title: Hemodynamic effects of atrial septal pacing in cardiac resynchronization therapy patients.
abstract: BACKGROUND
  Spontaneous or pacing-induced interatrial conduction delay may affect the outcome of heart failure patients treated with cardiac resynchronization therapy (CRT). The objective of this study was to evaluate the impact of the atrial pacing site (right atrial appendage, RAA; and low interatrial septum, LIS) during biventricular (BV) pacing on the left ventricular (LV) systolic function in candidates for CRT.
  
  
  RESULTS
  Fifteen heart failure patients with left bundle branch block and LV ejection fraction < or =35% were enrolled. Electrodes were placed at the RAA, LIS, right ventricular apex, and LV free wall. A DDD protocol was tested, which consisted of 50 beats in AAI mode from the RAA followed by 50 beats in BV DDD mode with atrial pacing at the RAA (DDD_RAA) or at the LIS (DDD_LIS) at four AV delays. The average (+/-SD)%LV+dP/dtmax increase during DDD_RAA and DDD_LIS pacing with respect to baseline was 24 +/- 16% and 21 +/- 15%, respectively (P < 0.01), and average percentage change in aortic pulse pressure during DDD_RAA and DDD_LIS with respect to baseline (%PP) was 13 +/- 8% and 13 +/- 7% (ns).
  
  
  CONCLUSIONS
  Our results show a significant hemodynamic improvement with both DDD_RAA and DDD_LIS biventricular pacing compared to AAI pacing. However DDD_LIS pacing was not superior to DDD_RAA pacing in acute hemodynamic responses.
authors.affiliation: Department of Cardiology, Ospedale Umberto I, Mestre-Venezia, Italy. francesco.dipede@ulss12.ve.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Di Pede
authors.forename: Gianni
authors.initials: G
authors.lastname: Gasparini
authors.forename: Bruno
authors.initials: B
authors.lastname: De Piccoli
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Yu
authors.forename: Francisca
authors.initials: F
authors.lastname: Cuesta
authors.forename: Antonio
authors.initials: A
authors.lastname: Raviele
mesh_terms: D000208:Acute Disease; D000368:Aged; D002037:Bundle-Branch Block / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D002311:Cardiomyopathy, Dilated / Q000628:therapy*; D004566:Electrodes; D004594:Electrophysiology; D005260:Female; D006325:Heart Atria; D006329:Heart Conduction System / Q000503:physiopathology*; D006346:Heart Septum; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume; D013997:Time Factors