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Biomedical subjects

H J Duck

Publications and source records attributed to H J Duck.

At least 19 recordsLinked to original sources
PubMed1992

[Densitometry determination of coronary flow rates using digital subtraction angiography (DSA). Methods, multiple examinations and interobserver comparison].

In invasive diagnostics of coronary heart disease (CHD), three each DSA examinations of the left coronary artery were performed at 2-minute intervals in ten patients subsequent to conventional examination by means of a left-side cardiac catheter and coronary angiography. While placing the patient in left anterior oblique (60 degrees) position, 6 ml each of ionic contrast medium were injected mechanically with a flow of 4 ml/sec at a pacemaker-induced heart rate of 100/min. Examinations were performed according to a standard mode and were evaluated via the image analysing computer APU of the Philips DVI-DSA system. The purpose of this approach was to analyse the examination conditions and a new improved evaluation algorithm in respect of stability, feasibility and sensitivity. 17 series were evaluated by two examiners who were independent of each other. The interobserver differences obtained were between 5% at the time of maximum density (Tmax) and 25% with exponential downward slope of the curve (lambda), with reference to the median value in each case. Scatter of the individual examinations around the median value of all the three DSA runs is 11 to 17% with the exception of lambda. A significant rise can be proven in the RCX region for the curve slope rise parameters "slope" and "RFL2". We interpret this as a genuine 1.2 to 1.3 fold regional flow increase due to the residual effect of the contrast medium. At the same time, this can be interpreted as an indicator for the good sensitivity of the method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Heterotopic bone in hip arthroplasties. Cemented versus noncemented.

Sixty-six hip arthroplasties in 55 patients were reviewed to specifically study cemented versus noncemented procedures, as related to heterotopic bone formation (HBF). Other factors considered included the type of arthroplasty, surgical approaches, preoperative and postoperative medicines, preoperative predisposing diagnoses, range of motion, and pain. The overall percentage of heterotopic ossification was 64%. There was no significant difference between cemented (67%) and noncemented (55%) procedures. Except for an increased percentage (80%) of ossification after a trochanteric osteotomy, there were no significant differences between the three reviewed surgical approaches. Male osteoarthritics had the highest overall HBF. Eighty percent of patients who previously had developed HBF also did so with a contralateral hip surgery. Surprisingly, all patients with gout (100%) developed HBF. Acetylsalicylic acid used prophylactically for anticoagulation had no significant effect. Resurfacing arthroplasty procedures accounted for half of the severe grades of HBF. A decreased range of motion occurred with more severe grades of HBF.

Age Factors↗
PubMed1990

[A densitometric method for the assessment of myocardial perfusion using digital subtraction angiography].

The aim of the method presented is the quantitative description of the perfusion of the myocardium. In the framework of the invasive diagnostics of the coronary heart disease with catheterization of the left heart, ventriculography and coronarography in Seldinger's technique in 50 patients (35 of them well to be evaluated) subsequently DSA-investigations of the left coronary artery (LCA) were performed by means of the DVI-2 CV system (Philips) and densitometrically evaluated with the help of the analytic processing unit (APU). In injection by hand of 4 and 6 ml, respectively, visotrast 370 in each case 10-15 DSA-pictures in LAO 60 degrees-projection were possible. For a differentiated evaluation the total myocardium was subdivided into 12 partial areas. The densitometric analysis consisted in the calculation of time-density curves over all areas and their description by suitable parameters: density maximum (DMAX) and its moment TMAX, elevation of the curve SLOPE at 50% of DMAX, the elevation time AZEIT as well as measure for the exponential decrease of the curve after the maximum LAMBDA. For special questioning the parameters of the 12 areas were concentrated according to the main supply areas of the anterior interventricular branch (RIVA), the circumflex branch (RCX) and the apex of the heart, respectively. In the interobserver comparison the statistical analysis of the results showed deviations lower than 10% (except LAMBDA). Significant correlations were found between the body-weight and the applied quantity of contrast remedies, respectively, and the parameters DMAX and AZEIT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Postoperative supraventricular arrhythmias in atrial septal defects].

Before operation as well as over a mean postoperative period of 8.9 years 222 adults with atrial septal defects underwent a follow-up examination concerning frequency and clinical significance of supraventricular dysrhythmias. Thereby disturbances of the formation of stimuli were found before the operative procedure in 60 patients and after the correction in 115 patients. Disturbances of the sinoatrial and atrioventricular conduction were registered preoperatively in 53 cases and postoperatively in 81 cases. Within these statistically significant increases in particular the significant forms of dysrhythmia elevated after the atrial septal defect closure. Thus the tachycardiac atrial dysrhythmias increased from 7 to 28%, complex arrhythmias even from 2 to 16%. Of dysrhythmias to be taken seriously patients with IAVC and supraventricular defect are significantly more frequently affected than those with interatrial septal defects. Size of the defect, shunt volume and pressure of the pulmonary artery did not show any connections with the frequency of dysrhythmia. On the other hand, when accompanying cardiac anomalies, symptoms of a manifest heart insufficiency were present and at an operation age over 40 years arrhythmias were proved more frequently. The complaints of the patients did not correlate with the endangering, but are imprinted by the haemodynamics and its postoperative normalization. By the established profile of complaints and a decrease of frequency from 76% pre- to only 40% postoperative the patient with atrial septal defect cannot estimate his individual risk and needs an adapted long-term concept for his cardiological care.

Adolescent↗
PubMed1990

[Venous digital subtraction angiography of the left ventricle in comparison with conventional angiography].

In 42 patients with coronary heart disease within a left heart catheterization by means of coronarography and conventional angiocardiography in each case before and after GTN digital subtraction angiographies of the left ventricle were performed with central venous injection of 20 ml visotrast with a flow of 16-18 ml/s. A DVI2-CV system of the firm Philips served as investigation device. In general between the angiocardiography and the digital subtraction angiographies the following results were obtained for EF 0.81, EDV 0.71, and ESV 0.88. When evaluating only the finally examined 22 patients the correlations improve for all parameters (EF: 0.89, EDV: 0.82, ESV: 0.90). Furthermore is was shown that the volumes are underestimated by 8-10%. The quantification of the regional movement of the wall according to the radial axis method did not results in any significant differences between the digital subtraction angiographies and the angiocardiography. The effects of GTN on the global and regional functional parameters appear somewhat more distinct in the digital subtraction angiographies than in the angiocardiography and are partly significant only in the first one. The influence of the experience of the investigator, the cardial state of the patient and other influential factors on the quality of the digital subtraction angiocardiographies are described and discussed. Therefore we regard the digital subtraction angiography as method of choice in indications to right heart catheterization without coronary angiography.

Adult↗
PubMed1989

[In vivo effects of high density lipoprotein rich serum fractions (HDLF) in the human. 2. Effect of repeated HDLF infusions on atherogenic risk factors and arteriosclerotic vascular changes in patients with and without hyperlipoproteinemia].

10 patients with hyperlipoproteinaemia and 4 normolipaemic smokers with angiographically proved arteriosclerosis of different degrees of severity were infused in 2-week intervals 100 ml HDL-rich Cohn-IV-1 fractions each. After the infusion for 5 days essential phospholipids were injected and a permanent medication with cholestyramin and a choleretic drug were prescribed. In the patients with HLP increases of concentration, decreases of concentration, constancy of the plasma lipids and apoproteins independent of the phaenotype of the HLP as well as an improvement of the state of the antioxidant state were observed. In 6 of 10 patients in reproducible vascular areas regressions of athero- und arteriosclerotic findings could be made evident. Progressions were not observed also in extremely changed arteries in contrast to the normolipaemic smokers and the patients of the control group.

Arteriosclerosis↗
PubMed1989

[Hyperthyroidism and its relation to heart function].

The influence of hyperthyreosis on the cardiac function was investigated by means of non-invasive methods (radiocardiography, echocardiography, Tc-99m- und Tl-201-scintigraphy of the myocardium) and invasive methods (coronary angiography). Independent of age an increase of the frequency was always existing, a significant increase of the filling of the ventricle, of SI and HI was shown only by younger patients. With the help of the echocardiography local and global disturbances of kinetics, by means of the Tl-201-scintigraphy of the myocardium disturbances of the myocardial perfusion could be proved. For the circulating plasma catecholamines noradrenalin, adrenalin and dopamine values were established lying in the lower region of the normal. The effects of an increase of the thyroid hormone on the number and/or sensitivity of the membrane-bound beta-adrenoceptors of the heart as well as the independent of its effect of the SDH on the obtaining of myocardial energy are discussed.

Adolescent↗
PubMed1988

[Assessment of causality in fatal incidents in relation to coronary angiography].

Among 2,353 coronary angiographies (from 1.10.1984 until 30.9.1987) four lethal cases were seen. In two cases there was evidence for a causal relationship between coronary angiography and the lethal outcome (0.9%). Possible mechanisms of death are discussed. The clinical course and the time sequence between coronary angiography and the death are considered to be important criteria of a causal relationship.

Aged↗
PubMed1988

[Determination of global left ventricular functional parameters with intraventricular digital subtraction angiography in coronary disease].

Left heart catheterisation, coronarography and conventional angiocardiography of the left ventricle (ACG) [30 degrees right anterior oblique; 45 ml contrast medium (Visotrast) with a flow of 12 ml per sec.] was performed in 86 patients with coronary heart disease. Additionally intraventricular digital subtraction angiography (DSA) was performed, using a Philips-device (DVI 2 CV). For DSA 15 ml contrast medium (Visotrast) was injected with a flow of 8 ml per sec. 73 examinations were selected for the study. The aim of the study was to compare the usefulness and applicability of ACG und DSA for ventriculography. There were no significant differences between enddiastolic (EDV) and endsystolic (ESV) volumes as well as ejection fractions (EF) determined by ACG and DSA. Results of the analysis of correlation were rEDV = 0.85;rESV = 0.93;rEF = 0.80. The increase of the end-diastolic pressure after ACG was determined with 7 Torr (mean), after DSA with less than 2 Torr (mean). According to these results we would prefer intraventricular DSA to conventional ACG, provided the technical equipment is available. This is concluded despite the fact that in single cases considerable differences were found between the volumes estimated by ACG and those determined by DSA. These differences were analysed in detail. The main advantages of the DSA are the by far smaller inconvenience for the patients, the rare occurrence of provoked extrasystoles and the fast and easy analysis of the ventriculographies by means of the implemented image processing programmes.

Cardiac Output↗
PubMed1988

[Initial experiences with the effect of chronic intermittent electromyostimulation in patients with hyperlipoproteinemias and arterial circulatory disorders].

Metabolic and clinical effects of an original electromyostimulation are explained which induces muscle contractions by changes of the field intensity in the region of microseconds in forms of delivered impulse groups. On account of the good local compatibility due to optimal irritation parameters the muscle stimulator was suitable for a long-term application. Examinations on 23 patients with hyperlipoproteinaemia and mixed HLP (n = 15) and primary hypercholesterolaemia (n = 8) after a 2 times 2 hours/day mutual stimulation of the femoral musculature in a frequency of 2 s-1 lasting four weeks yielded a significant decrease of the triglyceride and cholesterol concentrations as well as an increase of the HDL-cholesterol in mixed HLP-forms. Examinations not yet finished refer to an increase of the extrahepatic activity of the postheparin-lipoprotein lipase and to the concentration of the HDL2-cholesterol. An influence of the hypercholesterolaemia IIa could not be made evident. An electrostimulation performed for 3 months in 8 patients with obliterating arteriosclerosis resulted in a more sufficient collateral blood supply of the legs. The long-term use of the device was unobjectionable also under ambulatory conditions. On the basis of additionally gathered experiences further indications of an electrostimulation were cited. Possible variations of the electrostimulation irritation parameters might make accessible further fields for the preventive and curative medicine.

Adult↗
PubMed1987

[Coronary surgery in females].

In the last three years, of a total of 617 patients undergoing surgery for ischemic heart disease, 53 were women (8.6%). With one exception, all were in or shortly before the menopause. As compared with men, the women were found to have a preponderance of risk factors. The most unfavorable combination, that of hypertension and hypercholesterolemia, was present in one-third of the patients. Hospital mortality for isolated revascularization was higher in women at 4.9% than in men at 1.5%. The one-year survival rates, however, of 94.4% and 95%, respectively, did not differ between the two sexes. In women, the number of grafts per patient was 2.1 as compared with 2.9 in men. Complete revascularization was achieved less frequently in women than in men; similarly graft patency rate at one year of 66% in women was less than the 84% observed in men. The more marked coronary sclerosis as well as morphologic characteristics of coronary arteries in women construe a special challenge to the surgeon and prerequisite a high degree of technical skill.

Adult↗
PubMed1985

[Behavior of late ventricular potentials in acute experimental myocardial ischemia].

Locally retarded depolarizations of the ischaemic myocardium are regarded as frequent trigger mechanisms of dangerous ventricular arrhythmias. Up to now, however, there are scarcely systematic investigations concerning their concrete developmental conditions in man, since late potentials can be made evident only by means of expensive invasive methods or signal mediation techniques. Therefore, an animal model should be built, which is suitable for the control of new therapy conceptions with antiarrhythmic drugs. The investigations were performed on 22 pigs in whom under insufflation anaesthesia altogether 10 pressure, flow and contractility parameters as well as 6 epicardial ECG signals were continuously recorded. The episodes of ischaemia were caused by LAD occlusions of different duration and intensity. Typical late potentials could be registered in 5 animals who all had survived complete interruptions of the coronary blood flow of longer than 10 min. The mean duration of the late potentials was 20 +/- 9.2 ms, their amplitudes reached from 150 to 600 microV. Also with regard to time and cycle constancy, the delay of the late Q-potential and the morphology they corresponded to the homogeneous phenomenon, known from man. They always could be derived only from electrodes outside the immediate zone of ischaemia. Neither partial occlusions nor complete interruption of the coronary blood flow in intervals shorter than 10 minutes led to the development of a late potential. The animal model used altogether appears very suitable to investigate the medicamentous influencibility of arrhythmogenic areas of the myocardium under direct control of the dynamic behaviour of ventricular late potentials.

Acute Disease↗
PubMed1979

[Abnormal myocardial blood flow distribution with a normal coronarogram in angina pectoris and after myocardial infarction].

It is reported on the selective coronary perfusion scintigraphy in 47 patients with angina pectoris and condition after myocardial infarction, which was performed simultaneously with the coronary angiography. For the paper were interesting the cases with normal coronarogram, but pathological perfusion scintigram. 3 of 25 patients with condition of infarction showed coronarographically inconspicuous vessels. In all cases the perfusion scintigram shows disturbances of regional perfusion, which corresponded with the electrocardiographic localisation of the infarction. In 3 of 22 patients with angina pectoris with normal coronarogram in the scintigram regional changes of the terminal vascular system were established. In 2 cases simultaneously a disturbance of rhythm and stimulus conduction was present, which showed a conspicuous correlation to the perfusion lesions in the septum. In the small intramural vessels haemodynamically effective changes take place which are below the coronarogram. Therefore, the only coronarography is not enough to confirm or to refuse a genuine angina pectoris or an infarction. The selecitve coronary perfusion scintigraphy gives the possibility to prove disturbances of the distribution of regional blood supply without a greater additional load of the patient as to coronary angiography. However, it cannot give evidence on the genesis of disturbances in the terminal vascular system in the normal coronarogram

Adult↗
PubMed1979

[Quantitative measurement of arterial flow by means of directional Doppler technic in hemodynamic animal experiments].

The usability of the continuous ultrasonic Doppler-method for the measurement of the blood flow in the haemodynamic animal experiment was tested. For this purpose measurements at the ascending aorta and the commune carotid artery were performed on different current conditions and compared with the electromagnetically registered blood flow. The causes for the non-conformity are discussed.

Animals↗
PubMed1979

[Clinico-diagnostic criteria for the evaluation of social aspects in acquired heart valve diseases].

In spite of the retrogression of the acute rheumatic fever the acquired valvular defects still play an essential role for the morbidity and mortality above all for the younger and middle decenniums of life. In the preliminary diagnostics it is the task of the family doctor to diagnose the valvular defect, to differentiate it from non-organic findings and to estimate its degree of severity. The diagnosis of a carditis renders special difficulties, particularly in its chronic recurrent form. Certain situations of life do not demand only an actual analysis of the findings, but also an individual prognostic estimation. For the choice of profession, the ability for military service and driving a car general references and regularities must be taken into consideration. The indication to operation of the valvular defect is generally given in degree of severity and with restriction also in stage IV. A mitral stenosis is operated already in stage II, when stronger complaints and haemodynamic changes are present. Patients with degree of severity III and IV should avoid a pregnancy, in stage I and II under common control by the internist and obstetrician the pregnant patient may not have any scruples to carry to full term.

Abortion, Therapeutic↗