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Biomedical subjects

U Tebbe

Publications and source records attributed to U Tebbe.

At least 145 records · Page 8Linked to original sources
PubMed1989

Contrary effects of acetylcholine on coronary arteries and aortocoronary venous grafts in man.

The endothelium-dependent vasomotor responses differ in arteries and veins, and the transfer of veins into the arterial circulation by venous grafting may change their endothelial function. The purpose of this study was to examine the responses to acetylcholine in aortocoronary venous grafts of coronary arteries in man which may indicate differences in the endothelial function of these vessels. Five patients with venous grafts (12 to 72 months after implantation) and five patients without any angiographic evidence for coronary artery disease (controls) were examined. The effect of local infusions of acetylcholine (7-70 nmol min-1) on the vessel diameters was assessed by quantitative angiography. In controls, acetylcholine caused no consistent reaction, but in patients with venous grafts the arterial segments distal to the bypass anastomoses were contracted (7 nmol min-1: 82 +/- 2%; P greater than 0.01). We observed that aortocoronary venous grafts reacted differently to acetylcholine compared with the coronary arteries (P less than 0.05): a slight but not significant dilatation of the venous graft occurred (7 nmol min-1: 103 +/- 1%). The contraction of atherosclerotic coronary arteries of patients with aortocoronary venous grafts is in accord with the assumption of a loss of endothelium-dependent vasodilatation in coronary artery disease. The cholinergic influence on the vasomotor control of venous grafts seems to be either of little importance or less affected by atherosclerotic endothelial lesions than in coronary arteries.

Acetylcholine↗
PubMed1989

[Use of the autoperfusion catheter in acute coronary occlusion within the scope of percutaneous transluminal coronary angioplasty (PTCA)].

The procedure of an autoperfusion catheterization after acute coronary occlusion by dissection during percutaneous transluminal coronary angioplasty (PTCA) is described. Multiple side holes proximal and distal to the dissection allow passive myocardial perfusion only by systemic blood pressure. In the case presented, the catheter immediately reestablished coronary blood flow and thereby produced resolution of symptoms and myocardial ischemia. This easy procedure made it possible to perform the subsequent coronary bypass operation as a controlled revascularization and it prevented myocardial necrosis.

Angioplasty, Balloon↗
PubMed1988

[Follow-up after dilatation of congenital and acquired aortic stenosis].

Until 31 December 1987, a total of 85 transfemoral balloon valvuloplasties (TBV) had been performed for aortic valve stenosis, on 25 patients with noncalcified congenital and 58 (aged 66 +/- 10 years) with acquired (calcified) stenosis. The procedure had to be repeated in two infants because of early re-stenosis. The systolic transvalvular pressure gradient was reduced from 93 +/- 29 (mean +/- SD) to 51 +/- 20 mm Hg in acquired stenoses, and from 87 +/- 24 to 44 +/- 15 mm Hg in congenital stenoses. Invasive pressure measurements in 16 patients with acquired stenosis 3-11 months (mean of 8 months) post-TBV demonstrated partial or complete re-stenosis in all patients. In contrast, only 3 of 17 patients with congenital stenosis had significant re-stenosis 4-38 months (mean of 16 months) after TBV. These results demonstrate that TBV gives similar immediate results in acquired, calcified and congenital, non-calcified aortic stenosis. However, the intermediate and long-term results are much better in the congenital form, because re-stenosis is rare, whereas the primary success failed to persist in any of the patients with the acquired form.

Adolescent↗
PubMed1988

[The dose of intracoronary urokinase infusion in acute myocardial infarct].

In 11 patients with acute myocardial infarction (mean age 52 +/- 6 years) coronary angiography was performed 4.5 +/- 3.6 h after the onset of symptoms. The infarct-related artery was in 7 cases the right coronary artery and in 4 cases the left anterior descending branch of the left coronary artery. The infarct-related artery showed total or subtotal occlusion and no perfusion (Thrombolysis in Myocardial Infarction trial (TIMI) grade 0 or 1). In 7 cases Urokinase was infused intracoronarily at a dosage of 250,000 IU over 30 min, but in only 1 case partial reperfusion was achieved. However, all patients treated with 500,000 IU Urokinase over 30 min or 1 Mill IU over 60 min had successful reperfusion (TIMI grade 2 or 3). Thus, it appears that 500,000 IU up to 1 Mill IU of Urokinase over a period of 30 to 60 min is adequate for intracoronary thrombolysis in patients with acute myocardial infarction.

Adult↗
PubMed1988

[A decline in hospital mortality in acute myocardial infarct during the last 10 years. An effect of acute intervention?].

The decline in hospital mortality after myocardial infarction was analyzed retrospectively in a cohort of 2147 consecutive patients with acute myocardial infarction, admitted to an University Hospital between 1978 and 1987. During this period the percentage of patients who had acute active interventions (thrombolysis, aortocoronary bypass surgery, percutaneous transluminal coronary angioplasty) increased from 6% (in 1978/79) to 50% (in 1986/87). During that same period, conventional treatment of acute myocardial infarction and the provisions for emergency admission and intensive care remained unchanged. At the same time there was a significant reduction in overall mortality from 29% (1978/79) to 17% (1986/87) (P less than 0.001). This decrease was especially marked for males (from 27% to 13% in the respective periods), and in patients with anterior-wall infarction (34% and 16%, respectively). These changes cannot be explained by differences in group characteristics. The main cause for the distinct reduction in hospital mortality of this cohort was the introduction and expansion of acute interventions.

Age Factors↗
PubMed1988

Coronary arterial embolism due to valvular debris after percutaneous valvuloplasty of calcific mitral stenosis.

A 74-year-old woman with refractory congestive heart failure due to long-standing calcific mitral stenosis who refused surgical intervention was treated with percutaneous balloon valvuloplasty. After an uneventful procedure, hemodynamic results were satisfactory with an increase in the mitral valve area from 0.4 to 1.1 cm2. Five hours after the procedure, the patient had a bout of vomiting followed by pulmonary aspiration. Electrocardiography, and in the further course, creatine kinase MB elevation, showed anterior myocardial infarction. Necropsy disclosed embolic material in the mid left anterior descending artery which unequivocally consisted of valvular material. This case demonstrates embolism of valvular debris as a life-threatening, procedure-related complication of percutaneous valvuloplasty of calcific mitral stenosis.

Aged↗
PubMed1988

Significance of gated equilibrium radionuclide ventriculography in quantification and follow up of valvular regurgitation.

In order to evaluate the significance of gated equilibrium radionuclide ventriculography (RNV) for non invasive quantification of valvular regurgitation and follow up, various approaches were tested concerning accuracy and reproducibility. By using in vitro labeling of red blood cells and extending the acquisition time, a clear reduction of dispersion was obtained in patients without valvular insufficiency. Quantification of regurgitation directly from functional images (ventricular amplitude or stroke volume image) was clearly superior compared to the variable region of interest method. Employing functional images, reproducibility between two observers and between two independent measurements was excellent. Correlation to regurgitation values determined by cardiac catheterization was only moderate with all RNV approaches tested. RNV is limited in the absolute quantification of valvular regurgitation due to the variable overlap of right atrium and right ventricle. However, because of its high reproducibility, RNV is a non invasive technique suitable for intraindividual follow up of patients with valvular insufficiency.

Adult↗
PubMed1988

Acute haemodynamic effects of urapidil in patients with chronic left ventricular failure.

Urapidil, a new alpha 1-adrenoceptor blocking drug, has been shown to be effective in the treatment of hypertension. Ten normotensive patients with severe congestive heart failure were given Urapidil 25 mg i.v. twice in 15 min and the haemodynamic effects were measured. There was a significant fall in systolic blood pressure (-16%), mean blood pressure (-13%), left ventricular end-diastolic pressure (-38%), mean pulmonary artery pressure (-31%) and wedge pressure (-40%). Total peripheral resistance fell by 25%, whereas pulmonary arteriolar resistance did not change significantly. Cardiac output increased by 22%. The increase in cardiac output with decreasing peripheral resistance and LV pressures suggests that urapidil may be useful in the therapy of congestive heart failure.

Adult↗
PubMed1988

Intravenous recombinant tissue plasminogen activator (rt-PA) and urokinase in acute myocardial infarction: results of the German Activator Urokinase Study (GAUS).

The effects of recombinant tissue plasminogen activator (rt-PA) and urokinase on patency and early reocclusion of infarct-related coronary arteries were investigated in a single blind, randomized multicenter trial in 246 patients with acute myocardial infarction of less than 6 h duration. Both 70 mg of single chain rt-PA with an initial bolus of 10 mg and 3 million units of urokinase with an initial bolus of 1.5 million units were given intravenously over 90 min. The first angiographic study at the end of the infusion revealed a patent infarct-related artery (Thrombolysis in Myocardial Infarction trial [TIMI] grade 2 or 3) in 69.4% of 121 patients given rt-PA versus 65.8% of 117 patients given urokinase (p = NS). Among patients treated within 3 h from symptom onset a patent infarct-related artery was found in 63.9% of 72 patients given rt-PA versus 70% of 70 patients given urokinase (p = NS). There were five cardiac deaths in each group and one fatal intracranial hemorrhage in the rt-PA group. The in-hospital reinfarction rate was 8.9% versus 13.2% for patients treated with rt-PA and urokinase, respectively. There was no difference in left ventricular function at baseline and follow-up catheterization studies. Both drugs were well tolerated and there was no significant difference in cardiovascular or bleeding complications between the two groups. It is concluded that rt-PA and urokinase in the dosages used provide similar efficacy and safety in the treatment of acute myocardial infarction. Reocclusion during the first 24 h may be less frequent after urokinase treatment.

Adult↗
PubMed1988

[Increased primary success rate in coronary angioplasty using a guide wire with attached balloon (microprobe)].

In 15 cases of 350 consecutive coronary angioplasties conventional low profile balloon catheters did not traverse the stenosis or occlusion over the guide-wire. A balloon on a wire device ("Microprobe", 2 mm) passed the stenosis or occlusion easily with a good primary result in 14 cases. The angioplasty procedure could then be completed with a larger standard balloon catheter. Use of the balloon on a wire device expands the technical facilities of angioplasty and increases the primary success rate in technically difficult cases.

Angioplasty, Balloon↗
PubMed1988

[The cardioprotective effect of verapamil in acute percutaneous transluminal coronary angioplasty].

Verapamil improved the ischemic tolerance of the myocardium in experiments in animals. Therefore, 20 patients were examined during percutaneous transluminal coronary angioplasty (PTCA) of a proximal LAD stenosis in order to evaluate the ability of verapamil to improve the ischemic tolerance in man. Before the second dilatation, 1 mg verapamil was given intracoronarily to 10 patients, the other 10 patients received placebo ic. Before and after each of the three inflations, blood samples were obtained from the coronary sinus in five patients of each group to analyze the contents of lactate, pyruvate, and pH. Verapamil caused a significant prolongation of the inflation from 58 +/- 12 s to 83 +/- 20 s. This effect was persistent also during the following inflation (96 +/- 19 s). The onset of angina was delayed (p less than 0.05). ST-wave elevations and T-wave amplitudes were smaller after verapamil, in spite of the increased duration of inflation, as compared with the control group. The time until ST elevations of 0.1 mV occurred was increased from 17 +/- 3 s to 57 +/- 18 s (p less than 0.05). The increase in lactate in coronary sinus blood was less pronounced after verapamil (48% of control; p less than 0.05). Intracoronary verapamil before PTCA of the LAD improved the ischemic tolerance of the poststenotic myocardium significantly as evaluated by measurements of electrocardiographic and metabolic parameters. No side effects occurred during the injection of verapamil into the left coronary artery.

Adult↗
PubMed1988

[Intravenous infusion of recombinant tissue-type plasminogen activator (rt-PA) and urokinase in acute myocardial infarct: intermediate results of the G.A.U.S. study (German Activator Urokinase Study)].

The effects of recombinant tissue plasminogen activator (rt-PA) and urokinase on patency and early reocclusion of infarct-related coronary arteries were investigated in a single blind, randomised multicenter trial in up to now 125 patients with acute myocardial infarction of less than six hours duration. Both, 70 mg of single-chain rt-PA with an initial bolus of 10 mg, and 3 million U of urokinase with an initial bolus of 1,5 million U were given intravenously over 90 minutes. The first angiogram at the end of the infusion revealed a patent infarct-related artery (TIMI grade 2 or 3) in 68% of 62 patients with rt-PA vs. 63% of 63 patients with urokinase (n.s.). Twenty-four hours later patent infarct-related arteries occurred in the same frequency in the rt-PA group and in the urokinase group (71.5% vs. 74.6%, n.s.), although additional recanalisation procedures in sequence with the first angiography were performed more frequent in the rt-PA group. There were two cardiac deaths in either group. In-hospital reinfarction rate was 9.7% vs. 17.5% for patients treated with rt-PA and urokinase, respectively. Both drugs were well tolerated, no significant difference of cardiovascular or bleeding complications could be observed between the two groups. It is concluded that rt-PA and urokinase in the dosages used provide similar efficiency and safety in the treatment of acute myocardial infarction.

Adult↗
PubMed1987

A prospective placebo-controlled double-blind multicenter trial of intravenous streptokinase in acute myocardial infarction (ISAM): long-term mortality and morbidity.

Long-term mortality and morbidity of 1,741 patients with acute myocardial infarction, treated with intravenous streptokinase (1.5 million IU/h) or placebo, was assessed in a double-blind placebo-controlled trial (ISAM). At the 7 month follow-up, 94 (10.9%) of the 859 patients in the streptokinase group and 98 (11.1%) of the 882 patients in the placebo group had died; at an average follow-up of 21 months, 14.4% of the streptokinase group and 16.1% of the placebo group had died. The differences were not statistically significant. Long-term mortality was slightly higher in patients with anterior myocardial infarction and streptokinase treatment (20.1 versus 18.4%) and lower in patients with inferior myocardial infarction (10.2 versus 14.2%). Patients with previous myocardial infarction had a higher long-term mortality rate with streptokinase (34.9 versus 21.5% with placebo, p = 0.03). At 7 months, there were significantly more cases of reinfarction in the streptokinase group (7.2 versus 4.5%, p = 0.02). It is concluded that despite a significant limitation of infarct size by intravenous streptokinase, long-term mortality is only slightly reduced and reinfarction is significantly more frequent. Both findings suggest the need for complementary therapy such as revascularization procedures after thrombolysis.

Clinical Trials as Topic↗