Biventricular Function is Impaired in Right Ventricular Septal Pacing-A Prospective Study Using Myocardial Strain Imaging.

Abstract

Left ventricular (LV) dysfunction is known to occur after right ventricular (RV) pacing; the effect on RV function is less well studied. The aim of this study was to assess the impact of RV mid-septal pacing upon RV function using the novel parameters of speckle-tracking derived RV global longitudinal strain (RV GLS) and RV free wall strain (RV FWS), as well as the conventional parameters RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and tricuspid annular systolic velocity (RV S'). Thirty-two (32) consecutive patients with normal baseline LV and RV function requiring permanent pacemaker insertion were prospectively recruited. Echocardiography was performed prior to implantation, at 1 day, 1 month and 1 year after implantation, with 29 patients completing follow-up. After 1 year, three patients (10%) with otherwise normal RV parameters developed abnormal RV strain patterns. Compared to 1 day after implantation, at 1 year significant reductions were observed in mean RV GLS (-24.8 to -21.8%) RV S' (15.1 to 12.2 cm/s), TAPSE (24.2 to 21.9 mm), RV GLS (-24.8 to -21.8%), left ventricular ejection fraction (LVEF) (66.0 to 57.9%), LV GLS (-19.9 to 17.0), all p<0.01. There was a non-significant reduction for RV FWS (-29.0 to -26.7%, p=0.06) and there was no change in RV FAC (49.1 to 46.9%, p=0.24). We report abnormalities of RV strain developing 1 year after pacemaker insertion. Measurement of myocardial strain is emerging as an additional method to detect patients at risk of RV dysfunction in those who have undergone pacemaker implantation.