[Diagnosis of endocardial electrode microdislocation at endocardial pacing]

Signs of microdislocation of an endocardial electrode (EE) were observed in 56 (14.4%) of 390 patients with an implantable pacemaker in the postoperative period. The microdislocation was diagnosed from electrocardiographic evidence for no response of a pacing pulse and from fluctuations in the pacing threshold, and from X-ray findings of the thickened and ill-defined outlines of a distal EE with preserving cardiac stimulation. The microdislocation preserves high parameters, as evidenced by a PM-20 M digital analyzer.