Value of Speckle Tracking Echocardiography as a Predictor of the Deleterious Effect of Right Ventricular Pacing on Left Ventricular Function

Background: Pacemaker-induced cardiomyopathy (PICM) is reported in different articles but with variable incidence. Aim: The aim of the study is to determine the validity of speckle tracking echocardiography as a predictor of the deleterious effect of right ventricular (RV) pacing on left ventricular (LV) function, using two-dimensional guided global and segmental longitudinal strain. Materials and Methods: Fifty patients with conventional indications for permanent pacemaker implantation were studied; they were classified to Group A (37 = 74%) patients who didn't show a significant reduction of ejection fraction (EF) (>10%) and Group B (13 = 26%) represent patients who showed a significant reduction of EF. Group C constituted 25 healthy persons (control group). We defined PICM when EF is reduced >10%. Results: The incidence of pacemaker-induced ventricular dysfunction was 26%. Statistical analysis revealed that left atrial volume index (LAVI), global longitudinal strain (GLS), native-QRS duration, and ischemic heart disease were significant predictors of reduction of LV function, however, on multivariate regression analysis, only the LAVI and GLS were independent predictors of reduction of LVEF after permanent pacing. Conclusions: Speckle tracking echocardiography is a new, unique and evolving tool to assess the myocardial deformation which can detect LV systolic dysfunction much earlier than can be reflected in LVEF. The importance of defining predictors is to predict whom patient will be at risk for the deleterious effect of RV pacing on LV function, and who will need observation with possible upgrading to biventricular pacing.