise in eight patients with chronic congestive heart failure (CHF) after myocardial infraction (three patients), valvular surgery (three patients), and congestive cardiomyopathy (two patients). All head New York Health Association functional class III and IV CHF and were receiving digitalis and diuretics. With PNL at rest, left ventricular filling pressure (LVFP) fell from 17 to 12 mm Hg, cardiac index (CI) rose from 2.1 to 2.9 L/min/m2, heart rate (HR) increased mildly, systemic vascular resistance (SVR) declined moderately, and peripheral arterial pressure was unchanged. During PNL exercise compared with control, LVFP rise was less and CI, HR, and SVR responses were similar; dyspnea and angina were reduced in most patients. The eight patients were than given PNL orally, 30 to 200 mg/day, versus placebo for 6 days with comparative evaluation by echocardiogram, systolic time intervals (STI), exercise test, and continuous ECG. With PNL orally five of eight patients improved symptomatically, ejection fraction increased from 0.44 to 0.53, and STI preejection period shortened by 10 msec, without change in resting HR or systemic arterial blood pressure. The incidence of ventricular premature beats was not increased. PNL orally vs placebo exercise capacity increased 10%. Thus PNL may be of value for long-term CHF treatment in addition to conventional therapy.

Administration, Oral↗
PubMed1981

Acute intervention with metoprolol in myocardial infarction.

Studies in experimental and clinical myocardial infarction support the idea that sympathetic activity and myocardial noradrenaline release play a significant role in the development of myocardial ischemic damage. Betablockade has been shown to limit infarct size and lower the incidence of ventricular fibrillation in experimental models. Betablockade to patients (pts) with acute myocardial infarction (AMI) has been shown to reduce ischemia reflected as reduction of ischemic chest pain, decrease ST-segment elevation and increase lactate extraction. Whether this treatment in the clinical situation can prevent development of infarction, reduce infarct size and early mortality in man remains to be proven. In Gøteborg a double-blind study on metoprolol and placebo was started four and a half years ago. Inclusion of pts. in the study has been terminated and survival data will be available on May 1, 1981. 1395 pts. were included of whom 800 developed AMI. Metoprolol 15 mg was given IV followed by a total daily dose of 200 mg/day. The tolerance for betablockade was generally good. Analysis of serum enzyme estimations of maximal LD I + II showed a significant reduction by metoprolol when the treatment was given within 12 hours of onset of pain. In a subgroup consisting of 103 pts. with AMI metoprolol had no clearcut effects on the ventricular arrhythmias during the first 24 hours in hospital. The betablockade resulted in a 15% reduction in heart rate. The main objective of this study, the mortality during three months of blind treatment will be published late in 1981.

Adult↗
PubMed1980

Beneficial effects of long-term beta-blockade in congestive cardiomyopathy.

Twenty-eight patients with heart failure caused by congestive cardiomyopathy, which had been diagnosed according to the criteria of Goodwin and Oakley, were treated with beta-blocking agents for six to 62 months, except for four patients who died within two months. Repeated non-invasive investigations were performed before and during treatment as well as exercise tests and chest x-rays. The echocardiographic and pulse curve findings indicated an improvement in systolic and diastolic myocardial function. The ejection fraction increased from 0.32 +/- 0.02 to 0.42 +/- 0.04, and the third heart sound amplitude and rapid filling wave were significantly reduced. The functional classification improved in 15 patients while in 12 patients it remained unchanged and in one it deteriorated. During follow-up, 10 patients died, most of them suddenly. The mortality was lower than expected in this severely ill group of patients. The beneficial effect of chronic beta-blockade in patients with congestive cardiomyopathy suggests that catecholamines are involved in the pathogenesis of congestive cardiomyopathy, and that patients with congestive cardiomyopathy may have inappropriate sympathetic cardiac stimulation which can be reduced by chronic beta-blockade. It is suggested that beta-receptor blockade should be added to conventional treatment with digitalis and diuretics in all patients with severe myocardial failure caused by congestive cardiomyopathy.

Adolescent↗
PubMed1980

Adverse effects of beta-blockade withdrawal in patients with congestive cardiomyopathy.

Fifteen patients with congestive cardiomyopathy who had improved conspicuously on chronic administration of a beta-blocker were studied after withdrawal of the drug. In six patients there was a pronounced deterioration of their clinical condition, and in all of the remaining patients there was a significant decrease in ejection fraction, and signs of compromised diastolic function with pathological apex curves and an increase in third heart sound. All these changes were reversed within a few weeks to a few months after readministration of beta-blocking drugs. This study supports the idea that an aetiological factor in congestive cardiomyopathy may be a pathological response to sympathetic stimulation which could be partly controlled by administration of beta-blocking drugs.

Adolescent↗
PubMed1980

Myocardial metabolic changes related to ventricular fibrillation.

The cause of death in patients who die suddenly or after an acute myocardial infarction is, in most cases, ventricular fibrillation. Most of these patients suffer from ischemic heart disease and atherosclerotic narrowing of the coronary arteries. Ischemic changes include hypoxia, accumulation of metabolites, depletion of energy-yielding substrates, ionic shifts and structural changes. There is an increased sympathetic activity and often a higher vagal tone. Recent observations support the idea that there is an elevated regional adrenergic activity in the ischemic area with increased tissue levels of cyclic AMP. This seems to be one of several important factors contributing to the occurrence of ventricular fibrillation. Increased sympathetic activity might mediate reentry mechanisms as well as enhanced automaticity.

Arrhythmias, Cardiac↗
PubMed1979

Prolongation of survival in congestive cardiomyopathy by beta-receptor blockade.

24 patients with congestive cardiomyopathy (group I) were compared with a group of 13 controls with similar clinical findings and myocardial function who were selected retrospectively (group II) . All patients received digitalis and diuretics, but group I patients received beta-blockers as well. The survival-rate in group I patients (83%, 66%, and 52% after one, two, and three years respectively) differed significantly from that in group II subjects (46%, 19%, and 10%, respectively). This finding is supported by the demonstration that beta-blockade improved myocardial function in group I subjects. It is therefore suggested that beta-blockade prolongs survival in patients with congestive cardiomyopathy.

Adolescent↗
PubMed1979

Effects of work and acute beta-receptor blockade on myocardial noradrenaline release in congestive cardiomyopathy.

Systemic hemodynamic changes and noradrenaline concentrations in coronary sinus blood were studied at rest and during work before and after acute beta-receptor blockade. Patients with congestive cardiomyopathy were compared to patients with primary valvular diseases and to healthy subjects. Noradrenaline concentrations were higher in coronary sinus blood than in arterial blood and increased after beta blockade and during work. Noradrenaline concentrations were more increased in patients with more pronounced myocardial failure and did not seem to separate patients with congestive cardiomyopathy from those with valvular disease. Patients with congestive cardiomyopathy showed a good hemodynamic tolerance toward acute beta blockade.

Adolescent↗
PubMed1979

Haemodynamic effects of a new beta 1-receptor agonist in acute myocardial infarction. A useful antidote to unwanted cardiac effects of beta-blocking agents.

The haemodynamic effects of a new beta 1-receptor agonist, 1-(4 hydroxyphenoxy) 3-isopropylamino-2-propanol, were studied in 25 patients after acute myocardial infarction using non-invasive methods. The drug caused an increase in systolic blood pressure and pulse pressure, without change in diastolic blood pressure, and a slight increase in heart rate and reduction in the pre-ejection period. These changes were greater in patients without a history of left heart failure. It is suggested that this cardioselective drug possesses positive inotropic activity but only slight positive chronotropic activity. The substance has been further investigated as a possible antidote to unwanted cardiac side effects of the cardioselective beta-blocker, metoprolol. The changes in the cardiovascular dynamics caused by metoprolol in patients with acute myocardial infarction were promptly reversed by this new beta 1-agonist. With its positive inotropic properties and its efficacy in reversing the effects of a cardioselective beta-blocker, the drug is a potentially useful pharmacological agent to support an acutely depressed myocardium in patients on beta-blocking agents.

Acute Disease↗