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 fcontact 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.