Review Optimization of atrio-ventricular delay in patients with dual-chamber pacemaker Artur Klimczak a, ⁎, Michał Chudzik a , Marzenna Zielińska a , Adam S. Budzikowski b , Joanna Lewek a , Jerzy K.Wranicz a a Department of Cardiology, Medical University of Lodz, Poland b Division of Cardiovascular Medicine – EP Section, SUNY Downstate Medical Center, New York, USA abstract article info Article history: Received 1 August 2009 Accepted 18 October 2009 Available online 20 November 2009 Keywords: Atrio-ventricular optimization Pacing Impedance cardiography Echocariography Development and advances in heart pacing over the last nearly half a century allowed to save numerous lives by providing pacing support in bradycardia and complete heart block. Nevertheless, long-term follow up of patients with implanted pacemaker showed unfavorable remodeling of the heart, both from hemodynamic as well as electrical standpoint. The optimal programmed pacemaker setting, apart from the optimal place for ventricular stimulation, is essential to obtain the best hemodynamic and the clinical after-effects of the stimulation of the heart and to minimize potential unfavorable effects. In patients with dual-chamber pacemaker (DDD) the correct function of the left ventricle of the heart depends mainly on the electric delays between the stimulated chambers. Atrio-ventricular delay (AVD) during dual-chamber pacing influences left ventricle contraction function through preload modulation. Improperly programmed AVD in the DDD pacemaker can have unfavorable hemodynamic results. Various methods have been developed during last few decades (right heart catheterization, ventriculography, peak endocardial acceleration, echocardiography, and impedance cardiography), however only echocardiography and reocardiography are currently in general use. There should be noticed too, that also the application of special algorithms present in modern pacemakers allowing for dynamic changes of the time of the delay represents certain alternative to individual AVD optimization. © 2009 Elsevier Ireland Ltd. All rights reserved. Development and advances in heart pacing over the last nearly half a century allowed to save numerous lives by providing pacing support in bradycardia and complete heart block. Nevertheless, long- term follow up of patients with implanted pacemaker showed unfavorable remodeling of the heart, both from hemodynamic as well as electrical standpoint [1]. Therefore, efforts have been made to establish the method of stimulation of the right ventricle that would be the most similar to depolarization observed in case of physiological impulses conduction via native conduction system in an expectation that these complications would be avoided. Although large trial data are not available, smaller studies support the notion that the right ventricle should be stimulated from outflow tract; to avoid unfavor- able long-term hemodynamic and electric after-effects [2]. The optimal programmed pacemaker setting, apart from the optimal place for ventricular stimulation, is essential to obtain the best hemodynamic and the clinical after-effects of the stimulation of the heart and to minimize potential unfavorable effects. In patients with dual-chamber pacemaker (DDD) the correct function of the left ventricle of the heart depends mainly on the electric delays between the stimulated chambers. Timing of the optimal atrio-ventricular conduction differs among patients and require individual setting [3,4]. Atrio-ventricular delay (AVD) during dual-chamber pacing influences left ventricle contraction function through preload modulation [5]. Improperly programmed AVD in the DDD pacemaker can have unfavorable hemodynamic results [6]. The aim of this manuscript is to review the clinical and technical aspects of AVD optimization and existing methods to define the optimal AVD in patients with DDD pacemaker. 1. Atrio-ventricular delay The AVD is this the time from the beginning of paced or sensed atrial activity to the impulse of ventricle stimulation or sensed ventricular activity (Fig. 1). Modern DDD pacemakers allow wide range of programming of AVD and AVD-related algorithms. Sensing of the intrinsic ventricular depolarization before the end of programmed AVD results in inhibition of ventricular pacing. Proper setting of AVD allows to achieve electromechanical synchrony of atrial and ventricular contractions and the individual setting of AVD in patients with atrio-ventricular block can have the beneficial effects not only on the contractile function of the heart, but also on long-term prognosis [7]. The optimization of AVD has the special meaning particularly in patients with the left ventricle hypertrophy and the predominant diastolic dysfunction of the left International Journal of Cardiology 141 (2010) 222–226 ⁎ Corresponding author. Tel./fax: +48426364471. E-mail address: artur.klimczak@gmail.com (A. Klimczak). 0167-5273/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2009.10.021 Contents lists available at ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard