title: Interatrial conduction measured during biventricular pacemaker implantation accurately predicts optimal paced atrioventricular intervals.
abstract: BACKGROUND
  Optimizing atrioventricular (AV) delay during biventricular (BiV) pacemaker implantation can require substantial resources. Hence, a simpler method is desirable. We hypothesized that interatrial conduction time (IACT), measured at the time of BiV device implant, could be a surrogate value for the optimal AV delay.
  
  
  OBJECTIVE
  This study determined the relationship between paced IACT and the optimal paced AV delay (PAV), as determined by echocardiography.
  
  
  METHODS
  Consecutive subjects (N = 25; age = 66 +/- 10 years; M/F: 17/8) undergoing BiV pacemaker implantation and in sinus rhythm were included. Cannulation of the coronary sinus (CS) was at the operator's discretion. A quadripolar electrophysiology catheter was inserted via the guiding sheath into the inferiolateral CS to measure left atrial depolarization. The IACT was calculated as the interval between right atrial stimulation artifact and earliest deflection on the coronary sinus catheter electrogram. Subsequently, during atrial pacing the PAV was determined using transmitral pulsed wave Doppler echocardiography (iterative method). The relationship between paced IACT and PAV was then determined.
  
  
  RESULTS
  The mean +/- SD paced IACT and PAV were 126 +/- 25 msec and 157 +/- 23 msec, respectively. There was a strong positive correlation between the paced IACT and PAV (r = 0.73, P < 0.001). The equation describing the relationship was PAV = 0.68 * (IACT + 104) msec.
  
  
  CONCLUSIONS
  The paced IACT has a strong correlation with the echo derived optimal PAV. This method may be used to program PAV intervals without need for echocardiography in patients undergoing BiV pacemaker implantation.
authors.affiliation: Lehigh Valley Hospital, Allentown, Pennsylvania, USA.
authors.forename: Vadim
authors.initials: V
authors.lastname: Levin
authors.forename: Margit
authors.initials: M
authors.lastname: Nemeth
authors.forename: Ilyas
authors.initials: I
authors.lastname: Colombowala
authors.forename: Ali
authors.initials: A
authors.lastname: Massumi
authors.forename: Abdi
authors.initials: A
authors.lastname: Rasekh
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
authors.forename: James A
authors.initials: JA
authors.lastname: Coles
authors.forename: Michael R
authors.initials: MR
authors.lastname: Ujhelyi
authors.forename: Mehdi
authors.initials: M
authors.lastname: Razavi
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000000981:diagnostic imaging*; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D019919:Prosthesis Implantation / Q000379:methods; D016896:Treatment Outcome; D014463:Ultrasonography