RESUMEN
BACKGROUND: We aimed to assess the existence of myocardial dysfunction and intra-univentricular diastolic asynchrony in patients after Fontan operation. METHODS: Twenty patients after Fontan procedure and 30 age-matched controls were included in the study. The global function of the univentricular heart was analyzed by the Tei index. Regional myocardial velocities and strain of the univentricular heart including the rudimentary right ventricle (RV) were quantified by tissue Doppler imaging. Intra-univentricular or intra left ventricular (LV) diastolic delay was measured from the difference of diastolic intervals (time to peak early diastolic velocity), measured at LV lateral wall and the rudimental RV wall in patients, or LV lateral wall and the ventricular septum in controls. RESULTS: Compared to the control group, patients after Fontan operation had significantly elevated Tei index (0.24 ± 0.02 vs. 0.41 ± 0.1, p < 0.001). On the other hand, the regional myocardial velocities and strains of the univentricular heart including the rudimentary RV were significantly reduced (p < 0.001). Among patients, there was a significant correlation between the Tei index of the univentricular ventricle and rudimentary RV strain (r = -0.66, p = 0.01). The heart rate-corrected intra-univentricular diastolic delay was significantly prolonged among patients when compared to the intra-LV diastolic delay in controls (0.01 ± 0.9 vs. 1 ± 1.1, p = 0.005). CONCLUSIONS: Myocardial dysfunctions and intra-univentricular diastolic asynchrony of the univentricular heart in patients after Fontan procedure are evident. The rudimentary RV in patients after Fontan procedure plays an important role in the determination of the global function of the univentricular heart.
RESUMEN
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.
