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Biomedical subjects

L Hulthén

Publications and source records attributed to L Hulthén.

13 recordsLinked to original sources
PubMed1991

Long-term results after percutaneous transluminal angioplasty of atherosclerotic renal artery stenosis--the importance of intensive follow-up.

The aim of this study was to investigate the long-term results of percutaneous transluminal angioplasty of atherosclerotic renal artery stenosis (PTRA) in patients with renovascular hypertension with or without impending renal insufficiency who were followed up intensively with aggressive reintervention. Diagnostic work-up was based on angiography, pressure gradient and renal venous renin measurement. Patients were scheduled for regular follow-up after the PTRA and a deterioration in blood pressure or renal function was an indication for re-evaluation, and reintervention if necessary. Sixty-five patients had 71 renal artery stenoses where PTRA was attempted. It was technically successful in 59 stenoses and two occlusions and failed in ten (14%). At the end of follow-up (median 56 months [2-99]), the primary patency rate was 55%, 27 had restenosed and four were occluded, all but two within 12 months. Seventeen were treated by a further PTRA and eight by surgical reconstruction. At the end of follow-up the secondary patency after all interventions was 90%. One patient died 1 month after PTRA, and at the end of follow-up 21 patients (32%) had died, most of them (80%) from cardiovascular disease. Multivariate analyses showed a significantly reduced survival rate in patients with multiocular atherosclerosis, renal insufficiency, contralateral renal artery stenosis and ischaemic heart disease. At the end of follow-up 90% of the patients were cured or improved with regard to blood pressure. In patients with impending renal insufficiency renal function was improved in 50% and unchanged in 39%. With this strategy 55% of the patients needed only one treatment with PTRA, 25% needed a re-PTRA and 20% had to be operated on. PTRA can be recommended as initial treatment of atherosclerotic renal artery stenosis provided intensive follow-up and aggressive reintervention are performed when indicated.

Adult↗
PubMed1990

Antihypertensive and renal effects of enalapril and slow-release verapamil in essential hypertension. A double-blind, randomized study.

The renal, metabolic and antihypertensive effects of enalapril (E) and slow-release verapamil (V) were compared in a 2-month double-blind crossover trial in 22 patients with newly discovered essential hypertension. The glomerular filtration rate and renal vascular resistance were unaltered: renal blood flow was slightly decreased by V. Serum Ca2+ increased and Na+ excretion declined after V. Serum lipids, glucose, and erythrocyte electrolytes were unchanged. Blood pressure (BP) was lower with E after half the maximum dosage compared with V, but similar BP reductions were obtained after 2 months with the maximum dosage.

Adult↗
PubMed1986

Hemodynamic effects of calcium channel blockers in essential hypertension.

Calcium channel blockers decrease blood pressure in essential hypertension due to a marked reduction of systemic vascular resistance (arteriolar tone). They also dilate conducting arteries but have no venodilatory effect in antihypertensive doses. With the dihydropyridines (e.g. nifedipine) and diltiazem there is a transient increase in heart rate and cardiac output but this is not observed with verapamil. The vasodilatory responsiveness in the resistance vessels to calcium channel blockers is selectively enhanced in patients with established essential hypertension but not in the early borderline phase of hypertension. During treatment with chlorthalidone, atenolol, acebutolol or nitrendipine for four to six weeks the reduction of blood pressure is accompanied by a selective decrease in the vasodilatory responsiveness to calcium channel blockers.

Blood Pressure↗
PubMed1983

Verapamil-induced vasodilator response is enhanced in essential hypertension.

Forearm blood flow response to the calcium channel inhibitor verapamil, 1 75 micrograms/100 ml tissue, as measured by venous occlusion plethysmography, was found to be significantly greater in 11 patients with essential hypertension as compared to 11 age-matched normotensive subjects whereas there was no significant difference in increase in forearm blood flow between both groups to non-specific vasodilatation with sodium nitroprusside (1.2 micrograms/100 ml tissue). The increase in forearm blood flow to verapamil correlated positively with basal plasma epinephrine concentration in hypertensives. These findings support the concept of an increased dependency of arteriolar tone on calcium influx in patients with essential hypertension, an abnormally related to the activity of the sympathetic nervous system.

Adult↗
PubMed1982

Elevated adrenaline and increased alpha-adrenoceptor-mediated vasoconstriction in essential hypertension.

In patients with essential hypertension, plasma adrenaline, regardless of age, was consistently higher than in normotensive controls; adrenaline correlated with heart rate and the vasodilator response in the forearm circulation produced by postjunctional alpha 1-adrenoceptor blockade with prazosin. This dilator response to prazosin was greater in hypertensive patients. Together, this suggests elevated sympathetic activity and enforced vasoconstriction via postjunctional alpha 1-adrenoceptors in essential hypertension. beta-Adrenoceptor-mediated cardiovascular responses decrease with age and even more with high blood pressure, which contributes to unopposed alpha-adrenoceptor-mediated vasoconstriction. This could explain the transition from an early high cardiac output into a later high peripheral resistance form of hypertension.

Adaptation, Physiological↗
PubMed1978

The effect of the converting enzyme inhibitor SQ 20.881 on kinins, renin-angiotensin-aldosterone and catecholamines in relation to blood pressure in hypertensive patients.

Nine sodium replete hypertensive patients with normal or high plasma renin activity (PRA) were given SQ 20.881, 1 mg/kg intravenously BP fell significantly within 20 min and reached its lowest level after 60 min. Blood kinins showed a minor but significant decrease after 60 and 105 min. Plasma angiotensin II was markedly reduced after 15 and 60 min. PRA was significantly increased after 15-105 min. Plasma aldosterone was reduced at 60 min in eight patients and slightly increased in one. Plasma noradrenaline increased after 15 min, whereas adrenaline decreased after 60 min. These results indicate that the reduction of BP following inhibition of converting enzyme by SQ 20.881, 1 mg/kg, is not related to reduced degradation of kinins but rather to decreased formation of angiotensin II. Angiotensin II appears to be of importance for the maintenance of BP in sodium replete hypertensive patients with normal or high PRA.

Adult↗