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Biomedical subjects

H Kreuzer

Publications and source records attributed to H Kreuzer.

At least 235 records · Page 13Linked to original sources
PubMed1986

[Valve replacement in patients over 70 years of age].

The extension of cardiac diagnostics by invasive and non invasive, imaging procedures results in an extension of indication for cardiac surgery of patients over 70 years. From August 1977 to July 1985 a total of 212 patients over 70 years were operated upon with extracorporeal circulation for different heart diseases. The mean age was 73.2 years (from 70 to 84 years). In almost 57% (121) of the patients with coronary heart disease (CHD) an aortocoronary venous-bypass (ACVB) was performed, with a mean of 3.3 grafts (ranged from 1 to 5). In 84 patients an isolated or combined heart valve replacement was carried out: Aortic valve replacement (AVR) in 51, mitral valve replacement (MVR) in 11, AVR and MVR in 4, AVR and ACVB in 16 and AVR and aortic ascendens replacement in 2 patients. The overall mortality was 8.5%, with isolated AVR 7.8%, with isolated ACVB it was at the lowest with 5.2%. Postoperative complications could be observed in 48% of patients: low output syndrome (LOS) in 4, arrhythmia in 11, respiratory insufficiency (5%) or stroke in 2, mental confusion in 5. The long-term results after heart valve operation in patients over 70 years emphasize the indication for surgery, despite the higher rate of postoperative complications. The hospital mortality does not differ from that of younger patients. Especially with extreme valvular aortic stenosis after acute AVR one can expect a quick improvement of the cardiac situation after unloading of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Antithrombotic efficacy and its time course after application of naftidrofuryl in vivo.

The antithrombotic efficacy of naftidrofuryl (Naf) was assessed with the following method: an endothelial cell damage is induced in arteriolar vessels of the hamster cheek pouch by intravascular excitation of fluorescein-isothiocyanate-dextran. On these damaged cells, platelets adhere and a stable thrombus grows. This process progressively obstructs the vessel's aperture and hence reduces blood flow. Blood cell velocity may thus be used to quantitate thrombus growth. Thrombus growth is assessed before and repetitively after parenteral application of 1, 5 and 20 mg/kg Naf. Efficacy is compared with 10 and 100 mg/kg acetylsalicylic acid. Naf shows a significant antithrombotic property, beginning with a dosage of 1 mg/kg which further increases relative to the dosage, and the stability of thrombi decreased. The antithrombotic effectiveness of Naf increases continuously during 120 min after application. Vessel diameter and cell velocity were the same in compared groups thus excluding an influence of the vasodilatory property of Naf on thrombus growth. Sixty min after application, 5 mg/kg Naf was as effective as 10 mg/kg acetylsalicylic acid.

Animals↗
PubMed1985

[Diuretic monotherapy in heart failure. Comparison of piretanide and hydrochlorothiazide-triamterene].

The effects of piretanide and a hydrochlorothiazide (HCT)-triamterene combination were compared in an open, controlled, randomised study on two groups of 15 patients, aged 42-74 years, with congestive heart failure (NYHA II-III). Weight loss was significant in both groups (P less than 0.05). At the end of the 14 day investigation ten patients from the piretanide group but only four patients from the HCT-triamterene group were fully recompensated. The left ventricular end-systolic and end-diastolic diameters were significantly less under piretanide (P less than 0.05 and P less than 0.01, respectively) than under HCT-triamterene. The shortening fraction and the circumferential velocity of shortening under piretanide increased by 25% over the initial value (P less than 0.001) whereas HCT-triamterene produced no change. A small but statistically significant (P less than 0.05) fall in serum potassium as well as a rise in urinary potassium, sodium and chloride concentration occurred with piretanide.

Adult↗
PubMed1985

[Experiences with telemetry-supported pacemaker controls in patients with VVI pacemakers].

Investigations on telemetry-supported pacemaker control were carried out in 55 patients with the VVI-pacemaker Quantum (Intermedics). The investigations were done at least once during the 6-24 month period after implantation. The telemetry function was utilised for pacemaker programming, for clarifying pacemaker defects and for characterising the type of pacemaker electrode used. It could be shown that the Osypka spiral electrode VY (Dr. Osypka) had a lower impedance, and greater pulse width and charge threshold in comparison with the two other electrodes used (Encor, Cordis; Polyflex, Intermedics). In 38 of the 55 patients (69%) a pulse amplitude of 2.7 V could be chosen, whereas an amplitude of 5.4 V was programmed in the rest. Pacemaker sensing threshold was set to values between 2.4 and 3.0 mV. Pacemaker problems appeared in three patients; in one patient due to programming too economically and in the other two due to pacemaker defects.

Adult↗
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

A new technique for measuring oxygen saturations of hemoglobin and myoglobin and its application in open heart surgery.

Light reflected from the human heart surface was used to determine mixed hemoglobin and myoglobin oxygen saturations (O2SAT) in the cardiac tissue. The measurements were performed in 8 patients with coronary heart disease including stenosis of left anterior descending coronary artery (LAD) who underwent aorto-coronary bypass surgery. At the end of the operation the O2SAT was measured in the supply area of the LAD either with patent or occluded coronary bypass. In 13 experiments occlusion of the bypass resulted in a decrease of O2SAT from 74 +/- 16% to 61 +/- 24% (p less than 0.02). A new technique is introduced and its limitations are discussed. Preliminary results of application in coronary bypass surgery demonstrate an increase in tissue oxygenation following myocardial revascularization.

Coronary Artery Bypass↗
PubMed1985

Spontaneous hemodynamic improvement or stabilization and associated biopsy findings in patients with congestive cardiomyopathy.

The hemodynamic courses of 56 patients with congestive cardiomyopathy (CCM) were investigated. Fourteen patients died within 24 months after diagnosis. The hemodynamic courses of the remaining 42 patients were investigated in subsequent examinations by determination of left ventricular ejection fraction (LVEF), mean pulmonary arterial pressure at maximal workload, and peak systolic pressure/end-systolic volume index. During the study interval of 32.2 +/- 20.0 months the conditions of 20 patients (48%) deteriorated, according to their hemodynamic status, and at least five of these died of terminal heart failure. Surprisingly, the conditions of 22 patients (52%) improved or stabilized. One of these died of leukemia. Seven patients in the latter group with initial LVEFs of 0.30 or less experienced an average increase from 0.22 to 0.51. Retrospectively consideration of age, alcohol intake, exercise capacity, and hemodynamic status were not helpful in predicting the course of the disease. In 38 patients endomyocardial biopsy samples could be obtained at the time of diagnosis. Reduced myofibril volume fraction (less than 60%) had prognostic significance for both hemodynamic deterioration and death (sensitivity 23/24 = 96%), while 14 of 15 patients whose conditions improved or stabilized had a myofibril volume fraction of 60% or more (specificity 14/15 or 93%, p less than .002). A relationship between hemodynamic status and the myofibril volume fraction could not be found. Individual patients with CCM differ significantly with respect to course of the disease. A distinct separation of the patients by means of morphologic criteria is possible. This makes it more likely that the pathogenesis of the disease is not unique.

Adolescent↗
PubMed1985

[Ventricular arrhythmias in left coronary main branch stensosis].

It is far from clear whether ischemia plays a major role in the genesis of ventricular arrhythmias in patients with chronic coronary heart disease. Since patients with left main coronary artery disease suffer from transient or even chronic ischemia including significant parts of the left ventricular muscle mass, it seems worthwhile looking for spontaneous arrhythmias in this particular clinical setting. Therefore we studied 56 patients (53 males, 3 females) with documented left main coronary artery disease (20 patients (35%) with 30-50% luminal narrowing, 36 patients (65%) with greater than or equal to 50% stenosis) using 24-hour continuous ambulatory electrocardiography. Only 5 patients were without ectopic activity. 32 patients (57%) showed ventricular extrasystoles (VES) of uniform or multiform configuration according to Lown class I-III, whereas 19 patients (34%) demonstrated consecutive VES equivalent to Lown class IV. In ten of the latter short runs of ventricular tachycardia (Lown IVb) were the maximal finding. No relation could be assessed between spontaneous ventricular arrhythmias and the extent of coronary artery disease, neither with regard to the degree of narrowing of the left main coronary artery, nor with regard to the additional coronary involvement in terms of 1-, 2- or 3-vessel disease. In contrast, there was a significant relationship between impaired left ventricular function in terms of biplane left ventricular ejection fraction and frequent VES (chi 2 = 11.272; p less than 0.01) as well as complex, namely consecutive forms (chi 2 = 9.548; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Electrophysiologic findings in patients with Kearns-Sayre syndrome--report on 2 cases].

The Kearns-Sayre syndrome is identified by the triad of progressive external ophthalmoplegia, atypical pigmentary retinopathy, and conduction disturbances. In addition, clinical manifestations may include mental retardation, sensorineural deafness, cerebellar ataxia, and facial and peripheral muscle weakness. Morphologic alterations in skeletal muscle may be characterized by ragged-red fibers. Two patients with Kearns-Sayre syndrome underwent electrophysiological examination. The first patient had a first and second degree AV block (Mobitz type II), right bundle branch block, and left axis deviation. The His-bundle electrogram showed a prolonged HV interval as a hint at an intraventricular conduction delay. The signal-averaging technique and endocardial mapping revealed ventricular after-depolarizations. The second patient had an unsuspicious ECG, recurrent atrial tachycardias, normal atrial and ventricular conduction, and after-depolarizations in endocardial mapping. Two months later he showed a second degree AV block combined with clinical symptoms. Pacemakers were implanted in both patients. Beside disturbances of the conduction system in both patients signs of electrical instability of the myocardium were found. In this way the Kearns-Sayre syndrome may be seen as a form of cardiomyopathy.

Adult↗
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↗
PubMed1985

[Noninvasive determination of stroke volume with spectral Doppler echocardiography].

To assess the determination of volume flow by Doppler echokardiography 15 patients were studied twice in intervals of 2 to 6 hours. Cardiac output was determined simultaneously by thermodilution and by Doppler echocardiography. In three patients (20%) no Doppler signal could be recorded. In the 24 successful determinations a correlation of r = 0.93 was found between the two techniques. Mean deviation was 0.57 l/min (0.15-1.16), 9% (1-20%) respectively. With serial measurements the correlation for changes in cardiac output was 0.94. Mean deviation was found to be 0.47 l/min (0.12-1.16), or 75% (9-395%). Thus, gross estimation of cardiac output by Doppler echocardiography seems possible. However, it cannot be judged as of yet whether a more than semiquantitative estimation of individual cardiac output changes is possible nor whether further information can be obtained besides that which is clinically available.

Blood Flow Velocity↗
PubMed1984

[Determination of left atrial size. Comparison between echocardiographic and radiological determination].

The size of the left atrium was determined echocardiographically and radiologically in 66 patients with mitral valve disease, grade I-IV (New York Heart Association classification). Angiocardiography served as the reference. The echocardiographic determination was both by M-mode and two-dimensional, the radiological one was from the postero-anterior films (after Higgins), as well as from the lateral pictures. There was good agreement between the two echocardiographic methods and a good correlation of the two with cine-angiographic measurements (r = 0.82-0.99; P less than 0.001). But there was a poorer, although still statistically significant correlation of the radiologically determined atrial size with the echocardiographic and angiocardiographic measurements (r = 0.47-0.56; P less than 0.001). Thus M-mode and two-dimensional echocardiography is the more sensitive method for determining the size of the left atrium.

Adult↗
PubMed1984

[Formation of multiple round foci in the lung during amiodarone therapy].

During treatment with the antiarrhythmic agent amiodarone pulmonary infiltrates may be observed occasionally. Such a side-effect was seen in a 67-year-old patient after several months of amiodarone therapy (200 mg/d during 5 days of the week). After withdrawal of the drug the infiltrates regressed over a period of two months. No other causes for the pulmonary opacities could be established. So far, 13 patients with pulmonary changes during amiodarone treatment have been reported in the literature.

Aged↗
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

The effect of two different diltiazem treatments on infarct size in ischemic, reperfused porcine hearts.

The effect of diltiazem on the development of infarcts was investigated in porcine hearts. The left anterior descending coronary artery was occluded in each of 32 anesthetized pigs for 75 min and was reperfused for 4 hr. Diltiazem (15 micrograms/kg X min) was infused in 11 pigs for 30 min before occlusion (therapy A) and in another eight pigs before reperfusion (therapy B). Eleven pigs served as controls. Tissue concentrations of adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide (NAD) were determined in transmural needle biopsy samples taken from the ischemic apex after 70 min of ischemia. The infarct size, expressed as the ratio of the infarcted tissue over the area at risk of necrosis multiplied by 100, amounted to 79 +/- 20% in the control group. Although there was no significant difference between hemodynamics in the control and the treated groups, pretreatment with diltiazem significantly reduced infarct size (53 +/- 26%; p = .025). Reduction of infarct size by therapy B did not reach the required level of significance (66 +/- 33%). The ischemic loss of ATP and NAD was significantly lower in the pretreated group, which further indicates that the beneficial effect of diltiazem was exerted primarily during ischemia and not during reperfusion.

Adenosine Triphosphate↗