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Biomedical subjects

J H Müller

Publications and source records attributed to J H Müller.

At least 19 recordsLinked to original sources
PubMed2001

Bloch oscillations and mean-field effects of Bose-Einstein condensates in 1D optical lattices.

We have loaded Bose-Einstein condensates into one-dimensional, off-resonant optical lattices and accelerated them by chirping the frequency difference between the two lattice beams. For small values of the lattice well depth, Bloch oscillations were observed. Reducing the potential depth further, Landau-Zener tunneling out of the lowest lattice band, leading to a breakdown of the oscillations, was also studied and used as a probe for the effective potential resulting from mean-field interactions as predicted by Choi and Niu [Phys. Rev. Lett. 82, 2022 (1999)]. The effective potential was measured for various condensate densities and trap geometries, yielding good qualitative agreement with theoretical calculations.

Journal Article↗
PubMed2001

Bridging-to-recovery.

BACKGROUND: Patients with end-stage heart failure placed on a cardiac assist device show at least some degree of improvement of cardiac function. In a subgroup of selected patients, some hearts recovered considerable function. In these patients the device was removed and cardiac transplantation was no longer necessary. We report our long-term experience with these weaned patients. METHODS: As of today, 512 cardiac assist devices of various types (Berlin Heart, Berlin, Germany; Novacor, World Heart, Ottawa, Ontario, Canada; TCI, ThermoCardio Systems, Inc, Woburn, MA; DeBakey, Micromed Technology Inc, Houston, TX) were implanted in patients with end-stage heart failure in our institution. Of these, 95 patients belonged to a subgroup of patients with nonischemic, idiopathic, dilated cardiomyopathy who were implanted with a left ventricular support system (Novacor 84, TCI 10, Berlin Heart 1) between 1994 and 2000. All were routinely examined by echocardiography for improvement of cardiac function. The left ventricular diameter in diastole (LVIDd) and left ventricular ejection fraction (LVEF) served as the main parameters to assess changes in cardiac performance. Under the conditions of a running device, an LVIDd below 60 mm and an LVEF above 40% were the criteria to do further echocardiographic studies when the pump was turned off for up to 20 minutes. RESULTS: Twenty-eight patients (26 men, 2 women; ages 18 to 64 yrs; history of heart failure, 1 to 17 yrs) fulfilled the criteria of improved cardiac performance and were weaned from the device. Since then, 16 patients have continued "normal" heart function with follow-up times ranging from 1 month to 5.5 years (group B). Three patients died of noncardiac causes (group C). Eight patients were transplanted from 1 to 17 months later and one died on the waiting list (group A). Statistically significant differences between groups A and B were calculated for the duration of heart failure (9 versus 2 years, p = 0.0002). Differences in LVIDd before removal of the device (57 versus 51 mm, p = 0.0420), LVEF after 2 months of unloading (30 versus 49%, p = 0.0300), and LVEF preexplantation (43 versus 52%, p = 0.0001) were significant. Overall, 17% of the cohort of 95 patients were weaned successfully. CONCLUSIONS: Weaning from cardiac assist devices is feasible for selected patients; it saves donor hearts and is preferred to cardiac transplantation. However, as of today no reliable parameter predicts outcome after weaning and none determines the possibility of device removal before implantation in advance.

Adolescent↗
PubMed2000

Midterm follow-up of patients who underwent removal of a left ventricular assist device after cardiac recovery from end-stage dilated cardiomyopathy.

OBJECTIVE: Cardiac recovery in end-stage idiopathic dilated cardiomyopathy recently occurred after temporary support with a left ventricular assist device. We report the case histories of patients who underwent removal of the device more than 4 years ago. METHODS: Since June 1994, 23 patients with end-stage idiopathic dilated cardiomyopathy who were supported by a left ventricular assist device or biventricular assist device for 1 to 26 months (mean, 6 months) underwent removal of the device after complete or extensive cardiac recovery, as revealed by echocardiography. RESULTS: Seven patients (group A) had recurrent cardiac failure after 4 to 24 months. Transplantation was performed in 6 patients, and one died while on the waiting list. Three patients died of noncardiac causes within a period of 4 months and 3 days after removal of the assist device. Stable cardiac recovery occurred in 13 patients (group B) for 3 to 49 months (mean, 23 months). At the time of implantation, there were no significant differences between the groups with regard to age, hemodynamics, left ventricular ejection fraction, left ventricular internal diameter in diastole, and autoantibody levels. The increase of ejection fraction and the decrease of left ventricular internal diameter in diastole after 2 months were highly significant. The patients in group A had longer histories of heart failure and first cardiac symptoms and duration of assist when compared with group B. Group B demonstrated a quicker cardiac recovery on the assist device, and thus support was shorter. Also, the degree of recovery at assist device explantation was more complete in group B. The age at the time of device placement was the only influencing factor for duration on the assist device. The probability of recurrence of heart failure was influenced by the duration of heart failure. CONCLUSIONS: In selected patients with idiopathic dilated cardiomyopathy, lasting recovery can be achieved after unloading with a left ventricular assist device. Lasting cardiac recovery seems to be related to functional normalization and a more rapid recovery during the unloading period.

Adolescent↗
PubMed1990

[Follow-up of surgical therapy in patients with threatened and acute myocardial ischemia for an average of 5 years].

Out of a total group of 300 patients after local intracoronary fibrinolysis, systemic ultra-high short-term fibrinolysis and instable angina pectoris 73 (24% out of 300) patients, in whom acutely or in the course of the treatment a surgical therapy of their coronary heart disease was performed, were analysed. Constellations of the findings of the coronary heart disease, when according to this connection with an adequate conservative therapy on the basis of a diagnostic and therapeutic step programme in 44% of the patients an improvement of the load capacity and in 73% an improvement of the subjective well-being is to be stated. In patients with diseases of one vessel compared with patients with diseases of several vessels significantly more frequently an intraindividual increase of the bicycle-ergometric performance develops.

Angioplasty, Balloon, Coronary↗
PubMed1990

[Diagnostic value of digital subtraction angiography in chronic venous insufficiency].

The first 117 investigations in chronic venous insufficiency by means of the technique of digital subtraction angiography (DSA) are reported. According to our experiences hitherto made this technique with peripheral intravenous injection of contrast remedies is excellently suited for the phlebography of the pelvic and vena cava regions as well as of the region of upper arm and shoulder, not so much, however, for the phlebography of the leg. By decrease of the concentration of the contrast remedy and the total quantity of the contrast remedy a reduction of the patient's stress and the risk of the examination is the result.

Angiography, Digital Subtraction↗
PubMed1990

[Phlebodynamometry studies in patients with chronic venous insufficiency and phlebography verified insufficiency of muscle veins].

23 patients with complaints in the sense of a chronic venous insufficiency were examined by means of phlebodynamometry, who phlebographically did not show any postthrombotic changes of the deep conducting veins, but had clear signs of an insufficiency of the muscle veins stage I-III. Cases with isolated insufficiency of the muscle veins (n = 5) and combination forms with additional insufficiency of the conducting veins and/or superficial varicosis (long and short saphenous veins) were found. Measured at the decrease of pressure (delta-p) after exercise in the combined forms the epifascial varicosis has the greatest haemodynamic effects. The isolated findings of an insufficiency of the muscle veins with or without additional insufficiency of the conducting veins has apparently only smaller haemodynamic effects. For the isolated insufficiency of the muscle veins normal limit values for delta-p could still be measured, which also could only insignificantly be bettered by application of a tourniquet. This knowledge is important for therapy planning.

Humans↗
PubMed1989

[The significance of a staged diagnostic-therapeutic program for the disease course in patients following unstable angina pectoris during a follow-up period of 3 1/2 years].

Among a group of 160 patients (146 men and 14 women) who had been admitted to our hospital under the picture of an unstable angina pectoris and whom we treated according a standardized diagnostic-therapeutic step programme 8.7% of the patients died of a cardiovascular disease during a period of 3 1/2 years. In 8% of our patients an acute myocardial infarction occurred during the period of observation. A diagnostic-therapeutic step programme was the basis for a differential therapy adapted to the individual course of the disease. We think that this therapy concept first of all corresponds to the individual dynamics of the course of the disease of patients with coronary heart disease.

Angina Pectoris↗
PubMed1989

[Percutaneous catheter embolization of the of the internal iliac artery in life-threatening gynecological bleeding].

16 patients with life-endangering hemorrhages caused by gynecologic malignancies have been treated with the percutaneous transcatheter embolisation. In general for embolisation of the internal iliac artery gelfoam was used. Life-endangering bleeding could be stopped in all cases, only 3 mild persistent bleedings and another recurrence of hemorrhage could be controlled conservatively. Major-complications did not occur. The significant advantage of catheter embolisation in controversy to surgical treatment is discussed.

Adult↗
PubMed1989

[Diagnostic strategy in suspected renovascular hypertension].

iv-DSA is an excellent method for detecting suspected stenosis of the renal arteries. In essential hypertension among 19 patients a frequency of 15.8% was found, in patients with accelerated hypertonus (n = 23) the percentage of renal artery stenosis was twice this rate (30.4%). In case of a positive or unclear outcome of iv-DSA, intraarterial angiography with ever ready PTRA is advisable.

Adolescent↗
PubMed1988

[Local intra-arterial fibrinolytic therapy in acute vascular occlusions in the area of the internal carotid artery].

Report on the first experiences with the local intraarterial streptokinase therapy in 5 patients with acute obliteration processes of the vascular system of the internal carotid artery. Two peripheral obliterations (occlusions of the main branch of the media) could be completely recanalised, with complete regression of the neurological symptomatology. In one of the three complete occlusions of the internal carotid artery (region of the siphon) a considerable partial recanalisation could be achieved. A fourth patient could be dismissed with an essential clinical improvement 11 days later despite angiographic persistence of the occlusion. Two patients died. As directive value for the dosage from 50,000 to 100,000 units streptokinase are proposed as short-term infusion in 30 to 60 minutes.

Acute Disease↗
PubMed1988

[Associated thrombotic processes of the superficial, perforating and intramuscular venous system in patients with acute phlebothrombosis of the lower extremities].

In a retrospective study 100 phlebograms of the legs of patients with definitive acute phlebothrombosis were examined for additional thrombotic processes in the superficial venous system, in the perforating and muscular veins. They could be confirmed in 77% of the cases, whereby preferredly the superficial venous system (long saphenous vein and lateral branches) were affected. A temporary coordination of superficial thrombophlebitis and phlebothrombosis cannot be made. At first it is adhered to the approved strategy of diagnosis that an acute superficial thrombophlebitis is no indication for phlebography. It is demanded the immediate application of invasive and non-invasive examination methods, when there is the least clinical suspicion of a deep venous thrombosis.

Female↗
PubMed1988

[Acute phlebographic diagnosis of thrombotic complications in gynecology and obstetrics].

From 1971 to April 1986 phlebography was performed in a total of 459 patients suspected clinically having an acute phlebothrombosis. From 112 female patients (24.4%) coming from the departments of gynaecology and obstetrics in 94 cases an acute or subacute phlebothrombotic process was proved phlebographically. The main age of these female patients was 29 +/- 11 years (17 to 76 years). A combined ileo-femoral-crural vein thrombosis in 44.7% was the most frequent localization and expansion, however, an isolated thrombotic process of pelvic veins was found in 25.6% only. A coincidence of the calculated age of thrombosis and clinical symptoms could be proved in 62 female patients (66%), but often the phlebographically calculated thrombus age was much longer than suspected by clinical symptoms alone. Foudroyant pulmonary embolism was observed in each fifth or sixth patient. The special technique of phlebographic investigation is discussed in detail with the judgement of a differentiated therapy of phlebothrombosis and pulmonary embolism.

Adolescent↗
PubMed1987

[Initial experience using percutaneous transluminal coronary angioplasty in the immediate management of acute myocardial infarct].

Reported in this paper is experience obtained from coronary diagnosis and coronary fibrinolysis in acute myocardial infarction. Local fibrinolysis was applied to 69 patients, with 2 X 75,000 units of streptokinase in 30 minutes being the dose for orientation. Percutaneous transluminal coronary angioplasty was added in those cases in which therapeutic fibrinolysis proved to be insufficient. An additional bypass operation was required by nine patients.

Angioplasty, Balloon↗