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Biomedical subjects

R Sivertsson

Publications and source records attributed to R Sivertsson.

At least 55 records · Page 3Linked to original sources
PubMed1981

Possible relationship between psycho-emotional factors and haemodynamic patterns in the pathogenesis of mild blood pressure elevation.

1. Psycho-emotional profiles were compared with invasive haemodynamic findings in a population sample of 37 young men (mean age 27 years) with mild blood pressure elevation and in 21 matched normotensive controls. 2. In comparison with normotensive controls, subjects with hyperkinetic blood pressure elevation had higher irritability levels, more guilt feelings and more psychic distressful symptoms. 3. In subjects with blood pressure elevation and normokinetic circulation structural vascular changes were found, and their psycho-emotional profiles showed high irritability levels but not significantly increased guilt or anxiety. 4. These results indicate a relationship between psychological factors and haemodynamic patterns in mild blood pressure elevation. A psychosomatic aetiology in hyperkinetic blood pressure elevation is suggested, and the psychological findings are compatible with a gradual development from hyperkinetic to normokinetic blood pressure elevation.

Adult↗
PubMed1981

Haemodynamic effects of withdrawal of long-term treatment with beta-adrenoceptor blocking agents in subjects with essential hypertension.

1. After 10 years of beta-adrenoceptor blockade in five female patients with essential hypertension, the beta-adrenoceptor-blocking agent was withdrawn, and the women were then followed up for 1 year, with measurements of cardiac output and peripheral resistance. 2. Blood pressure remained low during the first year after withdrawal in spite of the fact that the heart rate increased within the first few days. 3. Cardiac output was found to increase during the first year after withdrawal, although total peripheral resistance was essentially unchanged. 4. The maintenance of low blood pressure after withdrawal of the antihypertensive drug might indicate a regression of structural changes in the resistance vessels during successful long-term antihypertensive treatment. 5. Minimal resistance in hands and calves did not increase during the year after withdrawal.

Adrenergic beta-Antagonists↗
PubMed1981

Metoprolol and pindolol in hypertension: different effects on peripheral haemodynamics.

1. Thirty-six patients with essential hypertension, were randomly allocated to double-blind treatment with either metoprolol (100--200 mg/day) or pindolol (5--10 mg/day). The effects upon blood pressure and peripheral blood flow were determined. Both drugs reduced blood pressure significantly. 2. Heart rate was significantly reduced by metoprolol but not by pindolol. 3. Vascular resistance at maximal dilatation was not changed by either pindolol. 4. At rest, pindolol reduced vascular resistance in the calf by 14% (P less than 0.05) but metoprolol tended to increase the resistance slightly. The difference in effect was also significant (P less than 0.005). 5. During leg muscle work there were no changes in vascular resistance in the forearm with either compound. 6. We conclude that pindolol appears to reduce blood pressure at least partly through vascular mechanisms, in contrast to metoprolol. The response to sympathetic stimulation induced by physical exercise does not differ between metoprolol- and pindolol-treated patients.

Double-Blind Method↗
PubMed1981

Blood flow resistance in the hand after coarctectomy.

Patients with established hypertension have an increased blood-flow resistance at maximal vasodilatation, which has been interpreted as being caused by a wall thickening in the resistance vessels. Hand blood-flow resistance at maximal vasodilatation was estimated from intra-arterial mean blood pressure and plethysmographically determined hand blood-flow in ten young men, operated upon for coarctation of the aorta during childhood. The patients were compared with different reference groups examined in the same way. The resting mean blood pressure in the coarctation group was only slightly elevated, to the level of a group of patients with mild blood pressure elevation, while the blood-flow resistance at maximal vasodilatation was markedly increased and equalled that found in a group of patients with established hypertension. This discrepancy between blood pressure and blood-flow resistance suggests a limited reversibility of structural changes in the resistance vessels, originating from the preoperative period with high blood pressure, and might be an argument in favour of early operation and/or antihypertensive medication in children with coarctation of the aorta.

Adolescent↗
PubMed1981

Baroreceptor reflexes after coarctectomy.

Patients with hypertension have a impaired baroreflex sensitivity, the reduction being proportional to the blood pressure elevation. Coarctation of the aorta is characterized by hypertension in the upper part of the body. In eight young men, operated upon for coarctation of the aorta during childhood, baroreflex sensitivity was estimated from the prolongation of the R-R interval during the transient rise of arterial blood pressure induced by intravenous injections of small doses of angiotensin. The patients were compared with normotensive and hypertensive reference groups, of the same age and sex, who were examined in the same way. The resting mean blood pressure in the coarctation group was slightly elevated, and the baroreflex sensitivity was reduced proportionally. The fact that the baroreceptors were more sensitive than would be expected from the patients pre-operative high blood pressure suggests that the baroreceptor-resetting in high blood pressure is to a considerable degree reversible when the blood pressure is reduced.

Adolescent↗
PubMed1981

Blood pressure and heart rate recordings at home and at the clinic. Evidence for increased cardiovascular reactivity in young men with mild blood pressure elevation.

In 41 apparently healthy men, aged 22-25 years, with mild blood pressure elevation (MBPE) and 19 age- and sex-matched normotensive controls (MC), blood pressure (BP) and heart rate (HR) readings at the clinic were compared to self-determined morning and afternoon values at home. The criteria for inclusion in the MBPE group were auscultatory BP less than 150 mmHg systolic and/or less than 90 mmHg diastolic at the military enlistment center from which the subjects were recruited, and systolic BP less than 140 mmHg on two subsequent occasions at the clinic. The BPs of the controls, who were mainly recruited from the same center, did not exceed 130/80 mmHg either at the enlistment center or at the clinic. The magnitude of the difference in systolic BP between home and clinic readings in the MBPE group (+15.3 mmHg) differed significantly from that in the NC group (+1.8 mmHg) (p less than 0.001). In both groups the systolic BP increased slightly but significantly during the day and was higher at home in the afternoon than in the morning. HR showed the same type of variation as BP in both groups with higher values at the clinic. The rise tended to be more pronounced (p less than 0.1) in patients with MBPE. Surprisingly, resting HR at home in the morning was significantly lower in the MBPE than in the NC group. Normokinetic and hyperkinetic subgroups of patients with MBPE did not differ from each other with respect to the variations in HR and BP studied.

Adult↗
PubMed1981

Hypertension in the elderly. Hypertension seminars at Ostra Hospital, Göteborg, Sweden.

A review on the effects of ageing on cardiovascular function, with special reference to high blood pressure (BP), is given in this seminar. In most western populations the diastolic and especially the systolic BP increases with age in both sexes and this has been observed both in cross-sectional and longitudinal studies. Over the age of 60 the diastolic BP decreases. Of the different risk factors for cardiovascular diseases, only BP has been shown consistently to be an independent risk indicator in subjects 70 years or older. Hypotensive drugs used in the treatment of middle-aged hypertensive patients can also reduce the BP in elderly hypertensive patients can also reduce the BP in elderly hypertensive patients but are likely to produce more adverse reactions such as electrolyte disturbances and glucose intolerance by thiazides, depression by reserpine, orthostatic hypotension by methyldopa and excessive bradycardia by beta-blockers. A prolongation of life expectancy in hypertensive patients 60 years or older by hypotensive drug therapy has not been shown conclusively in controlled trials.

Adult↗
PubMed1980

Borderline hypertension. Hypertension seminars at Ostra Hospital, Göteberg, Sweden.

Borderline hypertension was the topic of one of the "Hypertension seminars" arranged by the Hypertension Section at the Ostra Hospital, Göteborg, Sweden. On that occasion Professor Stevo Julius, Ann Arbor, Michigan USA, was an invited guest. During the seminar, various aspects of borderline hypertension were discussed, e.g. the natural history, hemodynamics and management of this condition. The present review is based on these discussions.

Adolescent↗
PubMed1979

Blood pressure reduction and vascular adaptation. A study on long-term effects of treatment with mefruside or atenolol.

Systemic BP reduction, calf blood flow and vascular resistance in the calf were determined in forty-two previously untreated patients with mild to moderate essential hypertension (WHO I-WHO II) before and after 6 weeks, 6 months and 18 months of BP-lowering treatment with mefruside (25 mg daily) or atenolol (100--400 mg daily). Blood flow was determined with venous occlusion plethysmography using a mercury-in-rubber strain gauge technique in the supine patient. Auscultatory BP was measured on the right arm simultaneously with the flow determinations and resistance was calculated from the flow and pressure. BP was reduced significantly and to the same extent by the two drugs. In the atenolol group a rise in resting resistance and a corresponding fall in resting blood flow was seen initially. These changes were entirely normalized during continued treatment for 18 months. In the mefruside group no significant haemodynamic changes during treatment were observed at rest apart from the BP fall. None of the drugs reduced resistance at "maximal" vasodilatation, indicating that no regress of the hypertensive structural changes of the calf blood vessels had taken place.

Adult↗
PubMed1978

Coronary heart-disease after treatment of hypertension.

Within a group of 1026 men aged 47-54, cause-specific death-rates and the incidence of non-fatal myocardial infarction and stroke in treatment group of 635 hypertensive men (casual systolic B.P. greater than 175 or diastolic B.P. greater than 115 mm Hg on two occasions) treated at a hypertension clinic were compared with those in a control group of 391 men (causal systolic B.P. greater than 175 or diastolic greater than 115 mm Hg on only one occasion) who remained mainly untreated during their 4.3 years of follow-up. The predicted risk of coronary heart-disease (C.H.D.) at entry, calculated by a multiple logistic function, was slightly higher in the treatment group. Total death-rate during follow-up was significantly lower in the treatment group (3.3%) than in the control group (6.1%). The difference in death-rate for C.H.D. was of the same relative order (0.8% versus 1.5%), as was the incidence of non-fatal myocardial infarction (2.8% versus 5.4%), although none of the differences reached statistical significance. However, the pooled incidence of fatal and non-fatal C.H.D. was significantly lower in the treatment group (3.6%) than in the control group (6.9%). The results suggest that antihypertensive treatment might be effective in preventing or postponing C.H.D. in middle-aged men.

Cerebrovascular Disorders↗
PubMed1978

Inhibitory effects of vibrations on contractility of isolated rabbit papillary muscle.

The effects of vibrations on myocardial contractility have been tested in isolated rabbit papillary muscles. Sinusoidal longitudinal oscillations were found to inhibit active force in the paced preparation to an extent which depended on vibration amplitude and frequency. The inhibitory effect of vibrations on myocardial contraction resembled that previously seen in other types of muscle. Vibration during the inactive phase did not alter passive muscle tension. When the vibrator was controlled by phonocardiographic recordings from a normal subject or from patients with congenital aortic stenosis, pronounced inhibition was obtained only by vibrations corresponding to a systolic murmur. It is concluded that the myocardium is sensitive to oscillating length changes. If the ventricular muscle in vivo is exposed to vibrations during systole the cardiac function might be seriously interfered with.

Animals↗