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Biomedical subjects

H Weber

Publications and source records attributed to H Weber.

At least 487 records · Page 27Linked to original sources
PubMed1981

[Quantitative evaluation of an antiarrhythmic therapy (disopyramide) in patients with frequent premature ventricular contractions (PVC) using a computer-assisted long-term ECG analysis system (author's transl)].

15 patients (pts.) - 12 males, 3 females - with frequent PVC (greater than 3%/16 hr during a qualifying period = LP) of different causes underwent after one-day placebo application (PL) drug treatment (disopyramide: loading dose 600 mg, 300 mg t.i.d.) over two days (D1, D2). The ambulatory continuously recorded long-term ECG was analysed using "Multipass-Scanning", a computer-supported analysis system for quantification of therapeutic success. The mean PVC rate of 17% prior treatment could be diminished in 87% of the pts. significantly. 5 pts. (group I) demonstrated a maximal PVC-reduction rate of more than 90 rel %. Among them in 2 pts. the PVC-rate did not exceed the 1%-level during D1 and D2 demonstrating an optimal therapeutic success. The max. PVC-reduction rate ranged between 80 and 90 rel % in 3 pts. (group II) and between 38 and 78 rel % in 5 pts. (group III). 2 pts. did not respond on DP. The mean DP-plasma level was higher in group-III pts. than in group-I or -II pts. in spite of a less therapeutic success. 7 pts. demonstrated a circadian behaviour of PVCs. Therefore the circadian variability increased. Also lower PVC rates under DP (D1, D2) led to an increase of spontaneous variability of PVCs. The maximal PVC depressant effect of DP appeared while the heart rate was 70 b.p.m. or higher. In conclusion, 87% of the pts. demonstrated a drug effect, but an effective antiarrhythmic therapy occurred only in 2 pts. (13%). A decrease of the frequency of rhythm disturbances led to a decrease of arrhythmia's variability and requires a prolongation of the ECG-recording time to eliminate the variabilities of arrhythmia occurred (spontaneous, circadian) and to avoid a mimicked therapeutic success.

Adolescent↗
PubMed1981

[The "steal" syndrome and the development of pulmonary arterio-venous shunt after Glenn and/or Fontan operations (author's transl)].

18 patients with superior vena cava-right pulmonary artery (Glenn) anastomosis and 7 patients with right atrium-pulmonary artery (Fontan) conduit operation were investigated by selective angiography, oximetry and contrast echocardiography. 11 patients with Glenn anastomosis (61.1%) developed a "steal" syndrome in 4 11/12 to 9 7/12 years postoperatively. In 2 patients pulmonary arteriovenous shunt could be documented by selective angiocardiogram, oximetry and contrast echocardiography, and in 1 patient by contrast echocardiography only (16.6%). None of the patients with Fontan operation developed detectable pulmonary arteriovenous shunt in the follow-up period. The effect of the changed haemodynamics after Fontan operation on the "steal" syndrome in patients with prior performed Glen anastomosis is that to diminish or abolish collateral flow. There is no influence on the abnormal intrapulmonary arteriovenous communications.

Adolescent↗
PubMed1981

[New aspects in the pathogenesis of the prolonged QT-interval syndrome with syncopal attacks. Intracardiac ECG recordings during atrial stimulation in 4 patients (author's transl)].

Three families with the syndrome of hereditary prolonged QT interval affecting 12 members in two or three generations are described. Four patients with sinus bradycardia and frequent syncopal attacks were investigated by Holter-monitoring, His-bundle electrograms and exercise testing. Corrected QT intervals (QTc) were prolonged from 0.43 to 0.54 seconds at rest. In His-bundle electrograms, during atrial pacing at increasing rates the function of the entire conduction system seemed to be affected. Three patients were treated with pindolol and one patient with a permanent demand pacemaker and pindolol. During progressive exercise testing performed after drug therapy or pacemaker treatment, heart rate increased unsatisfactorily and QTc-intervals lengthened whereas atrial stimulation QTc-intervals remained unchanged. In the patient with a permanent demand pacemaker, electrocardiographic monitoring revealed a period of 25 seconds of ventricular tachycardia occurring at rest and ceasing spontaneously. In the past 1.2 years to 2.5 years (mean 2.1 years) of outpatient follow-up, the patients had normal exercise tolerance and syncopal attacks did not occur on pindolol 30 mg/day. Our findings suggest rather a hypersensitivity of the affected conclusion system in the presence of a normal activity of cardiac sympathetic nerves.

Adolescent↗
PubMed1981

[Hypertensive pulmonary vascular disease in complete transposition of the great arteries (author's transl)].

Pulmonary vascular disease and heart failure are the two major problems in complete transposition of the great arteries (TGA) with increased pulmonary flow. Hypertensive pulmonary vascular disease was observed in patients with complete TGA and increased flow (3.6%) as well as in those without increased pulmonary flow (3.3%). An intact ventricular septum or pulmonic stenosis did not appear to prevent the occurrence of progressive pulmonary vascular disease in all patients. The pulmonary lesion observed in these subjects cannot be explained by chronic severe volume overload alone. Clinically unrecognized pulmonary microthrombi are an additional cause for the development of pulmonary vascular disease in patients with complete TGA. Therefore cyanosis and its complications can be a major factor beside increased pulmonary flow in causing pulmonary vascular changes. Early corrective surgery performed after the age of 3 months is the therapy of choice to avoid progressive pulmonary vascular damage and other thrombo-embolic accidents.

Cardiac Catheterization↗
PubMed1980

Myosin types in human skeletal muscle fibers.

By combining enzyme histochemistry for fiber typing with immunohistochemistry for slow and fast myosin a correlation between fiber type and myosin type was sought in human skeletal muscle. Fiber typing was done by staining for myofibrillar ATPases after preincubation at discriminating pH values. Myosin types were discriminated using type specific anti-rabbit myosin antibodies shown to cross-react with human myosin and were visualized by a protein A-peroxidase method. Type I fibers were shown to contain slow myosin only, type IIA and IIB fibers fast myosin only, and type IIC fibers both myosins in various proportions. When muscle biopsies from well-trained athletes were investigated essentially the same staining pattern was observed. However, rarely occurring type I fibers with high glycolytic activity were detected containing additional small amounts of fast myosin and occasional type IIA fibers had small amounts of slow myosin. Based on the observation of various fiber types in which slow and fast myosin coexist we propose a dynamic continuum of fibers encompassing all fiber types.

Adenosine Triphosphatases↗