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Biomedical subjects

P Stirbys

Publications and source records attributed to P Stirbys.

6 recordsLinked to original sources
PubMed1990

A method for estimating endocardial electrode stability.

Assessment of cardiac pacing electrode stability following implantation is of major importance. We describe a method of testing electrode stability using a provocative test. The method includes synchronized electrical pacing of the left phrenic nerve by an especially designed external pacemaker. A positive response is abrupt, a diaphragmatic contraction, which in turn induces an abrupt heart movement in its diastole, its relaxation phase. Fifty-six various endocardial electrodes were tested in this fashion. Seven electrodes, one with flange tip, two tined, and four had no fixation dislodged after this pacing test. Insignificant elevation of acute ventricular pacing threshold was observed. While this method appears to be advantageous, additional clinical data is necessary.

Animals↗
PubMed1988

Implantation of double screw-in leads.

Since 1978, 600 double screw-in leads have been implanted, 320 in the ventricle and 280 in the atrium. Four episodes of cardiac perforation, one of which was lethal, have occurred during guide-catheter insertion. The electrode is now coated with polyglycol which is blood soluble and covers the electrode hooks during introduction into the vascular system without a guide catheter. The electrode hooks are exposed and can be attached to the endocardium. Three atrial leads, 1.07% and one ventricular lead, 0.31%, have become dislodged. Total dislodgement has thus been 0.67%.

Cardiac Catheterization↗
PubMed1986

Permanent interatrial septal pacing: feasibility and advantages.

One hundred eighty-nine implanted atrial pacing leads have been analyzed. A double screw-in active fixation lead was attached to the interatrial septum in eight patients and a J lead in one patient. The right atrial appendage was the site used in the 97 other patients with a double screw-in lead; a J-shaped lead was used in three and an anchored (active fixation) lead in the remaining 80 patients. Though pacing from the interatrial septum has different characteristics of lead stability, it offers a number of advantages over right atrial appendage stimulation.

Aged↗
PubMed1978

Permanent cardiac pacing with electrodes of a new type of fixation in the endocardium.

To improve electrode construction the following main problems have been considered: (1) reliable initial fixing in the endocardium, and (2) reducing the area of contact surface and improving threshold values. In this article we have described three original electrodes: 1) an endocardial electrode with a multi-edged tip (contact area 28 mm2), which gives high electric field strength and low thresholds; 2) a spreading tip electrode, which was created on the basis of morphological data. The tissues grow into the spread spaces of this tip and ensure better stability (contact area 17.8 mm2); and 3) a double-screw-in electrode which differs from the other corkscrew types. The contact end (surface area--10.4 mm2) consists of two sickle-shaped hooks. The sickle handle is 0.7 mm in length which prevents further hook penetration in the wall of the heart. It was found that a multi-edged electrode and electrodes supplied with a fixation device are, in terms of energy consumption, more effective compared to electrodes with spherical or cylindrical tips of the same area of contact surface. The double-screw-in endocardial electrode has useful features: reliable fixation and a small contact surface area and, therefore, a low threshold value. Thirty-five double-screw-in electrodes were inserted into an atrial position and 28 into a ventricular position. We have not observed any displacement of such electrodes during the past two years.

Cardiac Pacing, Artificial↗