Right ventricular remodeling due to pulmonary regurgitation is associated with reduced left ventricular free wall strain in surgically repaired tetralogy of fallot.
BACKGROUND
The aim of the present study was to assess the impact of pulmonary regurgitation (PR) and right ventricle (RV) volume on left ventricle (LV) longitudinal strain (LS) in patients with surgically repaired tetralogy of Fallot (r-TOF).


METHODS AND RESULTS
The study subjects were 32 adolescent asymptomatic r-TOF subjects and 30 adolescent healthy controls. Two-dimensional (2-D) and 3-dimensional (3-D) echocardiography were performed in all subjects using Vivid E9 (GE Healthcare). On 3-D analysis, LV and RV volumes were measured using 4D auto LVEF and TomTec RV analysis. PR fraction (PRF) was calculated by the volumetric method (PRF=[RV stroke volume-LV stroke volume]/RV stroke volume). LV-LS was assessed on 2-D speckle tracking echocardiography, and "free wall LS" represented the average of 3 lateral segments. Although RVEF and LVEF were not different between the 2 groups, free wall LS (-17.1 ± 3.2%) was reduced significantly in the r-TOF group compared to the control (-20.5 ± 4.9%, P=0.008), and correlated with the RV variables RVEDVI, RV/LV EDVI ratio and PRF. On multivariate stepwise linear regression analysis, RVEDVI was the only risk factor for the reduction of free wall LS (P=0.004).


CONCLUSIONS
Free wall LS was significantly reduced despite preserved LVEF. The severity of LS reduction was correlated with RV dilation even in asymptomatic r-TOF patients.