Annelies E. van der Hulst

Relation of Left Ventricular Twist and Global Strain with Right Ventricular Dysfunction in Patients After Operative “Correction” of Tetralogy of Fallot

In patients with corrected tetralogy of Fallot (cToF), left ventricular (LV) dysfunction is closely related to right ventricular (RV) dysfunction, indicating adverse ventricular-ventricular interactions. However, the mechanism that links RV dysfunction to LV dysfunction remains unclear. In this prospective study, 32 patients with cToF and 19 controls were enrolled. With cardiac magnetic resonance imaging, biventricular ejection fractions were assessed. Using 2-dimensional speckle tracking, global and regional RV and LV strains and LV twist were assessed. To detect and characterize ventricular-ventricular interaction, the relation between global and regional RV mechanics and global and regional LV mechanics was assessed. Global RV strain, global LV strain, and LV twist were decreased in patients with cToF. Global RV strain correlated with global LV strain (r = 0.66, p <0.001) and LV twist (r = -0.72, p <0.001), indicating the presence of adverse ventricular-ventricular interaction. Furthermore, close relations were observed between apical RV strain and apical LV strain (r = 0.62, p <0.001) and apical LV rotation (r = -0.67, p <0.001). In conclusion, RV strain was significantly related to LV strain and LV twist in patients with cToF and controls. Furthermore, apical RV strain correlated with apical LV strain and apical LV rotation, indicating adverse apical ventricular-ventricular interactions.

Cardiac resynchronization therapy in paediatric and congenital heart disease patients

The number of patients with congenital heart disease (CHD) has significantly increased over the last decades. The CHD population has a high prevalence of heart failure during late follow-up and this is a major cause of mortality. Cardiac resynchronization therapy (CRT) may be a promising therapy to improve the clinical outcome of CHD and paediatric patients with heart failure. However, the CHD and paediatric population is a highly heterogeneous group with different anatomical substrates that may influence the effects of CRT. Echocardiography is the mainstay imaging modality to evaluate CHD and paediatric patients with heart failure and novel echocardiographic tools permit a comprehensive assessment of cardiac dyssynchrony that may help selecting candidates for CRT. This article reviews the role of CRT in the CHD and paediatric population with heart failure. The current inclusion criteria for CRT as well as the outcomes of different anatomical subgroups are evaluated. Finally, echocardiographic assessment of mechanical dyssynchrony in the CHD and paediatric population and its role in predicting response to CRT is comprehensively discussed.

Tetralogy of Fallot: 3D Velocity-encoded MR Imaging for Evaluation of Right Ventricular Valve Flow and Diastolic Function in Patients after Correction

PURPOSE To evaluate three-dimensional (3D) velocity-encoded (VE) magnetic resonance (MR) imaging, as compared with two-dimensional (2D) VE MR imaging, for assessment of pulmonary valve (PV) and tricuspid valve (TV) flow, with planimetry as the reference standard, and to evaluate diastolic function in patients with a corrected tetralogy of Fallot (TOF). MATERIALS AND METHODS Local institutional review board approval was obtained, and patients or their parents gave informed consent. Twenty-five patients with a corrected TOF (12 male, 13 female; mean age, 13.1 years +/- 2.7 [standard deviation]; age range, 8-18 years) and 19 control subjects (12 male, seven female; mean age, 14.1 years +/- 2.4; age range, 8-18 years) underwent planimetric MR imaging, 2D VE MR imaging, and 3D VE MR imaging for TV and PV flow evaluation. For evaluation of diastolic function, PV and TV flow were summated. Data were analyzed by using linear regression analysis, paired and unpaired t testing, and Bland-Altman plots. RESULTS Strong correlations between the 2D VE MR and 3D VE MR measurements of PV flow (for forward flow: r = 0.87, P < .01; for backward flow: r = 0.97, P < .01) were observed. With PV effective flow as a reference, 3D TV effective flow measurements were more accurate than 2D TV effective flow measurements: In patients, the mean 2D TV effective flow versus 2D PV effective flow difference was 17.6 mL +/- 11 (P < .001), and the mean 3D TV effective flow versus 3D PV effective flow difference was -1.2 mL +/- 4.7 (P = .22). Diastolic functional impairment in patients could be detected at 3D VE MR imaging diastolic assessment. CONCLUSION Three-dimensional VE MR imaging is accurate for PV flow assessment and is more accurate than 2D VE MR imaging for TV flow evaluation. Assessment of diastolic function with 3D VE MR imaging can facilitate ongoing research of diastolic dysfunction in patients with a corrected TOF.

Relationship between temporal sequence of right ventricular deformation and right ventricular performance in patients with corrected tetralogy of Fallot

Objective Right ventricular (RV) dysfunction is common in patients with corrected tetralogy of Fallot (cToF). Abnormalities in the temporal pattern of RV mechanical activation have been observed in patients with cToF, but the relationship with RV performance remains unclear. This study characterises RV performance and the temporal sequence of RV deformation in patients with cToF and healthy controls. Study design 37 patients with cToF were compared with 18 controls. Using two-dimensional speckle tracking analysis, global RV strain was assessed. In addition, time to peak strain and the time difference between RV inlet and RV outlet (RV time delay) was assessed. Main outcome measure The relation between RV performance and RV time delay was assessed with linear regression analysis. Results RV strain was reduced in patients compared with controls (−20.9±4.3% vs −30.7±3.4%, p<0.001). Time to peak strain at the RV inlet showed no differences between patients with cToF and controls (406±55 ms vs 405±67 ms, p=0.429), whereas time to peak strain at the RV outlet was significantly delayed in patients with cToF (339±75 ms vs 262±85 ms, p=0.003). Consequently, RV time delay was significantly shorter in patients with cToF than in controls (66±48 ms vs 143±53 ms, p<0.001). A close relation between RV time delay and RV strain was observed (r=−0.70, p<0.001). Conclusion In patients with cToF, RV outlet deformation is delayed, causing a reduction in RV time delay which is significantly related to impairment in RV performance.

Assessment of Intraventricular Time Differences in Healthy Children Using Two-Dimensional Speckle-Tracking Echocardiography

BACKGROUND Parameters describing intraventricular time differences are increasingly assessed in both adults and children. However, to appreciate the implications of these parameters in children, knowledge of the applicability of adult techniques in children is essential. Hence, the aim of this study was to assess the applicability of speckle-tracking strain-derived parameters in children, paying special attention to age and heart rate dependency. METHODS One hundred eighty-three healthy subjects (aged 0-19 years) were included. Left ventricular global peak strain, time to global peak strain, and parameters describing intraventricular time differences were assessed using speckle-tracking strain imaging in the apical two-chamber, three-chamber, and four-chamber views (longitudinal strain) and the parasternal short-axis view (radial and circumferential strain). Parameters describing intraventricular time differences included the standard deviation of time to peak strain and differences in time to peak strain between two specified segments. Age and heart rate dependency were evaluated using regression analysis, and intraobserver and interobserver variability were tested. RESULTS Acquisition and analysis of longitudinal six-segment time-strain curves was successful in 94.8% of subjects and radial and circumferential time-strain curves in 89.5%. No clinically significant linear relation was observed between age or heart rate and parameters describing intraventricular time differences. The coefficient of variation of time to global peak strain parameters was <10, while it was >10 for parameters describing intraventricular time differences. CONCLUSIONS The feasibility of speckle-tracking strain analysis in children is relatively good. Furthermore, no linear relation was observed between age or heart rate and parameters describing intraventricular time differences. However, the limited reproducibility of some parameters describing intraventricular time differences will confine their applicability in clinical practice.

Tissue Doppler imaging in the left ventricle and right ventricle in healthy children: normal age-related peak systolic velocities, timings, and time differences

AIMS Tissue Doppler imaging (TDI) enables assessment of velocities and timings within the left (LV) and the right (RV) ventricle with high temporal resolution. Knowledge on normal age-related values of peak systolic velocities and timings in healthy children may optimize the benefit of device-based therapies in paediatric patients with heart failure. METHODS AND RESULTS A total of 123 healthy children (from 1 month to 18 years old) underwent TDI evaluation of the RV and LV. Peak systolic velocity and time to peak systolic velocity were assessed at the basal LV lateral wall, inter-ventricular septum (IVS), RV free wall (RVFW), and at the RV outflow tract (RVOT). Intra-ventricular time differences were calculated. Regression analysis was performed to assess the age dependency of the ventricular mechanics. Median peak velocities were: LV lateral wall: 6.3 cm/s (inter-quartile range (IQR): 5.1-7.9 cm/s); IVS: 6.0 cm/s (5.4-6.7 cm/s); RVFW: 10.2 cm/s (8.9-11.3 cm/s); RVOT: 7.2 cm/s (6.0-8.2 cm/s). Timings of peak systolic velocities were: LV lateral wall: 101 ms (91-112 ms); IVS: 114 ms (100-128 ms); RVFW: 177 ms (157-194 ms); RVOT: 100 ms (88-113 ms). Timings and peak velocities significantly increased with age at both ventricles. No relevant time difference was observed within the LV, whereas a considerable time delay was observed within the RV between the RVFW and the IVS (62 ms, IQR: 45-74 ms) and between the RVFW and the RVOT (74 ms, IQR: 59-93 ms). CONCLUSION The present evaluation provides TDI-derived physiological values on normal LV and RV mechanics of healthy children. Within the LV, no relevant time difference was observed, whereas a considerable mechanical delay is observed within the healthy RV.

Mild Residual Pulmonary Stenosis in Tetralogy of Fallot Reduces Risk of Pulmonary Valve Replacement

BACKGROUND Current surgical strategies that aim at preventing pulmonary regurgitation in patients with corrected tetralogy of Fallot (cToF) may result in a certain grade of residual pulmonary stenosis (PS). The clinical implications of a postoperative residual PS in cToF patients remain unclear. Pulmonary valve replacement (PVR) is frequently needed during follow-up of cToF patients. The aim of the current study was to determine the role of residual PS in the need for PVR during follow-up in cToF patients. METHODS cToF patients were included if clinical follow-up after primary surgical correction had taken place for a minimum of 5 years. Patient characteristics, surgical factors, and postoperative factors were reviewed, with a special focus on the transpulmonic systolic gradient. Cox proportional hazards regression analysis was performed to identify predictors of PVR. RESULTS Of 171 cToF patients, 71 (41.5%) underwent PVR after 24.2 years (interquartile range, 16.8-31.6 years). Year of birth, older age at corrective operation, and patch use significantly predicted PVR during follow-up. By contrast, a mild residual PS in cToF patients (peak systolic gradient, 15-30 mm Hg) independently reduced the risk of PVR, as compared with patients without PS (hazard ratio, 0.47; p=0.02) and with moderate-to-severe PS (hazard ratio, 0.35; p=0.01). CONCLUSIONS In addition to the known risks factors for PVR, a postoperative mild residual PS reduces the risk of PVR during follow-up of cToF patients. This finding provides clinical evidence for a conservative PS relief during correction of ToF.

Corrected Tetralogy of Fallot: Comparison of Tissue Doppler Imaging and Velocity-encoded MR for Assessment of Performance and Temporal Activation of Right Ventricle

PURPOSE To compare velocity-encoded (VE) magnetic resonance (MR) imaging with tissue Doppler imaging to assess right ventricular (RV) peak systolic velocities and timing of velocities in patients with corrected tetralogy of Fallot and healthy subjects. MATERIALS AND METHODS Local institutional review board approval was obtained; patients or their parents gave informed consent. Thirty-three patients (20 male, 13 female; median age, 12 years; interquartile range [IQR], 11-15 years; age range, 8-18 years) and 19 control subjects (12 male, seven female; median age, 14 years; IQR, 12-16 years; age range, 8-18 years) underwent VE MR imaging and tissue Doppler imaging. Peak systolic velocity and time to peak systolic velocity (percentage of cardiac cycle) were assessed at the RV free wall (RVFW) and RV outflow tract (RVOT). Data were analyzed by using linear regression, paired and unpaired tests, and Bland-Altman plots. RESULTS Good correlation and agreement between the two techniques were observed. For peak systolic velocity at RVFW, r = 0.95 (mean difference, -0.4 cm/sec, P < .01), and at RVOT, r = 0.95 (mean difference, -0.4 cm/sec, P = .02). For timing at RVFW, r = 0.94 (mean difference, -0.2%, P = .44), and at RVOT, r = 0.89 (mean difference, -0.5%, P = .01). Peak systolic velocity was reduced in patients with corrected tetralogy of Fallot (at RVFW, median was 8.2 cm/sec [IQR, 6.4-9.7 cm/sec] vs 12.4 cm/sec [IQR, 10.8-13.8 cm/sec], P < .01; at RVOT, 4.7 cm/sec [IQR, 4.1-7.2 cm/sec] vs 10.2 cm/sec [IQR, 8.7-11.2 cm/sec], P < .01). The time delay between RVFW and RVOT was observed, which was significantly shorter in patients with corrected tetralogy of Fallot (median, 5.9% [IQR, 4.9%-7.4%] vs 8.4% [IQR, 6.6%-12.4%], P < .01). CONCLUSION VE MR imaging and tissue Doppler imaging enable assessment of RV systolic performance and timing of velocities at the RVFW and RVOT in patients with corrected tetralogy of Fallot. Both techniques can be used interchangeably to clinically assess velocities and timing of velocities of the RV.

Cardiac MRI in postoperative congenital heart disease patients

The survival of patients with congenital heart disease (CHD) has greatly improved over the past decades. Nevertheless, lifelong follow‐up is required in postoperative CHD patients, and noninvasive imaging plays an important role during follow‐up. Cardiac MR (CMR) imaging enables comprehensive imaging of cardiac function and anatomy, and helps to detect patients who need re‐intervention and to predict clinical outcome. Postoperative CHD patients who are frequently referred for CMR evaluation include those with coarctation of the aorta, tetralogy of Fallot, transposition of the great arteries, and single ventricle patients after the Fontan procedure. This article reviews the current clinical role of CMR in these various subgroups of postoperative CHD patients. Furthermore, an overview of novel CMR applications and their clinical value in CHD patients is provided. J. Magn. Reson. Imaging 2012;36:511–528.

Clinical application of 3D velocity-encoded magnetic resonance imaging: a new tool for the assessment of tricuspid and pulmonary valve flow and diastolic function of the right ventricle in patients after correction of Tetralogy of Fallot

Background Echocardiographic assessment of diastolic function of the right ventricle (RV) is inaccurate in the presence of pulmonary regurgitation (PR). With two-dimensional one-directional velocity-encoded MRI (2D VE-MRI), diastolic flow through the tricuspid valve (TV) and pulmonary valve (PV) can be summated, rendering time-volume curves reflecting RV relaxation. However, 2D VE-MRI of the TV is hampered by heart motion and heart rate variability. 3D VE-MRI overcomes these problems with retrospective valve tracking and the assessment of all valves during one acquisition.