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Biomedical subjects

K Steinbach

Publications and source records attributed to K Steinbach.

At least 19 recordsLinked to original sources
PubMed1992

[Acute management of myocardial infarct patients in Austria (cross-sectional study of 8 intensive care units)].

8 Austrian Intensive Care Units provided data from 6,317 cases (including 1,667 cases with acute myocardial infarction) admitted during 1990 and 1991 for a documentation system offered by the Austrian Heart Foundation. Significant differences were observed between the units concerning admission policies and the use of diagnostic methods. 71% of the AMI cases were first infarctions, 10% were Non-Q-infarcts. The median of the prehospital period varied between 2.5 and 6.5 hours. The evaluation of the admission mode showed that on average 42% of the AMI cases had contact to their G.P. before hospital admission, this figure varying, however, between 24 and 90% in different areas. It seems that this contact takes place to a much lower extent in big cities. On average G.P. contact before hospital admission in AMI resulted in doubling of the duration of the prehospital period. Thrombolytic treatment was applied in 24.7% of AMI cases with a variation between 13.9 and 48.4% in the different centers. It is suggested that regular use of this kind of quality control should offer means for optimizing the acute care of infarct patients on a regional and on a national level.

Adult↗
PubMed1992

[Non-drug therapy of ventricular tachycardia/ventricular fibrillation].

In the majority of patients with ventricular tachycardia/fibrillation drug treatment is not effective. The non-pharmacological treatment of this high-risk patients is of increasing importance. In Austria about 900 patients per year need non-pharmacological treatment of malignant ventricular arrhythmias. For this purpose 4 or 5 specialized centers would be necessary.

Anti-Arrhythmia Agents↗
PubMed1992

[Value of a provocation test with diprafenone in patients with bifascicular block].

The significance of provocative tests in patients with bifascicular block is not established. We studied 14 patients with bifascicular block, syncope and documented episodes of high degree AV-block. 1.5 mg/kg Diprafenon was given after a period of at last 12 hours 1:1 AV-conduction. Electrophysiologic evaluation was performed before and after diprafenon. AV-block III could be provoked in 1 of 14 patients with Diprafenon. Therefore a total AV block occurred in 7% of patients. The low sensitivity of provocative test with Diprafenon even in patients with documented high degree AV-block prevents its application in clinical practice.

Aged↗
PubMed1991

Reductive formation of carbon monoxide from CCl4 and FREONs 11, 12, and 13 catalyzed by corrinoids.

In an earlier publication, we reported that corrinoids catalyze the sequential reduction of CCl4 to CHCl3, CH2Cl2, CH3Cl, and CH4 with titanium(III) citrate as electron donor [Krone, U. E., Thauer, R. K., & Hogenkamp, H. P. C. (1989) Biochemistry 28, 4908-4914]. However, the recovery of these products was less than 50%, indicating that other products were formed. We now report that, under the same experimental conditions, CCl4 is also converted to carbon monoxide. These studies were extended to include FREONs 11, 12, 13, and 14. Corrinoids were found to catalyze the reduction of CFCl3, CF2Cl2, and CF3Cl to CO and, in the case of CFCl3, to a lesser extent, to formate. CF4 was not reduced. The rate of CO and formate formation paralleled that of fluoride release. Both rates decreased in the series CFCl3, CF2Cl2, CCl4, and CF3Cl. The reduction of CFCl3 gave, in addition to CO and formate, CHFCl2, CH2FCl, CH3F, C2F2Cl2, and C2F2Cl4. The product pattern indicates that the corrinoid-mediated reduction of halogenated C1-hydrocarbons involves the intermediacy of dihalocarbenes, which may be a reason why these compounds are highly toxic for anaerobic bacteria.

Carbon Monoxide↗
PubMed1991

Acute myocardial infarction in juvenile patients with normal coronary arteries.

Three patients below 21 years of age presented with typical symptoms, electrocardiographic pattern, and levels of enzymes suggestive for acute myocardial infarction. Various risk factors for coronary artery disease were present in all three patients. Coronary angiography showed normal coronary arteries in all. Thus, acute myocardial infarction may be experienced even in very young patients. Clinical and angiographic findings are discussed on the basis of the existing reports in the literature.

Adrenergic beta-Antagonists↗
PubMed1989

[Silent ischemia in long-term ECG in the early post-infarct period].

101 consecutive patients (73 m, 29 f; 48 AMI, 53 IMI) under 70 years were assigned to 24 hour-Holter monitoring in the third week after first transmural infarction. ST-segment analysis could be performed in 88 patients (89%). 18 patients (20%) had episodes of ischemia which were silent in 95%. One third of these episodes occurred in the absence of physical exercise. Ischemic events displayed a circadian rhythm with a maximum between 6 and 12 a.m. There was no correlation between ischemia and the occurrence of ventricular arrhythmia. In addition, we show that visual control of automatic ST-segment analysis is a prerequisite for routine use in clinical practice.

Aged↗
PubMed1989

[Patient behavior and length of the prehospital phase in myocardial infarction].

120 of 272 consecutive patients (44%) with confirmed myocardial infarction reached hospital within three hours of onset of symptoms. Important delays were caused by the patients "treating" themselves with drugs (delay of 6.8 +/- 14.9 h) and/or other measures (11.1 +/- 15.7 h), and in 50 of 144 (35%) patients, who consulted a doctor, time-consuming diagnostic tests and therapeutic measures (10.9 +/- 12.6 h). On the other hand, severity of pain shortened the prehospitalization phase significantly (P less than 0.025). Age, time of day, infarct site or whether first-time or recurrent infarct had no influence on the time elapsed until admission to the intensive care unit. Thus advice to patients and instruction to doctors may be the most effective means of shortening the prehospital phase in patients with myocardial infarction.

Aged↗
PubMed1989

[Transvenous high frequency current ablation of atrioventricular conduction in therapy refractory tachycardic atrial fibrillation].

We present a case of radiofrequency ablation of the atrioventricular conduction system by means of intravenous catheter technique in a patient with drug-refractory paroxysmal atrial fibrillation. Total AV block was produced. Since the ablation and implantation of a pacemaker this female has had no recurrences. The advantages of this method compared with electrical fulguration are better control of delivered energy and reduction of complications (catheter perforation, thromboembolism). The disadvantage of radiofrequency ablation is the difficulty in positioning the catheter so as to give the most precise contact with the tissue, which is a very time-consuming procedure.

Aged↗
PubMed1989

Rapid identification of Haemophilus influenzae serovar b by gas liquid chromatography using carbohydrate fingerprints.

Carbohydrates from whole-cell hydrolysates of 18 strains of the species Haemophilus influenzae (5 strains belonging to serovar b) were analysed by gas-liquid chromatography. The identity of the carbohydrate components was confirmed by comparison with the retention times of reference sugars and by gas chromatography mass spectrometry. Evidence was obtained that Haemophilus influenzae serovar b can easily be identified by the presence of one large peak representing ribitol. The method described can be routinely applied in bacteriological laboratories equipped with a gas chromatograph. It gives results within approximately 4 h, it is reproducible and easy to perform. Even single colonies isolated directly from agar plates can be used for analysis without further subculturing.

Carbohydrates↗
PubMed1989

Problems of sensing tachyarrhythmias by an antitachycardia pacemaker (Symbios 7008).

Atrial burst pacing is an effective method of terminating supraventricular tachycardia. In the patient presented in this report, a Symbios 7008 pacemaker (Medtronic Inc., Minneapolis, MN, USA) was implanted for two reasons: (1) severe AV conduction defect (AH, 230 msec; HV, 150 msec) and bifascicular block following anterior myocardial infarction; and (2) paroxysmal atrial flutter. The conduction defect ruled out programming other than atrial burst in DDD mode. Activation of burst pacing required appropriate programming of the "tachycardia detection window" on the basis of the cycle length of the flutter waves. In the case reviewed, episodes of atrial flutter with variable cycle lengths of 230 to 280 msec necessitated reprogramming of the AV interval, the refractory period, and the upper rate interval. The use of an antitachycardia device in automatic mode may be limited by variations in tachycardia cycle length.

Aged↗
PubMed1988

[Treatment of ventricular tachyarrhythmias with an implantable cardioverter-defibrillator system].

5 patients (3 with coronary artery disease and chronic myocardial infarction, 2 with dilatative cardiomyopathy) with a mean age of 59 years (range 54-69 years) with drug refractory ventricular tachycardia and/or ventricular fibrillation received the automatic implantable cardioverter defibrillator (AICD). Intraoperative testing revealed a mean defibrillation threshold of 13 +/- 2.7 Joule. Over a mean follow-up period of 15.2 months (range 3-25 months) the patients received a total of 117 discharges. 15% of the delivered shocks were recorded during continuous ECG monitoring, 13% were associated with palpitations and 27% were discharged during syncope. 45% of shocks occurred in the absence of symptoms. No patient died suddenly. 1 patient died of intractable heart failure, 1 patient died of septic shock. In carefully selected patients the automatic implantable cardioverter defibrillator is an effective tool in the treatment of life-threatening ventricular tachyarrhythmias. Modifications of the device to incorporate programmability of the cut-off rate, the sensing criteria and the levels of shock energy, as well as the options for different pacing modes combined with memory functions are needed to improve antiarrhythmic strategies.

Aged↗
PubMed1988

Ketanserin combined with a beta-blocker or diuretic in essential hypertension. A multicentre study.

The antihypertensive effect of ketanserin 40 mg b.d. in combination with a beta-adrenergic blocking agent or a diuretic was assessed in an open study in 35 patients with essential hypertension, who had not responded to treatment with beta-blockers, diuretics or their combination. The ketanserin/beta-blocker combination decreased mean sitting systolic/diastolic blood pressure (SBP/DBP) from 169/107 mmHg to 156/91 mmHg at the end of the 12-week active treatment period. The decrease in systolic blood pressure was significant only at Week 8, while the decrease in diastolic blood pressure was highly significant at all times. A significant reduction in heart rate by 10 beats.min-1 was observed with the ketanserin + beta-blocker combination. The ketanserin/diuretic combination led to a significant reduction in mean SBP/DBP from 164/106 mmHg to 146/92 mmHg after 12 weeks, with no significant change in heart rate. Body weight slightly increased in both groups. There were significantly fewer adverse reactions with the ketanserin/diuretic combination than with the ketanserin/beta-blocker combination. The results indicate a potentially useful therapeutic role for ketanserin in combination with beta-blockers or diuretics.

Adrenergic beta-Antagonists↗
PubMed1987

Inhibitory effect of tetrachloro-p-hydroquinone and other metabolites of hexachlorobenzene on hepatic uroporphyrinogen decarboxylase activity with reference to the role of glutathione.

Exposure of rats to HCB caused a dose-dependent depletion of GSH. Chlorophenolic and sulfur-containing metabolites of HCB incubated with GSH-free rat liver cytosolic protein drastically diminished the UROD activity. In addition, HCB also exhibited inhibitory potency. The most effective compounds studied were TCH and its oxidation product, chloranil. Incubation of liver cytosolic protein and of GSH with HCB and its metabolites yielded results that suggested interaction between the compounds and cell constituents--an interaction that may cause inhibition of the hepatic UROD activity in the HCB-exposed organism.

Animals↗
PubMed1979

Studies on the toxicology of hexachlorobenzene. IV. Sulphur-containing metabolites.

After administration of hexachlorobenzene rats excrete sulphur-containing conjugates from which pentachlorothiophenol can be split off. In the present study we describe the identification of pentachlorothiophenol and pentachlorothioanisol in the livers of animals treated with hexachlorobenzene. In order to clarify the further fate of these two substances, we administered them to rats, and isolated the conversion products excreted in the urine and feces. The metabolites of pentachlorothiophenol and pentachlorothioanisol are excreted in both conjugated and free form. From extracts of the excreta, we isolated tetra- and trichlorobenzene with two or three sulphur-containing substituents on the ring, analogous compounds in which thiol groups were converted into sulphoxide and sulphone groups, as well as analogous compounds with a phenolic oxygen in addition to sulphur, and sulphur-containing compounds in which clorine was replaced by hydrogen. Following administration of the sulphoxide and of the sulphone of pentachlorothioanisol under analogous conditions, pentachlorothiophenol and pentachlorothioanisol and their metabolites were detected in the excreta of the animals. No evidence was obtained that the parent compounds are excreted in the unchanged form.

Animals↗
PubMed1979

[Documentation of arrhythmias - the value of long-term ECG monitoring].

Computer-supported long-term ECG-analysis, must be considered as complementary to other methods of documentation concerning arrhythmias. With the introduction of computers in the last several years, exact quantification and qualification of arrhythmias, over long monitoring periods, has become possible. With this method diverse forms of documentation and data presentation enhance its value of information and increase plausibility. Major indications for long-term ECG-monitoring of ambulatory patients are detection of occult arrhythmias, evaluation of subjective symptoms such as dizziness or syncope, recognition of pacemaker dysfunctions, selection of patients with coronary heart disease at high risk and evaluation as well as control of the efficacy of antiarrhythmic therapy.

Arrhythmias, Cardiac↗
PubMed1978

[Haemodynamic response to antihypertensive treatment with atenolol in patients with hypertension (author's transl].

The antihypertensive effect of atenolol, a cardioselective beta-blocker, was examined in 8 patients with essential hypertension. The most important haemodynamic changes observed were a significant reduction in heart rate (reduction in maximum heart rate at the end of symptom-limited exercise by 23% p less than 0.01) and a moderate fall in systolic blood pressure (reduction at submaximum level of exercise by 22%, p less than 0.01). The antihypertensive effect was attributable in half the patients to a drop in peripheral vascular resistance and in the other half evenly to a predominant reduction in cardiac output or to a reduction in both parameters. In view of the compensatory rise in stroke volume a significant reduction in cardiac output was not found. Symptom-limited exercise tolerance was increased in all patients. These results lead to the conclusion that the antihypertensive action of the cardioselective beta-blocker, atenolol is based on a lowering of the increased peripheral vascular resistance and a reduction in cardiac output; the latter mechanism is predominantly found in patients with hyperkinetic features.

Adolescent↗
PubMed1978

[Sudden cardiac death in patients with pacemakers].

The risk of sudden death in our material, is 13.6% of all deaths. 2. In 5 patients (1.6%) death was caused by failure of the pacemaker (PM), or the electrode. 3. Patients with an asynchronous PM have no higher risk for sudden death, than patients with demand PM. 4. In 9 of 44 patients, a dysfunction of the PM or electrode, can not be excluded. Thus, it must be strictly advised in all patients with an implanted PM, that an autopsy and control of the explanted PM and electrode should be performed. 5. Patients who have a higher risk for sudden death (total AV-Block, Adams-Stokes-Attacks) should be kept hospitalized at least 4 weeks after implantation, controlled more frequently than others, and should be labelled as high risk patients in their PM passport. 6. Control of the resistance in the patients circuit can detect impending failure of the electrode and prevent life threatening complications.

Death, Sudden↗