title: Impact of pacing site on QRS duration and its relationship to hemodynamic response in cardiac resynchronization therapy for congestive heart failure.
abstract: BACKGROUND
  Recent studies have demonstrated that left ventricular (LV) pacing site is a critical parameter in optimizing cardiac resynchronization therapy (CRT). The present study evaluates the effect of pacing from different LV locations on QRS duration (QRSd) and their relationship to acute hemodynamic response in congestive heart failure patients.
  
  
  RESULTS
  Thirty-five patients with nonischemic dilated cardiomyopathy and left bundle branch block referred for CRT device implantation were studied. Eleven predetermined LV pacing sites were systematically assessed in random order: epicardial: coronary sinus (CS); endocardial: basal and mid-cavity (septal, anterior, lateral, and inferior), apex, and the endocardial site facing the CS pacing site. For each patient QRSd and +dP/dtmax during baseline (AAI) and DDD LV pacing at 2 atrioventricular delays were compared. Response to CRT was significantly better in patients with wider baseline QRSd (≥150 milliseconds). Hemodynamic response was inversely correlated to increase of QRSd during LV pacing (short atrioventricular [AV] delay: r = 0.44, P < 0.001; long AV delay: r = 0.59, P < 0.001). Compared to baseline, LV pacing at the site of shortest QRSd significantly improved +dP/dtmax (+18 ± 25%, P < 0.001) but was not superior to other conventional strategy (lateral wall, CS pacing, and echo-guided) and was inferior to a hemodynamically guided strategy.
  
  
  CONCLUSIONS
  In our study, we have demonstrated that changes of QRSd during LV pacing correlated with acute hemodynamic response and that LV pacing location was a primary determinant of paced QRSd. Although QRSd did not predict the maximum hemodynamic response, our results confirm the link between electrical activation and hemodynamic response of the LV during CRT.
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derval
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bordachar
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Han S
authors.initials: HS
authors.lastname: Lim
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Sacher
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Ploux
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Laborderie
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Steendijk
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Deplagne
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ritter
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Garrigue
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Denis
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Haissaguerre
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Clementy
authors.affiliation: Hopital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
mesh_terms: D058406:Cardiac Resynchronization Therapy; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors
keywords: acute hemodynamic; cardiac resynchronization therapy; endocardial pacing; heart failure; implantable cardioverter defibrillator; left ventricular pacing