Search PubMed⌕ Search

Biomedical subjects

M Stauch

Publications and source records attributed to M Stauch.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Isotopic methods].

Explore the source record for details and available documents.

Arrhythmias, Cardiac↗
PubMed1984

[Radionuclide ventriculography in aortic and mitral valve insufficiency. Pre- and post-operative studies of valve replacement surgery].

Radionuclide ventriculography (RNV) is now a well-established procedure for the noninvasive evaluation of cardiac hemodynamics, including the detection and quantification of valvular regurgitation. 46 patients undergoing aortic or mitral valve replacement were examined by RNV pre- and postoperatively. The specificity of RNV in the diagnosis of aortic or mitral incompetence was high. All cases of moderate to severe aortic regurgitation were identified. This, however, was not true for mitral incompetence. A significant overlap between the left atrium and the left ventricle in the LAO view is held responsible for this decrease in sensitivity. The quantification of aortic regurgitation and the assessment of left ventricular function by RNV appears to hold promise in the preoperative workup. This diagnostic approach yields important additional information, which may be essential in the appropriate timing of surgical intervention. Aortic valve replacement for incompetence as well as for stenosis was accompanied by a significant improvement in global left ventricular ejection fraction. No postoperative change in ejection fraction was found in cases of mitral incompetence, while a slight increase was observed following operative therapy for mitral stenosis. The radioisotope findings were correlated to the results obtained by cardiac catheterization and noninvasive techniques such as echocardiography. The place of RNV in the pre- and postoperative management of valvular heart disease is delineated in this paper. It is of special value in the evaluation of aortic incompetence and may be an important diagnostic adjunct in the approach to the patient with mitral valve disease or aortic stenosis.

Adult↗
PubMed1983

Interobserver and intermethod variation in evaluation of regional wall motion of the left ventricle.

To determine the variation in the repeated evaluation of quantitative regional wall motion of the left ventricle (LV) from right anterior oblique (RAO) silhouettes, an intra- and inter-observer test was performed in 17 patients without wall motion abnormalities, using nine different methods of regional wall motion (RWM) analysis. The results were: 1. Around the cardiac apex and near the valve plane there are regions where the subjective contour delineation yields regional mean discrepancies up to 4-5 mm (2-3 mm, respectively, near the valves); while in the other regions the mean discrepancies are usually smaller than 1 mm. 2. Absolute regional contour discrepancies, calculated in mm, show only small differences in the various methods, applied for RWM analysis. 3. If these discrepancies instead are calculated as relative changes (in relative percent) of hemiaxial or segmental shortening or area diminution, the method applied is of great significance, since the length of the axes can vary considerably from method to method. 4. From all methods applied for RWM analysis, that of Mathes [10] (radial method) had the smallest average discrepancy. These results suggest, that the LV silhouette may be best defined in the anterior and inferior wall area, while in other regions subjective impressions of contour tracing may produce a considerable variation, which can be further enhanced by the method applied for RWM analysis. Methods that employ relatively large axes of as similar as possible length are therefore preferred.

Adult↗
PubMed1983

Assessment of left ventricular function from the mitral valve echocardiogram following positive and negative inotropic interventions.

The echocardiographically visualized mitral valve motion pattern has been shown to be related to left ventricular diastolic parameters and systolic performance. In order to analyze the influence of a negative inotropic agent (penbutolol, Betapressin) and a positive inotropic drug (AR-L 115 BS, Vardax) on the movement of the anterior mitral valve leaflet (aMV), the following motion phases of the aMV were determined in 23 patients following completion of diagnostic cardiac catheterization: DE slope, EF slope, the final closing velocity of the aMV (AC/BC slope), CE amplitude, AC interval, and PQ-AC interval. These values were compared to several hemodynamic parameters. In 13 patients (group I) control values were obtained under physiological conditions as well as during right atrial pacing at constant pacing rate in order to exclude changes in heart rate. Measurements were repeated under spontaneous heart rate and during atrial pacing following the application of penbutolol. In the other 10 patients (group II) the echocardiographic and hemodynamic data were obtained before and after the intravenous application of AR-L 115 BS. In addition, left ventriculography was repeated in 8 patients after the pharmacologic intervention. The investigations revealed changes in the mitral valve motion pattern following negative and positive inotropic interventions. The most marked changes occurred in the AC/BC slope, which declined significantly after beta blockade with penbutolol (means 300.1 mm/s vs. means 208.4 mm/s; p less than 0.01). This effect proved to be unaffected by heart rate: there was also a reduction of the closure slope after application of penbutolol during atrial pacing (means 343.1 mm/s vs. means 268.6 mm/s; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1982

Radionuclide ventriculography: a noninvasive method for the detection and quantification of left-to-right shunts in atrial septal defect.

The present investigation was undertaken to assess a new scintigraphic method for the diagnosis of left-to-right shunts due to atrial septal defect based on the differing stroke volumes of left and right ventricles and to compare it with oxymetric data. Radionuclide ventriculography was carried out after injection of 20 mCi 99mtechnetium-labeled red blood cells. Time-activity curves were obtained from the left and right ventricular regions, and the ratio (A) of end-diastolic-end-systolic count rate differences for the left and right ventricles was calculated. The left-to-right shunt (in percent of the pulmonary flow rate) is then given as 100 X (1 - A/1.43; 1.43 being the previously determined mean value of A in 66 normal patients. In 16 patients with an atrial septal defect and/or partial anomalous pulmonary venous connection a correlation of r = 0.81 was found between those shunts determined by the scintigraphic method and those calculated by oxymetric data. The specificity of the method and the sensitivity in detecting left-to-right shunts exceeding 30% are high. The method is practical and already widely used for determination of ejection fraction end-diastolic volume and other factors. The combination of this technique with other methods for shunt diagnosis such as gamma-fit analysis may prove of special value.

Heart↗
PubMed1981

Ultrastructure of platelets before and during atrial stimulation. Differences in the coronary sinus and aortic blood in patients with angina pectoris.

We studied 15 patients with strain-induced angina pectoris performing an ultrastructural analysis of platelets withdrawn simultaneously from the aorta and coronary sinus. In coronary sinus blood, all platelets exhibited shape changes with pseudopod formation but without degranulation. In the aortic blood we observed on average fewer shape changes of the platelets. During tachycardia stress, shape change formation did not increase in most patients. In three patients however, micro-aggregation of the platelets was observed only in the aortic blood. These patients had a paucity of risk factors. They also had fewer critical coronary artery stenoses compared with the other patients. We conclude that there may be minority among the patients with angina pectoris exhibiting hyper-aggregation of the platelets.

Angina Pectoris↗
PubMed1981

Evaluation of aortic and mitral valve regurgitation by radionuclide ventriculography: comparison with the method of Sandler and Dodge.

The present investigation was undertaken to introduce a quantitative scintigraphic method for evaluation of regurgitation and to compare it with the generally accepted quantitative method of Sandler and Dodge (Sandler et al., 1963). Radionuclide ventriculography was carried out after injection of 20 mCi 99mtechnetium-labeled red blood cells. Time-activity curves were obtained from the left and right ventricular regions. The ratio (A) of end-diastolic-end-systolic count-rate differences for the left and right ventricles was calculated. The ratio (A) was compared with a hemodynamic ratio (Ah) determined after the method of Sandler and Dodge (1963) with the stroke volume of the left ventricle measured angiographically, and the stroke volume of the right ventricle measured by thermodilution. In 33 patients with aortic and mitral valve regurgitation we found a correlation of r = 0.75 between (A) and Ah). Due to a broad range of normal values of (A) the sensitivity of the scintigraphic method is low. The specificity seems to be high, however, since in 64 patients with all types of heart diseases there were no false positive results. Comparing the described scintigraphic method with other modern or generally accepted methods, the principal advantages are noninvasiveness, good practicability, and the fact that important additional information about the functional state of the heart is gained. This is important in follow-up studies in patients with chronic valvular incompetence. It seems that this method will become a valuable supplement to heart catheterization in the diagnosis of valvular heart disease and may partially replace invasive methods for measuring the regurgitation fraction.

Adult↗
PubMed1981

Effects of AR-L 115 BS on hemodynamics and contractility of the heart in cardiac patients.

During diagnostic heart catheterization and/or coronary angiography 25 patients with coronary heart disease(21 pts), congestive cardiomyopathy (3) and aortic valve incompetence (1) were examined in two studies: 7 patients received 150 mg 2-[(2-methoxy-4-methylsulfinyl)phenyl]-1H-imidazol[4,5-b]pyridine (AR-L 115 BS) orally. The hemodynamic parameters were recorded for 1 h. There was a significant increase in heart rate and dp/dt max and a decrease in stroke volume. There was no significant change in cardiac output. Left ventricular diastolic pressure was reduced, but was statistically not significant. 18 patients received 0.7 mg/kg AR-L 115 BS by injection into the pulmonary artery after control ventriculography of the left ventricle. Ventriculography was repeated 10-12 min later. Acute hemodynamic changes comprised a significant increase in heart rate and cardiac output, and a significant decrease in LVEDP, pulmonary artery mean pressure and LV systolic pressure. The ejection fraction was not consistently improved but showed a definite increase in patients with myocardial ischemia at rest and in patients with cardiomyopathy. An acute antianginal effect was observed in two cases and explained by a marked peripheral vasodilation.

Cardiac Output↗
PubMed1981

[Quantitative left ventriculography: comparative investigations in normal patients (author's transl)].

In 17 patients with no demonstrable cardiac disease, analysis of the ventriculogram with respect to regional wall motion was performed. These normal patients formed the basis for establishing the normal ranges for 6 different methods of regional wall motion analysis (3 chord, 2 radial, 1 area). In each method, analysis of regional shortening showed a Gaussian distribution. The normal range of a segment was defined as the mean +/- 2 standard deviations, hence comprising 95% of normals. Comparing our 6 normal ranges with the ranges as initially described by their respective authors, the general shape of our curves was largely in agreement with the original curves. In detail, the amount of regional shortening showed some discrepancies, and only our normal range curve, calculated according to the method of Leighton, was highly comparable to the original range of the author, as well as to the one of Brower. Reasons for the discrepancies using other methods may be accounted for by different catheter conditions, different patient material and a subjective variation in delineating the contours of diastole and particularly of systole. It is concluded that normal ranges of a method for wall motion analysis cannot be applied directly from the literature without their prior verification under the special conditions of the angiographic technique and evaluation used.

Heart Ventricles↗
PubMed1981

[Assessment of left ventricular regional function by means of radioactive isotopes (author's transl)].

Extensive analysis of heart function by scintigraphy yields global parameters of ventricular volumes and their changes during the heart cycle (ejection fraction, enddiastolic and endsystolic volumes, velocity of contraction and relaxation). Additionally, information regarding localized disorders of wall motion may be obtained in a qualitative and quantitative manner by the parameters "phase" and "amplitude". These parameters can be computed from regional time-activity curves by Fourier analysis. The radionuclide ventriculogram at rest is suitable for the detection and follow-up of asynergies caused by acute and chronic infarction. In can also be used as a method of distinguishing between reversible and irreversible asynergy by therapeutical intervention (intervention ventriculography). Abnormalities of regional wall motion which develop during exercise may indicate hemodynamically relevant coronary artery stenoses.

Cardiac Output↗
PubMed1981

[Quantitative evaluation of regional and global parameters of left ventriculography with different methods in an intra- and interobserver test (author's transl)].

In 17 patients without evidence of regional wall motion abnormality a determination of the variation of global and regional parameters of two contour delineations was attempted by the same (intraobserver) and by an independent observer (interobserver). In the intraobserver comparison all computed comparison all computed parameters showed excellent correlation coefficients: enddiastolic volume (EDV) r = 0.97, endsystolic volume (ESV) r = 0.94, ejection fraction (EF) r = 0.93. In the interobserver comparison, the correlations were slightly lower (EDV: r = 0.94, ESV: r = 0.93, EF: r = 0.85). Absolute differences in volumes and ejection fractions were for the EDV 3.0 +/- 11.8 ml (+/- 1 SD), for the ESV 2.6 +/- 4.9 ml, and for EF 1.9 +/- 4.1%. Additionally, the three contour tracings were subjected to an analysis of regional wall motion using nine different methods. With most of the methods applied, the analysis showed areas near valves and the cardiac apex, where small changes in contour tracings resulted in statistically significant differences in wall motion (p less than 0.05). Therefore, using each method described, it was possible to determine, which regions demonstrated the greatest variation in interpretation of quantitative regional wall motion. Finally we conclude, that enddiastolic and endsystolic volumes and ejection fraction can be subjected to repeated estimation by the same or an independent observer with sufficient accuracy.

Cardiac Volume↗
PubMed1980

[Fendiline and isosorbide dinitrate in coronary heart disease (author's transl)].

In a randomized cross-over double-blind study of 30 out-patients with true angina the efficacy of fendiline and isosorbide dinitrate (ISDN) was compared. In randomized order the patients daily took either 3 X 50 mg fendiline or 2 X 20 mg ISDN (plus 1 placebo tablet). Each treatment period lasted for six weeks. Ergometric tests were performed at the onset of the study and at intervals of three weeks. The main criterion for the efficacy of the treatment was a change in S-T segment (at 0.06 s after the QRS). With either drug there occurred a statistically significant reduction in S-T depression and in the frequency of anginal attacks during the first treatment period. But there was a difference between the two drugs: Whereas with ISDN a marked reduction in S-T segment depression was observed after three weeks, this effect slightly receded in the second part of the treatment period, while with fendiline the reduction in S-T depression continued over the entire treatment period. There was no significant difference between the two drugs as to side-effects or tolerance.

Adult↗