Detection of left ventricular asynchrony in patients with right bundle branch block after repair of tetralogy of Fallot using tissue-Doppler imaging-derived strain

Abstract

Objectives: We aimed to investigate whether patients after tetralogy of Fallot (TOF) repair with right bundle branch block have left ventricular (LV) asynchrony and to assess the influence of ventricular asynchrony on regional and global LV function.

Background: Patients after TOF repair usually have right bundle branch block. However, no data regarding LV asynchrony in this group are available.

Methods: Twenty-five patients after TOF repair and 25 age-matched healthy control subjects were studied. The regional myocardial deformation of the interventricular septum (IVS) and the LV lateral wall were examined using tissue-Doppler-derived strain. The time interval between the onset of QRS complex and the peak strain was measured for each wall. According to the difference between LV and septum time intervals among the normal subjects, a normal range (mean +/- 2 SD) was plotted, and TOF patients in whom the difference was beyond the normal range were considered to have LV asynchrony. The Tei index was used to assess global LV function.

Results: Thirteen (52%) of the examined patients after TOF repair had LV asynchrony. Patients after TOF repair with LV asynchrony had a significantly reduced regional septal systolic strain (p < 0.001) and significantly elevated Tei index (p < 0.001) compared with those without.

Conclusions: Left ventricular asynchrony may exist in patients after TOF repair with right bundle branch block. This LV asynchrony is associated with a reduction of both regional and global LV function.