The localisation of the electrode in permanently paced heart--an echocardiographical study.

Unlabelled: Permanent cardiac pacing is a widely applied procedure in invasive cardiology. The aim of our study was the analysis of the localisation of the tip of the pacemaker lead and its course in the right ventricle. Research was carried out on a group of 12 patients (5F, 7M), from 40 to 93 years of age (average 70 +/- 15 yrs) with permanent cardiac pacing or implantable cardioverter-defibrillator (ICD). Subsequent echocardiographic views were applied: an apical four chamber view, a subcostal one and a parasternal right ventricular inflow tract view. At the level of the tricuspid annulus the electrode was positioned: the anterior leaflet--41.7% (5 pts), the anteroseptal commissure 25% (3 pts), the posterior leaflet 8.3% (1 pt) and the septal one--8.3% (1 pt). In 16.7% (2 patients) the lead was positioned centrally in the right atrioventricular orifice. Regarding the further positioning of the electrode in the ventricle, in 41.7% (5 pts) the leads were placed along the interventricular septum, in 16.7% (2 pts) along the anterior wall of right ventricle and in 41.7% (5 pts) across the centre of the right ventricle. The tip of the lead was positioned in the apex of the right ventricle in 83.4% (10 pts). In the remaining 16.7% (2 pts) the position was not apical--in 1 patient the anterior wall of the right ventricle and in 1 patient the interventricular septum. In the VVI pacing mode the electrode did not lie on the interventricular septum. In contrast to this in 80% of patients (4 pts) having the DDD pacing mode the lead was situated on the interventricular septum on its course downwards to the ventricle.

Conclusions: 1) On the level of the leaflets of the tricuspid valve the lead most often was positioned at the level of the anterior leaflet and the anteroseptal commissure. 2) Most patients had an apical localisation of the tip of the lead. 3) Differences between morphological and echocardiographic studies are related to the intravital and the two-dimensional character of echocardiography, and probably to the small population of the group examined.