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Biomedical subjects

U Tebbe

Publications and source records attributed to U Tebbe.

At least 163 records · Page 9Linked to original sources
PubMed1987

The therapy of acute myocardial infarction: current state of the art.

For decades management of acute myocardial infarction (AMI) consisted of bed rest, oxygen, prevention for thromboembolic complications, and treatment of arrhythmias and heart failure. In the last years a more aggressive treatment of AMI has been developed, based on the following three basic principles: (1) Mortality of patients with AMI is determined by the infarct size and the degree of left ventricular dysfunction. (2) The time interval between the onset of coronary occlusion and any intervention to limit infarct size is brief and takes usually not more than three to four hours. (3) After the acute phase of infarction a lot of patients remain at high risk of fatal coronary events, i.e. reinfarctions. The angiographic findings during the first hours of AMI showed in about 80% of patients an obstructive coronary thrombus and led to efforts to dissolve the offending thrombi. The demonstration that coronary thrombi can be lysed in about 80% of cases within 60 minutes after the intracoronary injection of thrombolytic agents (streptokinase or urokinase) has boosted the reperfusion therapy in AMI in the hope that ischemic myocardium might be salvaged. Intracoronary infusion of thrombolytic agents however, can be applied only in a minority of patients with AMI because coronary angiography and a skilled team of investigators are required, therefore a short-time intravenous high dose streptokinase infusion was developed. In the meantime two large double blind randomized trials (ISAM and GISSI) could demonstrate a reduction in hospital mortality in AMI especially by early treatment with intravenous streptokinase. Conventional thrombolytic agents produce a systemic lytic state with the possibility of hemorrhage, therefore recombinant tissuetype plasminogen activator (rt-PA) and two other drugs, acylated streptokinase and pro-urokinase, were developed with the aim of inducing coronary thrombolysis without severe systemic lytic state, but the efficacy of these new drugs remains to be demonstrated in randomized trials versus conventional thrombolytic agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1987

Changes in left ventricular diastolic function during exercise in patients with coronary artery disease.

In 10 controls and 43 patients with coronary artery disease (CAD) left ventricular (LV) diastolic pressure-volume (P-V) curves were obtained from biplane ventriculograms and simultaneous high fidelity pressure measurement at rest and during bicycle exercise. During exercise ventriculography 20 patients had angina pectoris, and 16 patients were asymptomatic. At rest there were no akinetic segments in 28 patients, and at least one akinetic segment was found in 15 patients. Shifts in the diastolic P-V relationship with exercise were quantitated from the constants a and b of the linear log P-V relationship. In the control group a and b did not change significantly, but in all CAD groups a significant decrease in a and a significant increase in b were observed during exercise. While no patient with angina had an unchanged diastolic P-V relationship, as many as 12 patients had significant P-V shifts in the absence of angina. A similar correlation was found for the diastolic P-V alterations and the exercise ECG. Fourteen patients without any ST-segment change during exercise showed significant P-V shifts, while no patient with signs of ischaemia in the ECG had an unchanged P-V curve. In another 20 patients with CAD the relative contribution of the Frank-Starling mechanism, diastolic compliance and the pericardium to the filling pressure rise during exercise was analyzed. Left ventricular and right atrial pressures--as an index of pericardial pressure--were measured simultaneously during rest and exercise ventriculogram. This was done when filling pressures exceeded 30 mmHg or when angina pectoris occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Evaluation of three methods for quantifying valvular regurgitation using gated equilibrium radionuclide ventriculography.

The non-invasive quantification of mitral and aortic regurgitation using the left-to-right stroke count ratio (SCR) calculated with gated equilibrium radionuclide ventriculography (RNV), is affected by the overlap of atria and ventricles and the consequent difficult definition of the ventricular regions of interest (ROI). Various solutions of the problem have been proposed. In this study we evaluated the results obtained with a technique based on visual inspection of the RNV images (variable ROI method--VRI) and those of two approaches which utilize functional images (stroke volume image method--SVI--and Fourier amplitude ratio--FAR), by comparing them with the invasive quantification of valvular regurgitation according to Sandler et al. (stroke volume ratio--SVR). Forty patients (15 controls and 25 valvular patients) were studied. In the control group the range of the SVR was 0.81 +/- 1.11 (mean +/- 1 SD = 1.01 +/- 0.08). The SCR was 0.83-L28 (1.03 +/- 0.15) with VRI, 1.10-1.15 (1.30 +/- 0.14) with SVI and 1.11-1.58 (1.35 +/- 0.17) with FAR. The correlations between SVR and SCR were r = 0.47 (P less than 0.05), r = 0.62 (P less than 0.001) and r = 0.55 (P less than 0.01) respectively with VRI, SVI and FAR. The SCR of valvular patients fell in the range of controls in 11/25 using VRI, 6/25 using SVI and in 4/25 using FAR. This overlap was present in 2/25 with the invasive quantification. Irrespective of the method used, a reliable assessment of the valvular regurgitation was not possible in two patients with severely depressed left ventricular function. We conclude that the use of techniques based on functional images clearly improves the effectiveness of the non-invasive quantification of valvular regurgitation with the SCR even if this cannot be regarded as a substitute for invasive quantification and has a limited reliability in particular groups of patients.

Adult↗
PubMed1987

[Right ventricular stroke volume--comparison of various methods of angiography and equilibrium radionuclide ventriculography].

In 21 patients with various heart diseases RVEF was measured angiographically and by radionuclide ventriculography. Using biplane angiocardiography evaluation was performed by 7 different methods (Simpson's rule, Dogde, Arcilla, Ferlinz, Duebel). Using equilibrium RNV, evaluation was performed by 9 modifications of analysis. Problems were evident to separate the right atrium from the ventricle and to define the site of the pulmonary valve. The results show that when using the various methods of angiography considerable variations of the absolute volumes occur, but least so with RVEF. When using RNV with one single enddiastolic ROI, the RVEF was much too low. By means of the enddiastolic/endsystolic Double-ROI-method a good agreement with angiography was found, with correlation coefficients up to r = 0.85. There was only a minor effect of background correction.

Adult↗
PubMed1987

Fatty acid metabolism in symptomatic patients with mitral valve prolapse but without coronary artery disease--comparison with 201Tl myocardial perfusion scintigraphy.

Using 123I-omega-heptadecanoic acid (HDA) and 201Tl, respectively, myocardial fatty acid metabolism and perfusion were studied in 51 symptomatic patients with mitral valve prolapse (MVP) as diagnosed by ventriculography, and no evidence of coronary artery disease. Twelve subjects with normal coronary arteries and normal ventriculogram served as a control group for the evaluation of elimination kinetics of HDA. In the control group, the mean elimination half-life was 26.1 +/- 3.6 min, whereas the patients with MVP had a mean value of 25.0 +/- 6.4 min. In patients with MVP, a high incidence concerning abnormalities of accumulation and/or elimination of HDA occurred, namely accumulation defects in 31% and both prolonged and shortened elimination half-lives in 16% and 29%, respectively. Myocardial perfusion scintigraphy using 201Tl showed abnormalities in 76%. Correlations were found between decreased uptake of HDA and prolonged elimination half-life as well as defects by 201Tl, presumably due to ischemia based on small-vessel disease or abnormalities of cellular metabolism.

Adult↗
PubMed1986

Fibrinolytic activity in renal venous blood in man.

In 50 patients without renal insufficiency, fibrinolytic activity, as reflected by euglobulin lysis time, was determined in blood obtained from the renal veins, the renal artery and a peripheral vein. Fibrinolytic activity was found to be significantly higher in the renal veins than in the renal artery and the peripheral vein. Other coagulation and fibrinolysis parameters did not show such differences. In addition, a patient with acute oligoanuric renal failure was investigated. This patient demonstrated reduced overall fibrinolytic activity, but there were no differences between the activity in the blood of the renal veins and that of the renal artery or peripheral vein. It seems, therefore, that the kidneys release plasminogen activators into the systemic circulation. This may be decreased in renal failure, probably contributing to the well-known diminished fibrinolysis in some kidney diseases.

Acute Kidney Injury↗
PubMed1986

[Acute coronary angiography in therapy-refractory angina pectoris].

UNLABELLED: Emergency coronary angiography was performed in 188 patients with treatment-resistant unstable angina. Criteria analysed were: duration of angina less than 72 h; angina despite heparin and nitroglycerin infusion; no significant S-T segment elevation in the ECG; creatine-kinase rise up to 150 U/l. Coronary heart disease (CHD) was found in 130 patients (group A). In 47 of them a recent coronary occlusion was demonstrated angiographically (main stem: 1; anterior interventricular branch: 8; circumflex branch: 27; right coronary artery: 11 patients). An at least 90% occlusion of one coronary artery was found in 58 patients. A 75% stenosis of several vessels was found in 25 patients making it impossible to identify the vessel that had caused the angina. A bypass operation was performed in 62 patients within two weeks. During the acute coronary angiography, intracoronary streptokinase infusion was performed in 11 (success rate 55%), percutaneous transluminal coronary angioplasty in 26 (success rate 88%). In 58 patients (group B) CHD was excluded. The final diagnosis in these was: mitral valve prolapse (31); pericarditis (6), dilated cardiomyopathy (3); coronary anomaly (3); muscle bridge in the anterior interventricular branch (2): normal (13). CONCLUSION: It is not possible to decide with certainty, in the absence of typical infarction signs in the ECG and clinically, whether treatment-resistant angina is due to CHD or other causes. Acute coronary angiography is indicated in such cases, because even without S-T segment elevation an acute coronary occlusion is present in 25%, and in 50% of cases an acute therapeutic intervention is indicated.

Adult↗
PubMed1986

Fatal outcome of aortocoronary bypass grafting in a 62-year-old man with unsuspected coronary arteritis.

A 62-year-old man was admitted to our hospital with unstable angina. The coronary arteriography showed the occlusion of the left anterior descending artery and other stenotic lesions. The patient underwent an aortocoronary bypass operation, but unfortunately he did not survive. Surprisingly, the necropsy revealed him to be affected by an inflammatory process, involving the aorta and the coronary arteries. According to the clinical history and examination, the findings at necropsy and the histologic picture, the diagnosis of Takayasu's arteritis appears the most probable. Coronary arteritis has to be considered as a possible etiology of ischemic symptoms also in subjects who appear affected by typical atherosclerotic ischemic heart disease.

Angina Pectoris↗
PubMed1986

[Occlusion of the common trunk of the left coronary artery. Physiopathological features and clinical findings].

The total occlusion of the left main coronary artery is rarely observed (approximately 0.05% of coronary angiographic studies). We have tried to draw the clinical and pathophysiological outline of this condition, starting from our experience and reviewing the published reports. A hard selection, principally by the high mortality in patients with left main coronary stenosis, limits the number of those who present total occlusion. These subjects show a remarkable variability in their clinical presentation. It is not possible to find out a significant correlation with a single risk factor, clinical manifestation or electrocardiographic picture. Therefore, these patients cannot be distinguished from other subjects affected by severe atherosclerotic ischemic heart disease. The angiographic finding of a dominant right coronary artery is most frequent. A rich collateral circulation to the left coronary is usually observed. From a pathophysiological point of view, the efficiency of coronary collateral circulation is confirmed by the significant correlation of its extent with the left ventricular function. An important role is also played by the rate of progression of left main stenosis in total occlusion and by the presence of right coronary lesions. Even if statistical evidence is still lacking, surgical treatment is unanimously indicated and achieves satisfying results. The use of nonsurgical recanalization techniques, such as intracoronary thrombolysis and transluminal angioplasty, may be lifesaving in those patients in whom left main coronary occlusion suddenly occurs.

Angiography↗
PubMed1985

[Valvuloplasty and peripheral angioplasty with coronary dilatation catheters].

The further development of coronary balloon catheters has encouraged their use for dilating small vessels of other organs and stenoses in larger vessels not passable by conventional catheters. The technique was used successfully as a primary intervention in two stenoses of the external carotid artery preparatory to extra-intracranial anastomosis, in four anastomotic stenoses in three patients with Blalock-Taussig anastomosis, and in a subtotal anastomosis of a Cimino shunt. After failed dilatation attempts with a standard dilatation catheter in three patients with four renal artery stenoses and two with subclavian artery stenosis, coronary angioplasty catheters successfully dilated the stenoses. In two infants with severe valval aortic stenosis and left-heart failure, retrograde transluminal balloon dilatation reduced the transvalval gradient from 70 to 30-40 mm Hg.

Adolescent↗
PubMed1985

Mitral valve prolapse in the ventriculogram: scintigraphic, electrocardiographic, and hemodynamic abnormalities.

Patients with mitral valve prolapse (MVP) frequently have chest pain, which may be difficult to differentiate from angina pectoris in coronary artery disease (CAD). We performed resting and exercise ECGs, pulmonary arterial pressure measurements, radionuclide ventriculography (99mtechnetium), and perfusion scintigrams (201thallium) in 56 patients with angiographically proven MVP and no CAD. Pathological results were obtained in 31% of exercise ECGs, 33% of pulmonary arterial pressure measurements during exercise, 22% of radionuclide ventriculographies, and in 75% of thallium perfusion scintigrams. A significant correlation in pathological results was found only between exercise ECG and both radionuclide ventriculography and pulmonary arterial pressure measurements. Because of the high prevalence of false-positive perfusion scintigrams in patients with typical or atypical chest pain, the use of exercise 201Tl imaging as a screening method to separate patients with MVP from those with CAD will not be appropriate. The variability of cardiac abnormalities in our patients with MVP and angiographically normal coronary arteries suggests that the MVP syndrome may represent a variable combination of metabolic, ischemic, or myopathic disorders.

Coronary Disease↗
PubMed1985

Underestimation of left-ventricular ejection fraction by radionuclide ventriculography in patients with aneurysm.

The left-ventricular ejection fraction (LVEF) of 72 patients with aneurysm of the anterior wall was measured by multiple gated blood pool acquisition (MUGA) in the anterior and left anterior oblique (LAO) positions, and by cineangiography (CA) in right anterior oblique (RAO) and LAO projections of 30 degrees and 60 degrees, respectively. The LVEF was overestimated by CA in the LAO projection and by MUGA in the anterior position, but underestimated by CA in the RAO projection (6.1 percentage points) and by MUGA in the LAO position (6.2 percentage points). In 50 patients without aneurysm, no systematical error occurred using MUGA. The underestimation of the LVEF in patients with aneurysm by MUGA in the LAO position is due to differences of photon attenuation in various parts of the cardiac blood pool. This systematical error can be overcome by biplane MUGA.

Cardiac Output↗
PubMed1985

[Follow-up of patients with anterior wall aneurysms using radionuclide ventriculography].

32 patients with a large anterolateral aneurysm were studied by using biplane ventricular angiography and rest and exercise radionuclide ventriculography (gated-blood-pool method). The correlation coefficient of biplane ejection fraction by angiography and radionuclide ventriculography was poor (r = 0.65), but repeated investigations and interobserver comparison showed nearly identical values, therefore we used the gated-blood-pool method (GBP) for follow-up investigations in patients with an aneurysm of the anterolateral wall. 11 patients were studied before and 17 +/- 6 months after left ventricular aneurysmectomy. Resting ejection fraction (LVEF) increased significantly from 28 +/- 8 to 38 +/- 8% (p less than 0.005), but exercise LVEF did not. In 21 patients with medical therapy the second GBP measurement after 16 +/- 6 months showed so significant changes in biplane LVEF (33 +/- 9 and 31 +/- 7%, respectively). During exercise LVEF remained unchanged after aneurysmectomy but increased slightly by 5% (p less than 0.05) in the medically treated group. The regional wall motion was unchanged in patients with medical therapy, but after aneurysmectomy there was a significant increase in local ejection fractions in the anterolateral, apical and posterolateral region. The gated-blood-pool methods is suitable for the determination of left ventricular function in patients with anterolateral aneurysm and may be used for follow-up studies. Left ventricular aneurysmectomy is effective in improving resting ventricular function, whereas in patients with medical therapy LV function remains unchanged.

Cardiac Output↗
PubMed1984

Analysis of left ventricular regional motility: a comparison of different methods.

Multiple gated blood pool (MUGA) and contrast ventriculographic studies were performed within 24 h in 80 patients, 20 with 120 normokinetic wall segments and 60 with wall motion abnormalities in 239 of 360 wall segments. Three methods of evaluation of the radionuclide ventriculograms were compared with the results of the biplane contrast ventriculography which served as a standard: (1) qualitative analysis of the cine mode, (2) analysis of parametric scans (amplitude and phase images) and the phase histogram obtained by Fourier analysis, (3) quantitative determination of regional ejection fraction. Normal values were obtained from 20 patients with normal wall motion in the contrast angiogram. The overall sensitivity for the detection of wall motion abnormalities of high degree was 96% for method 1, 95% for method 2, and 90% for method 3, for those of low degree 72% for method 1, 63% for method 2, and 75% for method 3. Combining methods 2 and 3 the sensitivity was increased to 99% for high grade and to 81% for low grade wall motion abnormalities. The two methods showed a complementary effect because of different sensitivities in dependence of the localization of the wall motion abnormality. Although a high efficiency for the evaluation of left ventricular function was provided by the qualitative analysis of the cine mode the combination of Fourier analysis and the determination of regional ejection fraction should be preferred. It increases the sensitivity for the detection of wall motion abnormalities. Moreover, it offers quantitative data which improve the reproducibility and decrease the observer variability.

Angiography↗
PubMed1984

[Occlusion of the right coronary artery with acute right heart infarct and cardiogenic shock].

In a 42-year-old patient with an acute inferior infarction the right coronary artery was recanalised by intracoronary streptokinase 4 hours after the onset of symptoms. In spite of early reperfusion the patient developed an extensive myocardial infarction and died three days later from cardiogenic shock. Autopsy revealed an almost complete necrosis of the right ventricle including the inferior interventricular septum and the adjacent left ventricular wall. Diagnostic and therapeutic problems in the so-called dominant right ventricular infarction are discussed.

Adult↗