Longitudinal Systolic Left Ventricular-Right Ventricular Interaction in Pediatric and Young Adult Patients with TOF: A Magnetic Resonance Imaging and M-Mode Echocardiography Study

Purpose: The aim of this study was to evaluate longitudinal systolic left ventricular (LV)-right ventricular (RV) interaction in 146 pediatric and young adult patients with operated tetralogy of Fallot (TOF).

Methods: We determined measures of longitudinal M-mode echocardiography (i.e., tricuspid annular plane systolic excursion [TAPSE]; the mitral annular plane systolic excursion [MAPSE]) compared with longitudinal function parameters using magnetic resonance imaging (MRI). M-Mode data were compared with established normal z-score values.

Results: We found a good correlation between MAPSE and LVEF values (r= 0.788; p < 0.001). Correlations between MRI derived MAPSE and M-mode guided MAPSE (r= 0.879, p < 0.001), and between MRI derived TAPSE and M-mode guided TAPSE were significant (r= 0.780, p < 0.001). Although the LVEF was normal in patients with a normal RVEF, the LVEF was decreased in patients with significantly reduced RVEF. Patients with a significantly dilated RV showed a significantly reduced mean MAPSE of 1.30 ± 0.26 cm. LV longitudinal function decreases below –2 SD of normal MAPSE z-score values after a mean of 22 postoperative years.

Conclusions: Our data confirm progressive adverse RV-LV interaction in the long-term follow-up of TOF. We show that simple M-mode measurement of the longitudinal LV function (i.e., MAPSE) is a sufficient surrogate for estimation of LVEF. In case of poor sonographic windows, MAPSE measurement is helpful for LV systolic function assessment.