Abstract 9430: Right Ventricular Apical and Free Wall Pacing, but Not Ventricular Septal Pacing Leads to Left Ventricular Reverse Rotation
Background: Although left ventricular (LV) twisting has been recognized to play an important role in LV function, the impact of right ventricular (RV) pacing on LV twisting including rotational abnormality has not been fully understood. We investigated the influence of the pacing site on the rotational abnormality in patients underwent pacemaker implantation.
Methods and Results: We evaluated 21 patients who underwent permanent pacemaker implantation for sick sinus syndrome or atrioventricular block (age 79 years) with preserved systolic function. According to RV pacing site, we divided our patients into septal pacing group (n=10) and non-septal (free wall or apex) pacing group (n=11). Rotation in the apical LV was evaluated using speckle tracking image in echocardiogram and the clockwise rotation of the apical wall or/and the counterclockwise rotation of the basal wall were defined as reverse rotation. We assessed LV rotational abnormality, under own beats or/and RV pacing rhythm.
Results: During own beats, only one patient (1/21= 5%) with incomplete right branch block and atrial flutter demonstrated reverse rotation. In contrast, during RV pacing rhythm, 9 patients (9/21=43%) exhibited reverse rotation, in whom there were 8 patients in non-septal pacing group and 1 patient in septal pacing group. Reverse rotation was observed more in non-septal pacing group than in septal pacing group.
Conclusions: RV apical or free wall pacing could induce the reverse rotation of the LV wall while RV septal pacing preserved LV rotation.
- © 2011 by American Heart Association, Inc.