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Biomedical subjects

M Sigmund

Publications and source records attributed to M Sigmund.

17 recordsLinked to original sources

[Physical exercise tolerance in chronic obstructive emphysematous bronchitis and coronary heart disease under antiobstructive therapy].

19 consecutive patients (18 men, one woman, mean age 61.4 [49-73]years) with chronic obstructive airways disease (bronchitis and emphysema) together with angiographically confirmed coronary heart disease were studied to investigate their cardiopulmonary exercise tolerance and the effects of bronchodilators on their myocardial ischaemia. Because they were receiving drug therapy for angina or because they had previously undergone aortocoronary bypass operation or balloon dilatation, the patients were symptom-free. In three cases slight ischaemia was demonstrable during maximal exertion. Aerobic and anaerobic exercise capacity was determined by spiroergometry after inhalation of salbutamol (S, 0.2 mg) alone or in combination with oxitropium bromide (O, 0.2 mg). The supplementary effect of oral theophylline (T, 15 mg/kg.day) was studied in 13 patients. In terms of maximal aerobic exercise tolerance the following improvements were noted: energy output (watts): S: + 6.3%; S and O: + 12.3% (P < 0.05); S, O and T: + 14.0% (P < 0.01). Oxygen uptake (ml/min): S: + 8.2% (P < 0.05); S and O: + 18.2% (P < 0.01); S, O and T: + 35.4% (P < 0.01). Maximum exercise capacity was not significantly improved, although maximum oxygen uptake was significantly increased by the two-drug combination by 16.9% (P < 0.05) and by the three-drug combination by 19.2% (P < 0.05). Maximum minute volume and tidal volume rose significantly, though respiratory rate was unchanged. Heart rate and blood pressure remained practically unaffected by the treatment, both at rest and during exertion. There was no evidence of significant aggravation of ventricular arrhythmias or of ischaemia during ergometric testing.

Albuterol

Clinical results of automatic slope adaptation in a dual sensor VVIR pacemaker.

Manual slope programming in rate adaptive pacemakers can be time consuming. This may become worse with dual sensor devices. The remedy is to let the pacemaker automatically learn the slopes. Fast learning replaces initial manual slope programming. Daily learning is a continuous process to determine and optimize slopes during daily life. Both methods are known for a QT sensing pacemaker. Fast learning is known for other single sensor devices. The aim of this study was to follow daily learning in a QT and activity dual sensor pacemaker, starting with factory slope settings. Six patients were studied for about 8 weeks. The daily learning algorithm appeared to be effective, showing the desired regulation processes. It took 2-5 weeks to reach full rate response.

Acceleration

[Beta receptor blockers in dilated cardiomyopathy (clinical aspects)].

Results of 16 international published studies (with a total of 397 patients in NYHA-classes II-III) concerning chronic therapy with beta-adrenoceptor blockade in idiopathic dilated cardiomyopathy were analyzed. 8 studies were placebo controlled. Under beta-blockade cardiac output increased significantly by about 15% and ejection fraction by approximately 30%, apparently due to an improvement in contractility and relaxation of LV myocardium. Therapy was tolerated without complications in 93% of patients when the loading dose was 5 to 15 mg metoprolol/d (or equivalent) and a long-term dose of 100-200 mg/d metropolol (or equivalent) was reached within 4 weeks. Patients with severe heart failure (NYHA IV) had a higher risk of complications. A positive effect of beta-blockade in IDC was achieved in most cases but not earlier than after 2-3 months after initiating therapy. Despite these positive results beta-blockade in patients with IDC may not yet be recommended generally. Sufficient results of controlled trials are still lacking. Important questions with regard to the prognosis under beta-blockade, to the effects of cardioselectivity and intrinsic activity, and to the efficacy of this kind of therapy in the presence of ACE inhibitors have not been answered. Thus, major trials with controlled design are needed.

Adrenergic beta-Antagonists

[Electrocardiographic diagnosis of acute graft rejection after heart transplantation].

In order to evaluate the diagnostic value of standard-ECG (ST-ECG) and precordial mapping-ECG with 63 unipolar leads (PM-ECG) for detection of acute cardiac allograft rejection, 15 patients (12 male, 3 female; age range 24-64 years) were studied. ST-ECG and PM-ECG were recorded along with 94 endomyocardial biopsies. Twenty-four acute rejections were detected histologically. Using the ST-ECG, a reduction of the QRS-amplitude-sum (lead I, II, III, V1 and V6) greater than or equal to 5% in comparison with the ECG obtained 1 week before was found to be the best diagnostic criterion (sensitivity 63%, specificity 74%, positive predictive value 48%, negative predictive value 85%). By analysing the PM-ECG a drop of the QRS-amplitude greater than or equal to 12% in greater than or equal to 14/63 precordial leads was determined to be the most reliable parameter (sensitivity 79%, specificity 71%, positive predictive value 49%, negative predictive value 91%). In contrast to the high sensitivity of PM-ECG, ST-ECG was less suitable for detection of acute rejection. However, taking into account the high negative predictive value of PM-ECG, acute rejection could be excluded with high probability, if the QRS-amplitudes of the PM-ECG remained stable. This may lead to a lower frequency of routinely performed endomyocardial biopsies.

Adult

[Heart damage after electric injury].

Death from electrical accident due to low voltage (220 Volt/380 Volt) is usually caused by ventricular fibrillation. In humans who sustain non fatal electrical injury abnormal ECG findings due to myocardial damage are rare. 243 (76%) of 320 ECGs of survivors of an electrical accident were diagnosed as normal. In 42 patients (13%) unspecific electrographic changes were seen and in 35 (11%) abnormal ECGs were found. In comparison to findings in normal populations no significant accumulation of ECG changes was observed. A causal relationship between abnormal ECG findings and electrical accident is only then probable if ECG abnormalities are documented immediately after injury and serial ECG controls demonstrate significant changes in comparison to the initial abnormality.

Adolescent

Distinct down-regulation of cardiac beta 1- and beta 2-adrenoceptors in different human heart diseases.

Cardiac beta-adrenoceptor density and beta 1- and beta 2-subtype distribution were examined in human left ventricular myocardium from transplant donors serving as controls and from patients with mitral valve stenosis, aortic valve stenosis, idiopathic dilated cardiomyopathy, and ischaemic cardiomyopathy respectively. The total beta-adrenoceptor density was similar in transplant donors and patients with moderate heart failure (NYHA II-III) due to mitral valve stenosis, but was markedly reduced in all forms of severe heart failure (NYHA III-IV) studied. A reduction of both beta 1- and beta 2-adrenoceptors was found in patients with severe heart failure due to mitral valve stenosis or ischaemic cardiomyopathy. In contrast, a selective down-regulation of beta 1-adrenoceptors with unchanged beta 2-adrenoceptors and hence a relative increase in the latter was observed in idiopathic dilated cardiomyopathy and aortic valve stenosis. It is concluded that the extent of total beta-adrenoceptor down-regulation is related to the degree of heart failure. Selective loss of beta 1-adrenoceptors is not specific for idiopathic dilated cardiomyopathy but also occurs in aortic valve stenosis. Changes in beta 1- and beta 2-subtype distribution are rather related to the aetiology than to the clinical degree of heart failure.

Adult

Asymptomatic left ventricular malposition of a transvenous pacemaker lead through a sinus venosus defect: follow-up over 17 years.

The case of a woman with an asymptomatic transvenous left ventricular endocardial pacemaker lead is presented. The chest X ray and the electrocardiogram suggested pacemaker catheter malposition. By two-dimensional echocardiography, the pacemaker lead was shown to cross from the left atrium through the mitral valve and implant in the left ventricular endocardium. The underlying sinus venosus defect and the passage of the electrode through this interatrial communication were directly visualized by transesophageal echocardiography. No thrombotic material attached to the lead was detected corresponding to the patient's uneventful course for surprisingly more than 17 years without evidence of past or present neurological deficiencies or of peripheral embolic phenomena. Thus, no operative correction was performed. Warfarin sodium therapy, however, was initiated.

Bundle-Branch Block

[Myocarditis caused by Toxoplasma gondii and Aspergillus fumigatus after orthotopic heart transplantation].

This report describes the case of a 56-year-old patient, who died 53 days after orthotopic heart transplantation due to myocarditis caused by infection with Aspergillus fumigatus and Toxoplasma gondii. Aspergillosis was diagnosed by transthoracic needle aspiration of a pulmonary infiltration. Endomyocardial biopsy showed toxoplasma pseudocysts. Autopsy revealed myocardial infection with both infectious agents. Despite specific therapy, myocarditis determined the fatal outcome in this case. The value of invasive techniques for specific diagnosis of infectious diseases in immunocompromised patients is discussed.

Aspergillosis

[Incidence of pathologic ECG findings in survivors of electric accidents].

ECGs of 320 male survivors of electrical accidents were examined. The results were compared with findings in normal populations reported in previous epidemiological studies. 243/320 electrocardiograms (75.9%) were considered to be normal. In 42/320 (13.2%) unspecific electrocardiographic changes were seen, and in 35/320 (10.9%) abnormal ECGs were found. No significant accumulation of ECG changes was observed in comparison to the control groups. Results confirm abnormal ECG-findings to be rare in humans who sustain non-fatal electrical injury. If an ECG is considered to be abnormal, a causal relationship is only probable if findings are documented immediately after injury, and if serial ECT controls demonstrate significant changes in comparison to the initial abnormality.

Adult

["QT" pacemaker in aggregate exchange. Do old electrodes impair functional ability?].

A "QT"-interval driven rate responsive pacemaker can also be implanted on the occasion of pacemaker replacement. To evaluate the electrophysiological properties and limitations of chronic leads, in 30 patients the evoked intracardiac electrogram was recorded via the chronic lead during pacemaker replacement (14 different types, mean interval after implantation 111 (25-171 months). T-wave detectability was evaluated with different pulse amplitudes (2.5 and 5.0 V) and two pacemaker systems (TX 915, Rhythmyx) with different "fast recharge" mechanisms. In particular, the T-wave signal was influenced by capacitor discharge effects. At 2.5 V output T-wave amplitude was greater than or equal to 1.5 mV in all (19) patients, who could be paced at this voltage. However, at 5 V in 9/30 patients T-wave was less than 1 mV and detection was not possible in 6/30 cases. During pacing with the newly developed "QT"-interval driven, rate-responsive pacemaker (Rhythmyx) with two fast recharge pulses, in nine investigated patients the T-wave was markedly better discriminable compared to the TX 915 pacemaker. Accordingly, in 37 patients with implanted "QT"-controlled pacemakers (TX 911): n = 13; TX 915: n = 21; Rhythmyx: n = 3. Indication for pacemaker therapy: high degree AV block: n = 24, sick-sinus syndrome: n = 13) reliable T-wave sensing was possible at 2.5 V/0.2 ms output, whereas at 5 V/2 ms no T-wave sensing could be achieved in 8/37 cases. On the occasion of pacemaker replacement the "QT"-controlled pacemaker can be implanted without intraoperative measurements, whenever a pulse amplitude less than 2.5 V is sufficient for stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiography

[A heart rate adaptable "physiologic" pacemaker. Is the effort worthwhile?].

The dual-chamber pacemaker provides an approximately physiologic cardiac action in patient with 3rd degree AV-block and preserved sinoatrial function. Newly developed so-called rate-responsive systems are now available. Initial clinical experience has been reported with pacemakers controlled via respiration rate, activity, central venous blood temperature, or intracardially measured QT-interval. The sensitivity and specificity of rate regulation like the effort of implantation and setting is not completely satisfactory and adequate until now. At the present time, such systems are being implanted mainly according to individual indications. Before a general use can be recommended, several problems still remain to be solved, in particular the question as to what therapeutic advantage is to be expected with respect to the underlying disease, arrhythmia and patient group.

Bradycardia

Simple method for rapid and highly sensitive detection of antiviral-antibodies in serum and cerebrospinal fluid of small laboratory animals.

A technique is described for the small-scale determination of antibodies in blood and liquor. Small sample volumes of about 3 microliter blood and 15 microliter liquor are sufficient to detect even low antibody titers against different proteins. Thus, for studying the timecourse of antibody titers, repeated examinations of small laboratory animals are possible. The method includes the highly reproducible separation of the antigens in a 45 X 35 X 0.5 mm polyacrylamide gel (6.5%) using the Phast-system (Pharmacia), followed by electrotransfer and immunostaining. The whole procedure takes less than five hours.

Animals

PEDPLO: a pedigree plot program.

The program PEDPLO supports the graphical presentation of inheritance. The plot produced is a tree ramifying towards the younger generation. There is only little dependence on the special software and hardware of the plot.

Computers