title: Long-term follow-up of atrioventricular delay optimization in patients with biventricular pacing.
abstract: BACKGROUND
  Atrioventricular (AV) delay optimization may be important in patients with biventricular pacing and the optimal AV delay can be predicted using Doppler echocardiography and the formula: optimal AV delay = AV delay-the interval between the end of A wave and complete closure of the mitral valve when the AV delay is set at slightly prolonged AV delay.
  
  
  RESULTS
  In the present study the efficacy of this method was evaluated in 5 patients (67.4+/-8.0 (SD) years old) with biventricular pacing. Cardiac output (CO) and diastolic filling time were measured by Doppler echocardiography. When the AV delay was set at the predicted optimal AV delay -25 ms, the predicted optimal AV delay (133+/-66 ms) and predicted optimal AV delay + 25 ms, the respective CO were 4.5+/-0.9, 5.3+/-1.0, 4.8+/-1.0 L/min (p<0.05, ANOVA) and the diastolic filling times were 364 +/-100, 373+/-105, 335+/-84 ms (p<0.05, ANOVA). Congestive heart failure improved from New York Heart Association class 3.6+/-0.5 to 1.4+/-0.5 (p<0.001).
  
  
  CONCLUSIONS
  AV delay optimization is important in patients with biventricular pacing and can be easily achieved by the new method.
authors.affiliation: Second Department of Internal Medicine, Yokohama City University Hospital, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Inoue
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sumita
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Kohei
authors.initials: K
authors.lastname: Matsushita
authors.forename: Katsumi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohkusu
authors.forename: Minoru
authors.initials: M
authors.lastname: Taima
authors.forename: Masami
authors.initials: M
authors.lastname: Kosuge
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Uchino
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kimura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Umemura
mesh_terms: D000368:Aged; D001283:Atrioventricular Node / Q000502:physiology*; D002302:Cardiac Output; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018619:Echocardiography, Doppler, Pulsed; D005500:Follow-Up Studies; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D008722:Methods; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology