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Biomedical subjects

E Grube

Publications and source records attributed to E Grube.

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

[Modification of myocardial function parameters by L- and D-penbutolol--an echocardiography, placebo-controlled double-blind study].

In order to study left ventricular contraction parameters of L-penbutolol and D-penbutolol (isopenbutolol) we evaluated TM-echocardiograms of 12 healthy volunteers at 30 and 60 minute intervals for 8 hours after oral administration of 40 mg L- and D-penbutolol and placebo. Three different observers determined end-systolic and end-diastolic dimensions, left ventricular shortening fraction (SF) as well as mean-, peak- and rate corrected circumferential fiber shortening (VCF) and calculated at each measuring point the difference from the control value (Delta). L-penbutolol demonstrated a typical beta-blocking effect with a significant (p less than 0.001) decrease of systolic (11.1 +/- 8.6 mm Hg) and diastolic blood pressure (6.7 +/- 4.6 mm Hg) and heart rate (10.0 +/- 7.4 bpm) as well as a significant (p less than 0.001) negative inotropic effect expressed by a decrease of SF (6.5 +/- 4.2%) and VCF-mean (0.40 +/- 0.15 circ/s), VCF-peak (1.04 +/- 0.61 circ/s) and rate corrected VCF (0.28 +/- 0.08 circ/s). However, we saw a similar but less distinct negative inotropic and chronotropic effect of D-penbutolol as compared to placebo. HR decreased by 5.3 +/- 6.2 bpm (p less than 0.001), SF decreased maximally by 5.0 +/- 3.2% (p less than 0.05), VCF-mean by 0.27 +/- 0.08 circ/s (p less than 0.001), VCF-peak by 0.71 +/- 0.31 circ/s (p less than 0.001) and rate corrected VCF by 0.22 +/- 0.04 circ/s (p less than 0.001). By means of TM echocardiography it was therefore possible to document a strong beta-blocking effect of L-penbutolol as well as a negative inotropic and negative chronotropic effect by the D-isomer of penbutolol.

Adult↗
PubMed1985

[Automatic contour detection in the 2-dimensional echocardiogram--studies in a general patient population].

In order to test the application of an endocardial contour finding algorithm in apical projections we examined 56 consecutive patients by 2-D echocardiography. According to the quality of the endocardial definition we graded the total patient population in 4 qualities, grade I being the best and grade IV being the worst echocardiographic image with multiple extracavitary and intracavitary artefacts. Following manual and automatic detection of LV endocardium in end-systole and end-diastole by 2 observers we calculated LV areas (cm2), volumes (ml), ejection fraction (%) and regional wall motion (% radial shortening and % area shrinkage) and determined the reproducibility of the two different endocardial definitions. In all echocardiograms with good endocardial visualisation (grade I and II; n = 31, 55%), in 9 out of 15 patients with grade III and 4 out of 10 patients with grade IV echocardiograms we could successfully apply the contour finding algorithm. The comparison between automatically and manually detected contours showed good correlations with small standard errors; however the reproducibility of data expressed by the interobserver variability (V) calculated on the basis of automatically found contours was significantly better as compared to the manually derived contours. (V manual contour = 4.8-8.5 versus automatic contours 0.63-0.68). The systolic volumes (manual versus auto) correlated with r = 0.93, SEE 8.3 ml; the end-diastolic volumes (manual versus auto) with r = 0.90, SEE 11.3 ml, the ejection fraction (manual versus auto) with r = 0.93, SEE 5.1%. The determination of regional LV wall motion demonstrated an agreement in 91% and a discrepancy in 9% of regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗
PubMed1984

[Computer assisted determination of left-ventricular contraction abnormalities using two-dimensional echocardiography. I. Analysis various study methods and determination of normal values].

In 181 patients without signs of heart disease we determined the normal contraction pattern of the left ventricle in the echocardiographic 2- and 4-chamber views by means of the shortening of 48 radiants and the changes of 5 pre-defined areas. We used an extracardiac fixed axis reference system and an intracardiac floating reference system. We also calculated in 68 of the patients the interobserver variability of the data in each evaluation method. We demonstrated that the range of normal contraction and the reproducibility in the area-change method with a floating axis system was smaller compared to the radial shortening method. The interobserver variability in the 4-chamber view was better than in the 2-chamber view. Using the intracardiac fixed reference system in both methods, deviation from normal and interobserver variability was not acceptable for the detection of left ventricular wall motion abnormalities in both apical views. In general, we could also demonstrate that the interobserver variability was better and the range of deviation was smaller in the apical 4-chamber view than in the 2-chamber view. The practicability and quality of the apical projections were superior to the parasternal projections in the long and short axis. We conclude from our studies that left ventricular wall motion abnormalities in the echocardiographic 2- and 4-chamber views could best be demonstrated by using an area-change method with an intracardiac floating reference system.

Arrhythmias, Cardiac↗
PubMed1984

[Quantitative, computer-aided determination of left ventricular contraction abnormalities in two-dimensional echocardiography. II. Application in patients with coronary heart disease].

In 105 selected patients with documented transmural myocardial infarction and segmental wall motion abnormalities in the 2-dimensional echocardiogram we determined the sensitivity, specificity and predictive accuracy of a semi-automatic computerized wall motion analysis method. The extent and localization of the LV-contraction abnormalities were documented by visual inspection of the 2-D echocardiograms by two experienced cardiologists and confirmed by angiographic and coronarographic findings. These findings were compared with computerized evaluation methods using an area-change method (5 areas) and a radial shortening method in a floating axis reference system. In the 2-chamber and 4-chamber views the area-change method was more sensitive (2-CH: 70% vs 49%, 4-CH: 79% vs 72%) and had a higher predictive accuracy (2-CH: 90% vs 87%, 4-CH: 86% vs 82%) than the radial shortening method. The specificity between the two methods was not different. In both views, however, we found distinct regional differences between the apex and the anterior and posterior wall. We conclude from our studies that in patients with myocardial infarction, computerized wall motion analysis in the 2- and 4-chamber views is accurate and reliable as compared to the visual diagnosis of two experienced observers. The area-change method in an intracardiac floating system seems to be superior to the radial shortening method.

Angiocardiography↗
PubMed1982

Kinetics and cardiac effects of propranolol in humans.

Six healthy volunteers received single 20-mg intravenous (IV) and 80-mg oral doses of propranolol on two occasions in random sequence. Serum propranolol concentrations were determined by gas chromatography in multiple samples drawn during 24 h after each dose. Mean (+/- SE) kinetic variables for IV propranolol were: elimination half-life (t 1/2 beta), 5.3 (+/- 0.6) h; volume of distribution, 2.3 (+/- 0.3) l/kg; total clearance, 4.9 (+/- 0.3) ml/min/kg; predicted extraction ratio, 0.23 (+/- 0.02). After single oral doses, t 1/2 beta (3.8 +/- 0.2 h) tended to be smaller than after the IV dose, and actual systemic availability (0.60 +/- 0.07) was less than that based on the predicted extraction ratio. During multiple oral dosage (80 mg every 12 h), observed steady state serum levels (47 +/- 5 ng/ml) tended to be less than those predicted based on the single oral dose (61 +/- 5 ng/ml), thus providing no evidence for reduced propranolol clearance at steady-state. Echocardiographic measurements of left ventricular performance (posterior wall velocity, diastolic dimensions) made during the single-dose oral study indicated significant impairment of function; impairment was maximal at 3 h post-dosage, and corresponded to the time of the peak serum propranolol concentration (341 ng/ml).

Administration, Oral↗
PubMed1981

Intravenous quinidine in congestive cardiomyopathy.

Eight male patients with compensated congestive cardiomyopathy received single 300-mg doses of intravenous quinidine by 15-min infusion. Left ventricular (LV) performance was evaluated by echocardiography at multiple points in time during the next 24 h. Quinidine kinetics and protein binding were determined from multiple serum samples drawn for up to 36 h after dosage. LV function was not impaired. Instead, quinidine transiently increased ejection fraction (mean: +39%) and rate of circumferential shortening (mean: +46%). Endsystolic and end-diastolic LV internal diameter likewise were decreased (means: -13% and -7%). Blood pressure and ventricular rate were not significantly altered. Compared to 8 healthy controls matched for age, sex, and weight, quinidine volume of distribution among patients was smaller (means: 2.27 vs 1.90 l/kg), as was total quinidine clearance (3.49 vs 2.84 ml/min/kg); however, differences were not statistically significant. Well-controlled, slow intravenous infusion of quinidine does not impair LV performance and is safe for patients with compensated congestive cardiomyopathy. However, such patients may have reduced quinidine clearance and hence require lower doses than expected based on age and weight.

Adult↗
PubMed1981

[Computer tomographic diagnosis of cardiac, pericardial and paracardial space occupying lesions].

By means of the pathological findings of 63 patients diagnosed by CT of the heart the radiodiagnostic signs of myocardial, pericardial and paracardial space occupying processes are demonstrated with emphasis on CT of the heart. In addition the electrocardiographic findings of 46 patients are compared with the CT-findings. Whereas there are no essential differences between the results of the two methods diagnosing intramural and greater intracavitary tumors, CT is to prefer at the differential diagnosis of pericardial and paracardial tumors. CT is superior to echocardiography diagnosing small intracavitary thrombi.

Coronary Disease↗
PubMed1980

Effects of verapamil on P-R-intervals in relation to verapamil plasma levels following single I.V. and oral administration and during chronic treatment.

A close relationship between verapamil plasma concentration and effect on P-R interval could be established both after single i.v. and oral administration and during chronic oral treatment. After i.v. administration a linear relationship between verapamil plasma concentration and delta P-R (y=x (0.74) + 1.8) with a small between subject variation in the slope of the regression (%coefficient of variation 18.7, range 0.71-1.10) was observed. The slope of the oral plasma concentration response regression (y=x (0.33)-3.0) was statistically significantly (p less than 0.05) less than the slope of the i.v. plasma level response regression. Interindividual variation in the slope was most pronounced (range 0.13 to 0.47). On average two to three times higher verapamil plasma levels were required after oral administration in order to produce the same increase in delta PR as after intravenous administration. The most plausible explanation for the different slopes of the plasma level response regression seems to be stereo-selective presystemic elimination. Since after oral administration the plasma level response curve is less steep than after i.v. administration this indicates that the more active l-isomer is preferentially metabolized during hepatic first-pass metabolism.

Administration, Oral↗
PubMed1980

[Cardiac effects of isoproterenol in the complex echocardiographic evaluation (author's transl)].

The cardiac response to isoproterenol was examined in 10 normal subjects by echocardiography. The complete qualitative and computer-assisted quantitative analysis of one-dimensional recordings of the left ventricle is combined with two-dimensional echograms. The results - including the well-known facts that cardiac output and the velocity of contraction are increased while the end-diastolic dimensions are partly decreased - indicate that the stroke volume is not significantly diminished in the supine position. In two cases it is even enlarged. Moreover, a "pseudo-Sam" and the changes of the systolic time intervals demonstrate the strong positive inotropic effect of the drug. The amplitude of the descent of the base movement is also enlarged. The velocity of relaxation is not as increased as the velocity of contraction in that part of the posterior wall which is hit by the echobeam. There is a remarkable dissociation between the Ecg and the actual cardiac movements. E.g., with isoproterenol the mitral valve opens during the ascending T-wave, while normally relaxation only starts after complete electrical repolarisation. The shortening fractions of the phases of the cardiac cycle induced by the drug as compared to the control state are determined. It is shown that shortening of the whole cardiac cycle causes the systolic phase to shorten to a nearly adequate ratio. The slow filling phase mostly shortens to the smallest while the rapid filling phase always shortens to the greatest ratio. We discuss all echocardiographic parameters that are used for this study and we demonstrate some limitations to the interpretation of time-dimension curves derived from M-mode echocardiograms. These are especially evident after a strong beta-sympathomimetic stimulation, because after the injection of isoproterenol the appearance of the septal echo-lines changes from one subjects to the other in a striking way.

Adult↗
PubMed1979

[Demonstration of left-ventricular contraction anomalies with the two-dimensional sector-scanner (author's transl)].

Echocardiographic findings were compared with those obtained by cardiac catheterisation in 134 patients. Echocardiography was performed in the standard plane of the long and short axes, as well as from the cardiac apex. After dividing the left ventricle into several segments wall movement was measured in them and compared with those obtained by ventricular angiography in the right and left anterior oblique positions. It was found that in patients with left-ventricular aneurysm, proven by left ventricular angio, there was complete conformity with regard to localisation and extent of the aneurysm between the two methods of investigation. In this group 79% of the demonstrated segments could be adequately assessed and, in 91%, agreed with the radiological findings. In the group of patients without aneurysm only 68% of the segments could be adequately assessed, and 77% correctly assessed wall movement when compared with the laevocardiogram. Tracing recorded from the cardiac apex gave especially good results in demonstrating the ventricle and its segments.

Adult↗
PubMed1979

[Computer-cardio-tomography in idiopathic hypertrophic subvalvular aortic stenosis--a new contribution to non-invasive diagnosis (author's transl)].

The use of computer tomography as a non-invasive procedure in the diagnosis of idiopathic hypertrophic subvalvular aortic stenosis is described. Seven patients were investigated in whom the diagnosis had been confirmed by echocardiography and laevocardiography with pressure measurements. Details of the method are discussed and computer tomography and echocardiography are compared. The features of greatest differential diagnostic importance relating to asymmetrical septum hypertrophy are discussed.

Cardiomegaly↗