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T Lüscher

Publications and source records attributed to T Lüscher.

At least 19 recordsLinked to original sources
PubMed2001

The relevance of tissue angiotensin-converting enzyme: manifestations in mechanistic and endpoint data.

Angiotensin-converting enzyme (ACE) is primarily localized (>90%) in various tissues and organs, most notably on the endothelium but also within parenchyma and inflammatory cells. Tissue ACE is now recognized as a key factor in cardiovascular and renal diseases. Endothelial dysfunction, in response to a number of risk factors or injury such as hypertension, diabetes mellitus, hypercholesteremia, and cigarette smoking, disrupts the balance of vasodilation and vasoconstriction, vascular smooth muscle cell growth, the inflammatory and oxidative state of the vessel wall, and is associated with activation of tissue ACE. Pathologic activation of local ACE can have deleterious effects on the heart, vasculature, and the kidneys. The imbalance resulting from increased local formation of angiotensin II and increased bradykinin degradation favors cardiovascular disease. Indeed, ACE inhibitors effectively reduce high blood pressure and exert cardio- and renoprotective actions. Recent evidence suggests that a principal target of ACE inhibitor action is at the tissue sites. Pharmacokinetic properties of various ACE inhibitors indicate that there are differences in their binding characteristics for tissue ACE. Clinical studies comparing the effects of antihypertensives (especially ACE inhibitors) on endothelial function suggest differences. More comparative experimental and clinical studies should address the significance of these drug differences and their impact on clinical events.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

[Cardiovascular disease in pregnancy].

There is a heterogeneous population of young women with cardiovascular disease contemplating pregnancy. Many of the conditions are rare and require teams with expertise in the management of such patients. A specific congenital or acquired cardiovascular anomaly and its physiology must be understood. The nature of prior surgical procedures and the residua and sequelae following therapy are essential to manage a pregnant woman with cardiovascular disease. Physiologic changes during pregnancy and after delivery must be known. Counseling includes maternal and fetal risk stratification and genetic counseling regarding inherited disorders. The outcome of pregnancy is favourable in many women with good functional class. These patients can be reassured. A multidisciplinary approach may be crucial to manage this population during pregnancy, labour, delivery and in the postpartum period to avoid serious maternal and fetal complications. Women with intermediate and high risk pregnancy must be followed and managed in a high risk pregnancy unit and a team from obstetricians, cardiologists, anesthetists, pediatricians, neonatologists and cardiac surgeons who are skilled in high risk pregnancies. Vaginal delivery is the method of choice in many women (class 1 woman) and cesarean section is seldom a cardiac indication. Contraindications for pregnancy are: poor maternal functional class, poor ventricular function, severe cyanosis without pulmonary hypertension (oxygen saturation < or = 85%), pulmonary vascular disease, severe mitral stenosis, severe left ventricular outflow tract obstruction, Marfan syndrome with aortic dilatation (> 40 mm) and aortic valve involvement (moderate to severe aortic regurgitation), symptomatic hypertrophic obstructive cardiomyopathy. Preconception counseling must be offered if unfavourable outcome is likely. Tubal ligation is probably the safest and most appropriate method of sterilization if there is a high risk pregnancy.

Adult↗
PubMed1998

Nitrate induced coronary vasodilatation: differential effects of sublingual application by capsule or spray.

BACKGROUND: Sublingual nitroglycerin (glyceryltrinitrate, GTN) capsules or isosorbide dinitrate (ISDN) spray are routinely used to treat anginal attacks and to vasodilate maximally the epicardial coronary arteries during coronary angiography. OBJECTIVE: To compare the coronary vasodilatory effects of GTN capsules and ISDN spray with those induced by intracoronary GTN using quantitative coronary angiography. DESIGN: 96 patients (79 men and 17 women; median age 59 years) were randomised to four groups to receive either a sublingual capsule containing 0.8 mg GTN or two puffs of spray delivering 0.8 mg ISDN, followed or preceded by an intracoronary bolus of 0.2 mg GTN used as reference for maximal vasodilatation. RESULTS: There was a significant increase in the mean diameter of coronary arteries in angiographically normal segments in patients who received either intracoronary GTN (groups 1 and 2) or ISDN spray (group 4) as a first application (group 1, 0.46 mm, + 17%, (baseline vessel diameter 100%), p < 0.001; group 2, 0.45 mm, + 13%, p < 0.001; group 4, 0.47 mm, + 13%, p < 0.05). Patients who received a sublingual GTN capsule as the first application mode (group 3) had no significant change in epicardial vessel diameter (0.10 mm, + 5%, p = 0.3). CONCLUSIONS: Sublingual ISDN spray may be more efficacious than sublingual GTN capsules in certain patients with anginal attacks. ISDN spray should be preferred over capsules in coronary angiographic procedures.

Acute Disease↗
PubMed1997

Tetrahydrobiopterin restores endothelial function in hypercholesterolemia.

In hypercholesterolemia, impaired nitric oxide activity has been associated with increased nitric oxide degradation by oxygen radicals. Deficiency of tetrahydrobiopterin, an essential cofactor of nitric oxide synthase, causes both impaired nitric oxide activity and increased oxygen radical formation. In this study we tested whether tetrahydrobiopterin deficiency contributes to the decreased nitric oxide activity observed in hypercholesterolemic patients. Therefore, L-mono-methyl-arginine to inhibit basal nitric oxide activity, serotonin to stimulate nitric oxide activity, and nitroprusside as endothelium-independent vasodilator were infused in the brachial artery of 13 patients with familial hypercholesterolemia and 13 matched controls. The infusions were repeated during coinfusion of L-arginine (200 microg/kg/min), tetrahydrobiopterin (500 microg/min), or the combination of both compounds. Forearm vasomotion was assessed using forearm venous occlusion plethysmography and expressed as ratio of blood flow between measurement and control arm (M/C ratio). Tetrahydrobiopterin infusion alone did not alter M/C ratio. Both the attenuated L-mono-methyl-arginine-induced vasoconstriction as well as the impaired serotonin-induced vasodilation were restored in patients during tetrahydrobiopterin infusion. Tetrahydrobiopterin had no effect in controls. In conclusion, this study demonstrates restoration of endothelial dysfunction by tetrahydrobiopterin suppletion in hypercholesterolemic patients.

Adult↗
PubMed1995

Endothelin-1 plasma levels in normal-tension glaucoma: abnormal response to postural changes.

BACKGROUND: Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelial cells. ET-1 may have a role in the pathogenesis of various vascular diseases. There are reports in the literature that ET-1 plasma levels are raised in normal-tension glaucoma (NTG) patients. METHODS: ET-1 concentration, plasma renin activity, and 24-h blood pressure were measured in 21 high-tension glaucoma (HTG) patients, 19 NTG patients, and 20 non-glaucomatous controls in supine and upright positions. RESULTS: ET-1 plasma levels tended to be higher in NTG patients (3.2 +/- 2.2 pg/ml) than in HTG patients (2.2 +/- 0.6 pg/ml) and controls (2.6 +/- 0.7 pg/ml). The differences, however, were not statistically significant. The individual scatter was significantly greater in the NTG group, indicating that our NTG patients are a heterogeneous population. The physiological increase in ET-1 plasma level after changing from the supine to the upright position was absent in NTG patients. Plasma renin activities tended to be lower in NTG patients (1.2 +/- 1.2 ng/ml/h) than in HTG patients (1.3 +/- 0.8 ng/ml/h) and controls (2.0 +/- 1.7 ng/ml/h). This may explain why NTG patients had relatively low blood pressure despite high ET-1 levels. CONCLUSIONS: Our data support the hypothesis that vascular dysfunction may be involved in the pathogenesis of optic nerve damage in normal-tension glaucoma.

Blood Pressure↗
PubMed1993

Endothelium-derived contracting factors in resistance arteries of young spontaneously hypertensive rats before development of overt hypertension.

Vascular relaxations are impaired in adult spontaneously hypertensive rats (SHRs) because of increased production of an endothelium-derived, cyclooxygenase-dependent contractile factor or factors. To test the hypothesis that alterations in endothelial function precede and contribute to the development of overt hypertension in SHRs, we compared in myographs endothelium-mediated relaxations of mesenteric resistance arteries from 4-week-old SHRs and Wistar-Kyoto (WKY) rats. Acetylcholine (10(-9) to 10(-4) M) induced comparable relaxations in SHR and WKY arteries precontracted (ED50) with norepinephrine. In arteries obtained from SHRs but not from WKY rats, relaxations were replaced by contractile responses with higher concentrations of acetylcholine (10(-6) to 10(-5) M). The contractile responses were endothelium dependent, were augmented by nitro L-arginine (10(-4) M), and were prevented by pretreatment with indomethacin (10(-5) M) or 3-amino-1,2,4-triazole (10(-3) M), an inhibitor of superoxide anion production via the cyclooxygenase pathway. Inhibition of thromboxane synthetase (CGS-13080, 5 x 10(-5) M) and antagonism of prostaglandin H2/thromboxane A2 receptors (SQ-29,548, 5 x 10(-5) M) failed to block the contractile response to acetylcholine in SHR arteries. Acetylcholine-mediated relaxations were significantly impaired in mesenteric arteries from 16-week-old SHRs but not from WKY rats. Endothelium-independent relaxations produced by sodium nitroprusside and contractile responses to norepinephrine and endothelin were comparable in arteries from SHRs and WKY rats of all ages. In summary, endothelium-dependent relaxations of mesenteric arteries from "prehypertensive" SHR rats were impaired by the production of a contractile factor (or factors) that appears to be superoxide anions.

Age Factors↗
PubMed1993

Progression of aortic stenosis. Role of age and concomitant coronary artery disease.

To determine the spontaneous progression of valvular aortic stenosis and to delineate clinical factors related to progression, a longitudinal study, including 49 patients (aged 16 to 81 years), was performed. All patients had auscultatory findings of aortic stenosis and multiple Doppler echocardiograms separated by at least 11 months. Rapid progression of aortic stenosis was defined as an increase of maximal instantaneous pressure gradient by > or = 10 mm Hg per year. During a mean follow-up period of 32 months (11 to 66 months), maximal pressure gradient rose from 38 +/- 15 to 60 +/- 20 mm Hg in the entire study population, resulting in a median increase of 7.2 mm Hg per year. In 21 patients (43 percent), an increase of > or = 10 mm Hg per year was found; in this subgroup with rapid progression, patients were older (64 vs 53 years, p < 0.01) and coronary artery disease was more prevalent (38 percent vs 7 percent, p = 0.01). We conclude that nearly half the patients with initially mild to moderate valvular aortic stenosis reveal a progression of > or = 10 mm Hg per year.

Adolescent↗
PubMed1989

A prospective randomized trial of low molecular weight heparin-DHE and conventional heparin-DHE (with acenocoumarol) in patients undergoing gynaecological surgery.

The antithromboembolic efficacy of once a day low molecular weight heparin in fixed combination with dihydroergotamine (LMWH-DHE) was compared with conventional heparin-DHE in combination with Acenocoumarol (heparin-DHE/A) in 191 patients undergoing gynaecological surgery. LMWH-DHE proved equally effective in preventing thromboembolic complications, with a similar incidence of postoperative bleeding and side effects. Deep vein thrombosis occurred once in each group and one non-fatal pulmonary embolism occurred in the LMWH-DHE group. The main advantage of LMWH-DHE was significantly better patient acceptance of the single daily subcutaneous injection as compared with the two injections of conventional heparin-DHE (P = 0.02). On the other hand, LMWH-DHE was associated with significantly increased incidence of intraoperative bleeding (P less than 0.02). The bleeding did not, however, cause any clinical problems. Discontinuation of therapy due to bleeding or pain at the site of injection occurred three times in each group. We consider the use of LMWH-DHE to be an attractive, economic and safe method of thromboembolic prophylaxis.

Acenocoumarol↗
PubMed1985

[Renovascular hypertension: surgery, dilatation or drugs?].

The effect of various therapeutic procedures (surgery, percutaneous transluminal dilatation and antihypertensive drugs) was analyzed in 161 patients with renovascular hypertension. The results show that each of the three methods effectively lowers blood pressure. However, marked differences in pretreatment clinical and laboratory data among the three groups were observed, which were most probably caused by different selection criteria before submitting the patient to a given therapeutic regime. The findings also demonstrate that, on the basis of the present analysis, a direct comparison between surgery, dilatation and medical therapy is not possible.

Adult↗
PubMed1985

Long-term experience in percutaneous transluminal dilatation of renal artery stenosis.

Percutaneous transluminal dilatation was attempted in 65 patients with renovascular hypertension. In five cases (8 percent), percutaneous transluminal dilatation could not be performed for technical reasons. In the remaining 60 patients (35 with atherosclerotic stenosis and 25 with fibromuscular dysplasia), both mean systolic and diastolic pressure fell immediately after percutaneous transluminal dilatation and remained significantly lower for a period of up to five years. Cure rates after a mean control period of 21.6 months were higher in patients with fibromuscular dysplasia (50 percent) than in those with atherosclerotic stenosis (29 percent). Improvement of blood pressure was observed in 32 percent of patients with fibromuscular dysplasia and in 48 percent of patients with atherosclerotic stenosis. Follow-up angiography in 33 cases showed occlusion of the dilated artery in two patients and recurrence of slight renal artery stenosis in nine patients. Successful redilatation could be performed in five of these cases. Furthermore, renal vein renin determinations were only of limited diagnostic or prognostic value. These results document the good long-term effect of percutaneous transluminal dilatation in patients with renal artery stenosis. Percutaneous transluminal dilatation should, therefore, be the favored procedure in patients with renovascular hypertension.

Adult↗
PubMed1985

Unilateral parenchymatous kidney disease and hypertension: results of nephrectomy and medical treatment.

In the present study 43 patients with unilateral parenchymatous kidney disease and hypertension were investigated. 20 patients were nephrectomized, 23 treated with antihypertensive drugs. Both therapeutic approaches showed an excellent and sustained blood pressure-(BP)-lowering effect. BP fell from 185 +/- 27/116 +/- 13 to 138 +/- 20/86 +/- 10 mm Hg in the operated and from 194 +/- 32/116 +/- 13 to 149 +/- 22/95 +/- 12 mm Hg in the medically treated patients after 2 and 6 weeks, respectively (p less than 0.001). BP was 142 +/- 16/89 +/- 11 and 136 +/- 16/90 +/- 10 mm Hg at the long-term follow-up in the 2 subgroups. In the operated group 70% (n = 14) were cured, 20% (n = 4) were improved and 10% (n = 2) unimproved. In the medically treated group 65% (n = 15) were normotensive, 26% (n = 6) improved and 9% (n = 2) treatment resistant. No significant correlation between postoperative BP reduction and lateralization of renin secretion (PRA-ratio greater than or equal to 1.5) was found. Although cured patients showed a higher mean PRA-ratio, 4 patients with a PRA-ratio less than 1.5 were cured (n = 2) or improved (n = 2) postoperatively. Our results document an excellent and sustained antihypertensive effect of both nephrectomy and medical treatment in patients with unilateral parenchymatous kidney disease and hypertension. They further limit the predictive value of renal venous renin determination in the preoperative workup.

Adolescent↗
PubMed1985

A simple and effective method to teach patients about high blood pressure and obesity.

It is an open question whether information about hypertension and obesity increases compliance with therapy. Nevertheless, patients increasingly demand precise but simple and comprehensive information. A simple slide programme is described which can be demonstrated in any waiting room. The learning effect was assessed in 1083 subjects, of whom 485 had seen the programme completely; 256 subjects served as controls. The percentage of subjects with good or excellent knowledge about hypertension and obesity rose from 22.8% in the controls to 64.2% in the experimental group. Age was the only factor influencing learning, but this was of no great importance in subjects under 70. In particular, social status did not have any significant effect on learning. This programme may be an ideal tool to inform patients about hypertension and obesity and to study the influence of information on compliance with therapy.

Age Factors↗
PubMed1985

Clinical evaluation of semiautomatic blood pressure devices for self-recording.

Sixteen semiautomatic blood pressure devices for self-recording were compared with a Hawksley random zero sphygmomanometer using three criteria for determination of accuracy: correlation analysis; mean differences; standard deviation of mean differences. Only one of the tested instruments showed excellent results, but three other devices had satisfactory accuracy of blood pressure recording. These devices could be recommended for self-recording by patients. Only minor differences were found between the devices as regards reliability and convenience in use.

Blood Pressure Determination↗