Assessment of interventricular and right-intraventricular dyssynchrony in patients with surgically repaired tetralogy of Fallot by two-dimensional speckle tracking.

AIMS: We aimed to assess interventricular and right-intraventricular dyssynchrony in patients after tetralogy of Fallot (TOF) repair by two-dimensional (2D) speckle tracking and to identify factors associated with dyssynchrony. METHODS AND RESULTS: Forty-two patients after TOF repair with a mean age of 19.8 years and 42 age-matched healthy controls were studied. Longitudinal myocardial deformation (strain) and time-to-peak intervals were assessed by 2D speckle tracking and tissue Doppler imaging (TDI) in an apical four-chamber view. Dyssynchrony was defined as delay above 3 standard deviations of mean values in the control group. Magnetic resonance imaging (MRI) was performed for evaluation of ventricular function. Using 2D speckle tracking, 22 patients (52%) showed interventricular dyssynchrony and 16 (38%) had right-intraventricular dyssynchrony. The interventricular delay correlated significantly with right ventricular (RV) strain (r = 0.687, P < 0.001), RV systolic pressure (r = 0.535, P = 0.001), QRS duration (r = 0.466, P = 0.002), RV end-diastolic (r = 0.377, P = 0.018), and RV end-systolic volumes (r = 0.452, P = 0.004) as well as RV ejection fraction (r = -0.378, P = 0.018). Similarly, the right-intraventricular delay correlated significantly with RV strain (r = 0.534, P < 0.001), QRS duration (r = 0.428, P = 0.005), RV end-systolic volume (r = 0.34, P = 0.038), and RV systolic pressure (r = 0.413, P = 0.015). In multivariate regression analysis, reduced RV strain and prolonged QRS duration remained the main determinant factors predicting dyssynchrony. Moreover, 2D speckle tracking and TDI showed a significant correlation in the assessment of the interventricular (r = 0.738, P < 0.001) and right-intraventricular delay (r = 0.747, P < 0.001). CONCLUSION: Interventricular and right-intraventricular dyssynchrony are detectable in patients after TOF repair by 2D speckle tracking. Reduced RV myocardial deformation and QRS prolongation are the main factors associated with the observed dyssynchrony.

Impact of gender and age on cardiovascular function late after repair of tetralogy of Fallot: percentiles based on cardiac magnetic resonance.

BACKGROUND: The impact of gender and age on cardiac function by cardiac magnetic resonance (CMR) in repaired tetralogy of Fallot (TOF) is unknown, which limits the value of currently discussed volumetric thresholds and the accuracy of individual follow-up. METHODS AND RESULTS: In a nationwide, prospective, 14-center study, 407 consecutive patients with repaired TOF (age, 17.9±8.3 years; range, 8-59 years; 226 male patients) underwent standardized CMR ventricular volumetry and flow quantification (pulmonary artery/ascending aorta). There were no sex differences for age at TOF repair, type of repair, number of prior repair palliations or reinterventions after repair, pulmonary regurgitation fraction, and maximal gradient across the right ventricular outflow tract. Biventricular volumes and mass (indexed to body surface area), available in 380 of 407 patients, respectively, were higher in male patients (P<0.003), but biventricular ejection fraction was higher in female patients (P<0.012). As opposed to reported data of healthy populations, sex-specific reference percentiles computed for an age range of 8 to 40 years (lambda-mu-sigma method) demonstrated (1) an increase of end-diastolic and end-systolic left ventricular volumes, particularly in female patients; (2) an increase of end-systolic right ventricular volumes in both sexes; and (3) a decrease of biventricular ejection fraction in male patients, whereas in female patients, only right ventricular ejection fraction decreased. CONCLUSIONS: Significant gender differences of biventricular volumes, function, and mass by CMR exist late after repair of TOF, suggesting that age and gender cannot be ignored when discussing thresholds. Gender-specific percentiles may present a more relevant framework of reference for an individual patient at a given age and suggest a gradual decline of biventricular systolic function over time.

Right ventricular function in grown-up patients after correction of congenital right heart disease.

AIMS: We investigated whether a correlation exists between biomarkers of the neurohumoral system and clinical markers in grown-up patients with congenital heart disease (GUCH) and right ventricular function. METHODS AND RESULTS: Prospective, cross-sectional, multicenter study of 104 GUCH patients (median) 16 years (range 6-43 years) after corrective surgery with RV pressure and/or volume overload and 54 healthy controls. Clinical, functional, and laboratory parameters were assessed. Natriuretic peptide levels were significantly increased in GUCH patients (NTproBNP 101 vs. 25 pg/ml, p < 0.001), but we observed no differences in norepinephrine, aldosterone, angiotensin II and Endothelin-1 levels. NTproBNP correlated significantly with clinical markers such as NYHA classification, prolonged QRS duration and reduced exercise capacity (VO(2) peak) (all p < 0.001), as well as self-reported quality of life (p < 0.001). MRI and echocardiography derived RV volumes were elevated and ejection fraction reduced in the patients (both p < 0.001). Tissue Doppler parameter showed significantly restricted ventricular longitudinal systolic function (longitudinal tricuspid valve movement, 1.7 vs. 2.3 cm, p < 0.001), suggesting stiffness and reduced RV compliance. CONCLUSION: In conclusion, grown-up patients with congenital right heart disease NTproBNP correlates well with various clinical markers of RV failure, such as prolongation of QRS duration, exercise capacity, echocardiography and MRI parameters, and quality of life.

The quantification of dipyridamole induced changes in regional deformation in normal, stunned or infarcted myocardium as measured by strain and strain rate: an experimental study.

UNLABELLED: Strain rate imaging (SRI) during dobutamine stress-echocardiography (DSE) has been shown to differentiate between ischemic substrates based on the segmental response. Dipyridamole stress echo (DIPSE) is currently used as an alternative to DSE in detecting coronary artery disease. The aim of this study was: (a) to determine the normal response in peak-systolic myocardial strain (S) and strain-rate (SR) during DIPSE and (b) to compare the S and SR responses of DSE and DIPSE in the same chronically ischemic/infarcted segments in the setting of single vessel disease. METHODS: The deformation response to DIPSE was studied in 7 normal pigs and in an additional 18 pigs, with a spectrum of ischemic substrates. S and SR data were extracted from a posterior wall "at risk" segment at baseline and during both DSE and DIPSE. The animals were divided into different ischemic substrate (stunning, non-transmural and transmural infarction), based on the DSE response as previously suggested. RESULTS: In normal myocardium, dipyridamole induced no changes in regional systolic deformation neither during nor after the infusion. Furthermore there was no detectable response in S and SR in segments with either a non-transmural or a transmural infarction. However, in myocardial segments with a DSE "stunning response", both end systolic S and peak-systolic SR tended to "normalize" at peak dipyridamole dose. CONCLUSIONS: These results suggest that dipyridamole does not induce changes in regional deformation in normal or (partially) infarcted myocardium. Only in stunned myocardium (in the setting of single-vessel disease), dipyridamole tends to normalize deformation.

Heart rate effects on strain and strain rate in healthy children.

Based on myocardial Doppler echocardiography, regional strain (S) and strain rate (SR) can be evaluated as regional parameters of ventricular function. The use of these techniques in clinical pediatric cardiology remains a challenge. This study establishes reference values for S and SR in both systole and diastole in healthy children over a large age range and evaluates the potential relationships of demographic and echocardiographic parameters on S and SR, and, in particular, assesses the clinical effect of heart rate on S and SR in healthy children. It is shown that heart rate changes in children during growth have an important impact on both systolic and diastolic myocardial S and late diastolic SR. Therefore, to evaluate regional myocardial function in children, heart rate at rest should be considered an important factor.