title: Unconventional approaches to cardiac pacing in patients with inaccessible cardiac chambers.
abstract: BACKGROUND
  Transvenous endocardial implantation can be impossible or contraindicated in patients with inaccessible right cardiac chambers. These patients usually undergo epicardial implantation, which has been associated with frequent rising thresholds and limited lead survival. We have used the following two alternative approaches in these patients: (1) transatrial puncture and passage of pacing leads for patients with no access to the right atrium and (2) ventricular pacing from the coronary sinus or its tributaries for patients with inaccessible ventricles. METHODS. We retrospectively reviewed our experience in 9 patients who had those procedures. Five patients had pacing from the coronary sinus, and 4 by transatrial puncture.
  
  
  RESULTS
  Seven of the 9 patients had DDD pacing. Low acute pacing thresholds and satisfactory sensing levels were obtained with both approaches. One instance of high stimulation threshold (20%) occurred in the coronary sinus group and none in the transatrial puncture group. One patient in the transatrial puncture group died from unrelated causes. No malignant arrhythmias, pneumothorax, diaphragmatic pacing, or infectious complications have been observed.
  
  
  CONCLUSIONS
  These unconventional approaches are safe, relatively simple, and reliable. Although the short-term follow-up is favorable, long-term follow-up is necessary to ascertain the relative merit of these approaches.
mesh_terms: D000293:Adolescent; D000328:Adult; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria; D006327:Heart Block / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies