The effect of different pacing modes on LV global and regional longitudinal systolic strain by 2-D speckle tracking echocardiography

Background: Inspite of the fact that the life quality improved for most patients with a cardiac pacemaker implant, the pacing induced left bundle branch block pattern can result in changes of the structure, function and hemodynamic of the heart. Methods: This study was performed on 30 patients with history of dual chamber pacemaker implantation more than 6 months duration and 30 healthy volunteers as controls. Conventional and 2-D speckle tracking echocardiography were performed to evaluate the LV global and regional systolic longitudinal strain in different pacing modes. Results: Pacemaker programming from atrial sensed-ventricular paced mode (AS-VP mode) to atrial paced-ventricular paced mode (AP-VP) showed a significant decrease in global LV longitudinal systolic strain (P value <0.05). Moreover, programming to asynchronous ventricular pacing (VVI mode) demonstrated a further significant reduction of global LV LSS when compared to other pacing modes (P value <0.05). Conclusion: Permanent RV apical pacing leads to marked changes of LV systolic function. Moreover, atrial pacing and asynchronous ventricular pacing may cause more deterioration of LV global and regional systolic longitudinal strain detected by 2-D speckle tracking echocardiography.