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Biomedical subjects

I Babotai

Publications and source records attributed to I Babotai.

At least 19 recordsLinked to original sources

[Indications and new developments in pacemaker therapy].

In the course of the past 25 years the indication for pacemaker implantation has changed from AV-block to the sick sinus syndrome in about 40% of patients. In the same period pacemaker technology has developed considerably and today there are, in addition to the ventricular inhibited pacemaker, two-chamber systems (essentially DDD pacemakers) and pacemakers with an increasing pulse rate during physical effort. The new nomenclature, mode of action and hemodynamic implications of the various systems are explained, and recommendations for implantation are given.

Electric Power Supplies

[2 years of clinical experiences with lithium pacemakers].

Between January 1974 and December 1976, 470 mercury-cell pacemakers and 353 lithium-cell pacemakers were implanted at Surgical Clinic A of the University Hospital of Zurich. Within the first 24 months 15.5% of the mercury-cell pacemakers had to be exchanged because of premature battery depletion and 1.3% due to dysfunction of electronic components. None of the lithium-cell pacemakers had to be removed for these reasons. In 6 lithium-cell pacemakers, however, overhaul was necessary because of sensing failure. One unit had to be removed after one year for local decubitus. In two cases, repositioning of the batteries was necessary because of local muscle stimulation.

Humans

[Various blood-foreign body reactions in the heart-lung machine in heart valve replacement and aortocoronary bypass operations].

Blood-foreign material interaction in the pump oxygenator was studied by means of scanning electron microscopy in 3 patients undergoing heart valve replacement (HVR) and 3 patients undergoing coronary bypass operation (CBO). While polyvinyl tubes show an average deposit of 60 thrombi/mm2 with 20--40 microns in size in CBO, bloodgas interface during HVR causes increasing thrombotic deposits (375 Mcthr/nm2, 25--50 microns in size). Distal to the pump the volume of particles may rise up 250 micrometer in HVR and up to 80 micrometer in CBO. In a 35 micrometer pore arterial-line-filter (Pall-Corporation) platelet clumps up to 1 mm in size are removed from circulating blood in HVR, and up to 300 micrometer thrombi in CBO. According to different platelet deposit proximal to the filter, more and larger thrombi can pass through the filter in HVR. Distal to the pump thromboemboli of 30--60 (maximum 90) micrometer in size can be observed in HVR. Particles of 20--35 (maximum 60) micrometer in size may pass through the filter and enter into the patient's circulation in CBO. As the results suggest, extracorporal circulation is more harmful for patients undergoing HVR than for those undergoing CBO.

Blood Cells

[Animal experiments with a new intracardial pacemaker electrode].

In order to reduce the rate of dislocation of intracardiac pacemaker electrodes, a new electrode was developed. The tip of this new electrode is helical and can be fixed between the trabecles of the right ventricle by clockwise rotation. Since the tip of this new electrode has no sharp hooks the myocard cannot be damaged by fixation.

Animals

[Evaluation of the interaction between blood and foreign material in the pump oxygenator during open-heart surgery in infants by scanning electron microscopy (author's transl)].

Scanning electron microscopy was used to elucidate the interaction between blood and foreign material in the pump oxygenator during open-heart surgery in 7 infants. The loss of platelets upstream of the blood pump is caused by thrombogenicity. The pump itself causes massive destruction of platelets and red blood cells; thromboembolie up to 100 mu and foreign body particles up to 200 mu are being detached from the wall of the tubing to a large extent. The particulate matter is trapped in arterial line filter. Particles up to 40 mu and cellular aggregates up to 60 mu can pass through the filter and enter the patient's systemic circulation.

Blood