title: Left ventricular pacing by automatic capture verification.
abstract: OBJECTIVE
  To investigate the feasibility of transvenous left ventricular (LV) pacing by autocapture at long term. A reliable measurement of LV evoked response (ER) is the pivotal requirement for beat-to-beat detection of ventricular capture and automatic output adjustment.
  
  
  RESULTS
  Seven patients with accepted class I indication to permanent cardiac pacing received a DDDR pacemaker with automatic output adjustment based on beat-to-beat capture verification (Insignia Ultra 1290, Guidant), whose ventricular port was connected to a LV lead placed in a branch of the coronary sinus. The device allows LV threshold trending, performing a threshold test every 21 h, and diagnoses acute and non-acute issues of ER detection during follow up. Average follow up after implantation was 34 +/- 6 months (range 28-45, median 34). Left ventricular pacing threshold showed an increase from implantation (1.2 +/- 0.4 V at 0.4 ms) that peaked at week 4 (1.6 +/- 0.7 V at 0.4 ms), and returned to baseline (1.1 +/- 0.5 at 0.4 ms) by the end of the 7th week. Autocapture performance at long term, as assessed by the trend of LV threshold and of ER diagnostic issues, did not show any pitfall.
  
  
  CONCLUSIONS
  Our observations support the feasibility and safety of capture verification during LV pacing alone. A possible application of this pacing technology could be biventricular stimulation.
authors.affiliation: Institute of Cardiology, University of Bologna, Via Massarenti 9, 40138 Bologna, Italy. mauro.biffi@aosp.bo.it
authors.forename: Mauro
authors.initials: M
authors.lastname: Biffi
authors.forename: Matteo
authors.initials: M
authors.lastname: Bertini
authors.forename: Matteo
authors.initials: M
authors.lastname: Ziacchi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods*; D004599:Electric Stimulation Therapy; D004562:Electrocardiography; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial