Right Ventricular Pacing-Induced Effects on Left Ventricular Function According to 2D Speckle-Tracking Echocardiography

Background: Permanent cardiac pacing is the most efficient treatment for conduction disorders, but it leads to asynchronous left ventricular (LV) activation, predisposing to deleterious effects on LV function and ejection fraction (EF). The predictors of LV dysfunction remain unclear, so we investigated whether strain measurements could be used to identify patients at risk of developing pacing-induced ventricular dysfunction (PIVD).Methods: The study included 50 patients > 18 years with normal LVEF (>= 55%) who underwent single-chamber pacemaker implantation for various conduction disturbances. LVEF and global longitudinal strain (GLS) measurements were assessed by 2D speckle-tracking echocardiography at baseline and then at 1-month and 12-month follow-ups. The exclusion criteria were pregnancy, diabetes mellitus, myocardial infarction, revascularization within the prior 6 months, ischemic heart disease, significant valvular disease (starting from moderate in severity), structural heart abnormalities (LV dilatation), and any other comorbidities that might cause LV remodeling.Results: At the 12-month follow-up, PIVD was detected in 14 patients (28%), 4 of whom developed pacemaker-induced cardiomyopathy (PICM). At the 1-month follow-up, GLS was significantly reduced in the 14 patients who subsequently developed PIVD at 12 months, compared with those who did not show a significant decline in EF (n=38) (GLS= -12.46 +/- 2.77 vs -16.05 +/- 2.57, respectively; P=0.001). EF was also significantly reduced in this group at the 1-month follow-up compared with those without PIVD (EF=53.57 +/- 5.05 vs 61.28 +/- 4.67, respectively; P=0.001) When the 4 patients with PICMP were excluded, only GLS at 1 month was significantly reduced compared with the baseline.Conclusions: GLS measurements shortly after pacemaker implantation provided valuable data for predicting patients who would subsequently develop PIVD.