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Biomedical subjects

H J Bisping

Publications and source records attributed to H J Bisping.

15 recordsLinked to original sources
PubMed1980

Improved technique in permanent atrial pacing.

At the present time, the relatively high atrial stimulation threshold and the low and often unstable P wave amplitude are the main concerns in atrial pacing. As a further contribution to the solution of this problem we used a screw-in atrial lead in 16 patients. During the implantation, atrial mapping was performed in order to establish the position with the best electrical performance. The acute threshold for voltage at a pulse duration of 1 ms averaged 0.49 +/- 0.18 Volt. The acute peak-to-peak P wave amplitude averaged 4.6 mV +/- 1.3. No complication occurred at the time of the implantation. Follow-up periods averaged 12 months. No dislocation or bleeding was observed during a follow-up period of up to 28 months. Using this lead together with intraoperative atrial mapping, it is possible to achieve an acute strength-duration relationship in the atrium at a level similar to that in the ventricle. The results of this study demonstrate that intraoperative mapping is an important stein in enhancing the safety margins and long-term performance of atrial pacing.

Action Potentials↗
PubMed1980

Three-year clinical experience with a new endocardial screw-in lead with introduction protection for use in the atrium and ventricle.

There is still a high incidence of dislodgement, threshold rises, and loss of sensing with permanent transvenous endocardial leads. Atrial leads are an even greater problem and require particularly reliable methods of fixation. In March, 1976 we reported our preliminary results from animal experiments using a new transvenous screw-in lead with introduction protection. This lead differs from other screw-in models as its spiral tip is retracted in the insulating tube during insertion. For fixation purposes a torque is applied to the proximal end of the conductor coil, which is loosely positioned within the tube, and this moves the helical electrode forward. One hundred and fifty endocardial electrodes have been implanted; 127 of them in the dilated ventricle and 23 in the atrium. The technique of introducing the lead into the vein (cephalic or jugular) was the same as that for conventional leads. It was easy to manage and quite uncomplicated. The fixation features in the atrium or the ventricle were sufficiently reliable to allow some patients to go home several hours post-implant. The total working time of the leads used has been 900 months; the overall complication rate is 2%.

Adolescent↗
PubMed1978

Electromagnetic interference in implantable pacemakers.

The inhibited pacemaker (VVI or AAI) has become the most popular in recent years because of its ability to combine a physiological advantage with economical current consumption in cases with spontaneous activity. One of its disadvantages is its sensitivity to external electromagnetic interference. Though today's pacemakers possess effective protection against most interference signals there may be instances in which patients are subjected to uncomfortable or even life-threatening situations. This is the case of "amplitude modulated" or "pulsed" fields with modulation frequencies in the physiological range. Fields of that sort have been found in the vicinity of a welder, an electric steel plant, and in medical practice where therapeutic currents were applied. Even touch-actuated switches may influence a demand pacemaker. However, these situations may be overcome by a device within the pacemaker for simple time analysis which can be carried out with few components. If electromagnetic fields of diathermy equipment are applied, today's pacemakers may react with intolerably high or low rates. They should, therefore, be avoided.

Electromagnetic Phenomena↗
PubMed1977

[Radiation therapy in patients with electronic cardiac pacemakers: interferences with the pacemaker's function by ionizing radiation and other sources of disturbances (author's transl)].

In the course of radiation therapy and connected diagnostical measures ionizing radiation and other sources of disturbance may interfere with the function of permanent pacemakers. The conditions of such hazards are investigated in theory and practice making allowance for the different susceptibility to trouble of various models of permanent pacemakers. It appears that no extension of long-term follow-up of the cardiac pacemaker's function is needed with regard to possible late effects of ionizing radiation, but that the follow-up of pacemaker-patients during their first period of treatment should not be neglected, since other sources of electronic interference may be present. Routine checks as radiotherapy installations should also include possible sources of disturbance to electronic pacemakers.

Aged↗
PubMed1977

[First clinical experiences with a new transvenous endocardial screw-in lead (author's transl)].

From November 1976 to January 1977 a total of 10 patients were served with a new transvenous endocardial screw-in lead. In every 5 cases the lead was anchored in the right atrium respectively in the right ventricle. The lead presented itself by good biomechanical (flexibility, tension resistance) and bioelectrical properties. Because of its constructural features it was to insert easily and without any complication. Moreover, it could be placed anatomically stable by choice either in the right atrium or ventricle.

Aged↗
PubMed1976

[Influence of radio and television sets on implanted cardiac pacemakers (author's transl)].

Investigations done on implanted pacemakers with a low threshold against extraneous signals and in-vitro tests under suitable conditions both showed that pacemaker wearers may go near television and accessories such as ultrsound distant control or flexless infrared ear phones without any danger. Radio and television sets are fitted to an increasing degree with electronic sensor switches which initiate various functions after a slight touch. This satisfies present regulations of German Electrical Engineers concerning permitted contact currents. However, pacemaker patients can cause impulse defects by use of sensor switches provided the contact current is less than 25 muA. Sensor technique will in the future be introduced for everyday use on a large scale. Therefore, pacemaker patients should be alerted to the possibilities of an influence, and industry should be made to reduce contact currents in sensors to values below 20 muA.

Infrared Rays↗