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Biomedical subjects

I Wallentin

Publications and source records attributed to I Wallentin.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effects of prenalterol administered orally in patients with congestive heart failure.

A single-blind study of prenalterol 20-200 mg daily in a slow-release tablet preparation and a placebo was performed in 15 patients with moderate to severe congestive heart failure (NYHA II-IV) to evaluate the haemodynamic and clinical effects of oral prenalterol. Non-invasive parameters in the measurement of cardiac output, stroke volume, pre-ejection period index (PEPI), PEP/LVET ratio, ejection fraction and mean Vcf were significantly improved, indicating beneficial effects of prenalterol on cardiac contractility. Systolic blood pressure, heart rate and rate-pressure product were slightly increased at rest but were considerably lower during exercise. Arrhythmogenecity was not seen in the patients studied. Subjective improvement was noted in the majority of patients as evidenced by a decreased frequency of dyspnoea, fatigue and angina. Unwanted effects, such as palpitations and transmitted arm pulsations, were transient and disappeared with dose adjustment, while the inotropic effect of the medication was maintained. The clinical response appeared to be sustained for up to 2 weeks of treatment, indicating non-development of tachyphylaxis.

Administration, Oral↗
PubMed1980

The diagnosis of atrial myxomas. Difficulties and pitfalls.

Altogether seven patients with the preoperative diagnosis of atrial myxoma were admitted to our hospital in 1968-78 and referred for surgery. In two patients no tumour was found at operation. In one of them the reason for the misinterpretation was severely malformed mitral leaflets. In the other the contrast medium was injected into a pulmonary vein, which caused a contrast defect due to inadequate mixing.

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↗
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↗
PubMed1977

Distortion of non-invasive cardiac pulse curves. A capillary-damped pick-up and a calibration unit forapex cardiograms and other pulse curves.

A calibration unit and a capillary-damped pick-up, of funnel type, intended for apex cardiograms and other non-invasive cardiac pulse curves are presented. The physical properties of a recording system, suitable for non-invasive cardiac diagnostic techniques, are reviewed. In 4 identical recording units consisting of a funnel with and without capillary damping, connected via air transmission to a transducer, the overamplification in the underdamped systems varied between 2-4 and 4-3, and in the capillary-damped systems between 1-1 and 1-2. The capillary damping gave an approximately linear relation between phase shift and frequency in the high frequency range with a calculated delay of about 4ms. The low frequency time constant in the systems varied between 1-9 and 4-6 s, depending on the amplifier setting used, which for sine curves of frequency 0-5 and 2 Hz means an apparent prematurity for their maxima and minima varying between 53 and 1 ms, this being larger with lower frequency time constants and lower frequency curves.

Amplifiers, Electronic↗
PubMed1977

Preliminary observations on interventricular septum vibrations: an echocardiographic sign in aortic valvular stenosis.

In previous experimental and clinical studies on aortic valvular stenosis it has been suggested that in addition to the degree of stenosis, other factors, such as the pathoanatomy of the valve and turbulence-induced vibrations, might be of importance. Using echocardiography, vibrations of the interventricular septum were demonstrated in six consecutive patients with congenital aortic stenosis. In comparable normal subjects no such vibrations could be seen. The clinical significance of ventricular wall vibrations has not yet been established.

Adolescent↗
PubMed1976

Sodium excretion and sympathetic activity in relation to severity of hypertensive disease.

The relationship between the severity of hypertensive disease and sodium excretion and sympathetic activity has been studied in subjects of the same age and sex derived from screening a total population. 19 untreated subjects with casual blood-pressure (B.P.) above 175/115 mm Hg on two separate occasions made up the hypertensive group. A normotensive group (n =19) was obtained by selecting a 5% random sample from all subjects with casual B.P. below 160/95. Sympathetic activity was determined from noradrenaline excretion and the severity of hypertension assessed by recording resting diastolic B.P., signs of left ventricular hypertrophy on orthogonal E.C.G., and the glomerular filtration-rate. In the hypertensive group the resting B.P. correlated well both with signs of left ventricular hypertrophy and with the glomerular filtration-rate--i.e., the degree of severity of the hypertension. Up to the level of 90 mm Hg resting diastolic B.P., sodium excretion rose in complete agreement with the theory of pressure diuresis. Above 90 mm Hg, however, sodium and noradrenaline excretion fell with increase of B.P. These two findings indicated that with increasing severity of hypertension the sodium balance overrides the sympathetic activity in the long-term regulation of B.P. This may have both prognostic and therapeutic implications.

Adrenal Medulla↗