title: The effect of different atrioventricular delays on left atrium and left atrial appendage function in patients with DDD pacemaker.
abstract: BACKGROUND
  Although it has been known that optimization of atrioventricular delay (AVD) has favorable effect on the left ventricular functions in patients with DDD pacemaker, the effect of different AVDs on left atrium (LA) and left atrial appendage (LAA) functions has not been exactly evaluated. The aim of the present study was to assess the effect of different AVDs on LA and LAA functions in DDD pacemaker implanted patients with atrioventricular block.
  
  
  METHODS
  Forty-eight patients with DDD pacemaker were enrolled into the study. Patients were divided into two groups according to the echocardiographic diastolic function: Group I (normal diastolic function) and Group II (diastolic dysfunction). LAA emptying velocity on pulsed wave Doppler and LAA late systolic wave velocity by using tissue Doppler were recorded. Patients were paced for five successive continuous pacing periods of 10 minutes duration using five selective AVDs (80-250 ms).
  
  
  RESULTS
  Significant effect on LA and LAA functions has not been observed by the setting of AVD in Group I. However, when the AVD was gradually shortened form 150 ms to 80 ms, LA and LAA functions gradually decreased in Group II patients. When AVD increased to 200 ms, LA and LAA functions were improved. Further increase in AVD resulted in decreased LA and LAA functions.
  
  
  CONCLUSIONS
  Setting of AVD has not significant effect on the LA and LAA functions in patients with normal diastolic function, but moderate prolongation of AVD in physiological limits improved LA and LAA functions in DDD pacemaker implanted patients with diastolic dysfunction.
authors: Department of Cardiology, Faculty of Medicine, Çukurova University Adana, Turkey.
authors: Mehmet
authors: M
authors: Kanadaşı
authors: Murat
authors: M
authors: Caylı
authors: Durmuş Yıldıray
authors: DY
authors: Sahin
authors: Ömer
authors: Ö
authors: Sen
authors: Mevlüt
authors: M
authors: Koç
authors: Ayhan
authors: A
authors: Usal
authors: Mustafa Kemal
authors: MK
authors: Batur
authors: Mustafa
authors: M
authors: Demirtaş
mesh_terms: D020517:Atrial Appendage / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D054537:Atrioventricular Block / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control