Image quality and radiation doses of volumetric 320-row computed tomography angiography with prospective electrocardiogram-gating in the assessment of coronary arteries in neonates and infants.

BACKGROUND: Diagnostic imaging of coronary arteries is required in neonates and infants suspected of congenital or acquired coronary artery anomalies and in pre- and postoperative assessment of complex congenital heart diseases (CHD). AIM: Our study aimed to evaluate the image quality of volumetric 320-row computed tomography angiography (CTA) with prospective electrocardiogram (ECG)-gating for coronary arteries in neonates and infants with heart diseases, analyze factors influencing image quality and assess a radiation dose related to the procedure. METHODS: The study included 110 CTA performed in neonates and infants with CHD. RESULTS: CTA was performed in 37 girls and 73 boys at a median (interquartile range [IQR]) age of 3.0 (0.5-5.0) months, median (IQR) body weight of 5 (3.66-6.5) kg, and median heart rate (HR) of 133 (92-150) beats per minute. The orifices of the left coronary artery were visible in 100% of CTA, the orifices of the right coronary arteries were visible in 96%, whereas all coronary segments were assessable in 45% of CTA. Patients with non-diagnostic segments were significantly younger, median (IQR) age of 2.0 (0.21-5.00) months, had lower body weight of 4.6 (3.45-6.07) kg and faster HR of 136.5 (120-150) beats per minute (P <0.05) than patients with diagnostic image quality in all segments (4.0, 2-6 months, 6.0, 4.2-7 kg, and 130; 110-150 beats per minute, respectively; P <0.05). CONCLUSIONS: CTA performed with volumetric 320-row prospective ECG-gating allows for good visibility of the coronary arteries with an acceptable radiation dose. Children aged >15 days, with body weight >4.85 kg and HR <130 beats per minute are good candidates for excellent quality non-invasive CTA of all segments of coronary arteries.

Assessment of the physical performance in children with asymptomatic pre-excitation.

AIMS: Pre-excitation syndrome can lead to recurrent supraventricular tachycardias (SVTs) and carries a risk of sudden cardiac death (SCD). However, an underestimated consequence of antegrade conduction through an accessory pathway is fusion of intrinsic and accessory conduction that causes asynchronous activation and myocardial contraction that could be a cause for cardiac dysfunction and dilation. It is not known to what extent pre-excitation affects myocardial and physical performance in those patients. The aim of the study was to assess to what degree ventricular pre-excitation affects physical performance in children, using cardio-pulmonary exercise testing (CPET). METHODS AND RESULTS: The study group consisted of 30 asymptomatic children, aged 8-17 years, with pre-excitation and no history or documentation of SVT compared to 31 healthy controls matched according to sex and age. All patients underwent routine cardiology assessment and then CPET. Echocardiography showed there were no differences in the left ventricular size and function between the study and control group. During the CPET both, patients and controls achieved maximal effort. Patients in the study group showed significantly lower values of VO2max and anaerobic threshold when compared to controls. The most affected subgroup was patients with persistent pre-excitation throughout the exercise. CONCLUSIONS: Physical performance is affected in children with pre-excitation. This effect is stronger in patients with persistent delta wave observed throughout the exercise.

Usefulness of three-dimensional echocardiography for assessment of left and right ventricular volumes in children, verified by cardiac magnetic resonance. Can we overcome the discrepancy?

INTRODUCTION: The role of three-dimensional echocardiography (3D-ECHO) chamber quantification in children is still underestimated. MATERIAL AND METHODS: In 43 children 3D-ECHO measurements of end-diastolic (EDV) and end-systolic ventricular volumes (ESV) were compared to cardiac magnetic resonance (CMR) using Bland-Altman analysis and linear regression. The values of left and right ventricular volumes calculated in 3D-ECHO were compared with each other and verified by CMR. RESULTS: The values of LV-EDV and LV-ESV measured in 3D-ECHO showed highly significant correlations with CMR (for LV-EDV r = 0.892, p < 0.00001; for LV-ESV r = 0.896, p < 0.00001). In the case of the right ventricle the correlation of 3D-ECHO results with CMR was still high (RV-EDV r = 0.848, p < 0.00001, RV-ESV r = 0.914, p < 0.00001), although mean RV-EDV and RV-ESV in 3D-ECHO were underestimated compared to CMR (by 38% for RV-EDV and 45% for RV-ESV). Correction of 3D-ECHO results using the coefficient of 1.38 and 1.45 for RV-EDV and RV-ESV, respectively, significantly improved the consistency of the results with CMR. 3D-ECHO offered lower mean values of right ventricular volumes compared to the left ventricle. The discrepancy was again reduced by the calculated coefficients. CONCLUSIONS: 3D-ECHO is a valuable tool for assessment of left ventricular volume, which strongly correlates and agrees with CMR. The right ventricular volumes calculated in 3D-ECHO tend to be significantly underestimated in comparison to CMR and corresponding left ventricular volumes obtained from 3D-ECHO. The use of coefficients developed by the study improves the consistency of right ventricular volumes measured by 3D-ECHO with results obtained by CMR and reduces the volumetric discrepancy between ventricles in 3D-ECHO.

Usefulness of three-dimensional echocardiography for the assessment of ventricular function in children: Comparison with cardiac magnetic resonance, with a focus on patients with arrhythmia.

BACKGROUND: Focusing on patients with arrhythmia, the aims of this study was to assess ventricular function in children using three-dimensional echocardiography (3D-ECHO) and to compare the results to those obtained with cardiac magnetic resonance (CMR). METHODS: The study group consisted of 43 children in whom 3D-ECHO and CMR were performed. Twenty-five patients had a ventricular arrhythmia, 7 left ventricular cardiomyopathies, 9 proved to be healthy. In all children, 3D-ECHO (offline analysis) was used to assess ventricular ejection fraction (EF). The results were compared to CMR using the Bland-Altman analysis and linear regression. The Student paired T-test was used to compare of means between both modalities. RESULTS: The relation between the results derived from both methods is linear (for left ventricle: estimated slope = 1.031, p < 0.0001, R-squared = 0.998; for right ventricle: estimated slope = 0.993, p < 0.0001, R-squared = 0.998). In spite of minimal mean differences between results for both ventricles and narrow 95% confidence intervals, the paired t-test proved those differences not to be significant (p > 0.05) for the right ventricle but statistically significant (p < 0.05) for the left ventricle, for which the left ventricular EF calculated in 3D-ECHO was systematically underestimated with a mean difference of -1.8% ± 2.6% (p < 0.0001). CONCLUSIONS: Three-dimensional echocardiography assessment of both left and right ventricular EF in children showed high significant correlation and agreement with CMR. 3D-ECHO could be a valuable tool in follow-up of children with arrhythmic disorders requiring regular assessment of ventricular function.

Three-dimensional echocardiography in the assessment of ventricular function in children: pros, cons, and hopes.

The accurate assessment of ventricular function is crucial in paediatric cardiology because its results affect the diagnosis and clinical management. Children with cardiovascular problems require frequent evaluation of ventricular function parameters; therefore, three-dimensional echocardiography may be the perfect modality to address that issue and a valuable supplement to cardiac magnetic resonance imaging. In the present article we review the literature in search of strengths and limitations of quantitative three-dimensional echocardiography for its clinical use in paediatric cardiology.

Right ventricular function assessment using tissue Doppler imaging and speckle tracking echocardiography.

Modern echocardiographic techniques, i.e. tissue Doppler imaging and speckle tracking echocardiography, allow for an assessment of global and regional right ventricular function. The right ventricular myocardial performance index and tricuspid annulus motion are used in the assessment of global right ventricular function, whereas duration of the cardiac cycle phases and myocardial velocities are used in the assessment of regional function. Strain and strain rate allow for an evaluation of both regional and global myocardial function. Literature reports provide data on the usefulness of these methods in patients with pressure and volume overload as well as with direct myocardial damage involving the right ventricle. In pulmonary hypertension, S' wave assessment may be used for therapeutic efficacy evaluation. Longitudinal strain reduction indicates an increased risk of vascular events, while an increased value of myocardial performance index is a predictor for a survival in pulmonary hypertension. A decreased S' wave velocity is associated with limited pulmonary vascular flow in patients with pulmonary embolism. In patients after atrial baffle repair for transposition of the great arteries, decreased longitudinal strain was an independent predictor for heart failure. A statistically significant decrease in both the S' wave as well as acceleration during isovolumic contraction were observed in arrhythmogenic right ventricular cardiomyopathy. S' wave and global right ventricular longitudinal strain values were lower in patients in the acute phase of myocardial infarction involving the right ventricle compared to the corresponding parameters in healthy individuals. In the case of tetralogy of Fallot correction, the evaluation of S' wave velocity may prove useful in identifying patients with reduced cardiac systolic reserve; a good correlation was also found between the global right ventricular longitudinal strain and right ventricular ejection fraction in MRI.

Assessment of left ventricular diastolic function in children after successful repair of aortic coarctation.

The purpose of the study was an assessment of left ventricular diastolic function in children after the successful repair of aortic coarctation (CoA). The prospective study concerned 32 pediatric patients after the CoA surgery. Tissue Doppler imaging parameters including strain and strain rate and the conventional echocardiographic indexes were analyzed in patients and healthy controls. Analysis of mitral annulus velocities, E-E' ratio, strain, and strain rate of left ventricular mid-cavity segments and conventional indexes of mitral inflow showed the worsening of left ventricular diastolic mechanics in the study group compared to healthy controls. The E/E' ratio was significantly higher in the study group compared to the control group (8.30 ± 3.24 vs. 6.95 ± 1.36; p < 0.05). The early diastolic strain rate to late diastolic strain rate ratio as well as early to late diastolic strain ratio of the left ventricular mid-cavity segments were significantly lower in the study group compared to healthy controls (1.81 ± 0.63 vs. 3.74 ± 1.53; p < 0.001 and 1.20 ± 0.49 vs. 3.41 ± 1.26; p < 0.001). No differences of the pulmonary venous flow parameters between those two groups were observed. The left ventricular diastolic mechanics in hypertensive patients after CoA repair did not differ from normotensive subjects. Hypertensive and normotensive children after surgical repair of CoA are found to have worsening of the left ventricular diastolic mechanics suggesting the impairment of the active myocardial relaxation.

Assessment of left ventricular systolic function using tissue Doppler imaging in children after successful repair of aortic coarctation.

UNLABELLED: SUMMARY AIM: Assessment of left ventricular systolic function in children after the successful repair of aortic coarctation using tissue Doppler imaging (TDI). METHODS: The study group consisted of 32 patients (mean age 12.0 +/- 4.2 years) after the aortic coarctation repair. The TDI parameters and the conventional echocardiographic endocardial and midwall indices of the left ventricular systolic function were analysed and compared with the results obtained from 34 healthy children. RESULTS: The systolic mitral annulus motion velocity, systolic myocardial velocity of the medial segment of the left ventricular septal wall, left ventricular strain and Strain Rate (SR) in the study group were significantly higher than in the control group, respectively: 6.92 +/- 0.75 cm s(-1) versus 6.45 +/- 0.83 cm s(-1); 5.82 +/- 1.03 cm s(-1) versus 5.08 +/- 1.11 cm s(-1); -28.67 +/- 6.04% versus -22.53 +/- 6.44% and -3.20 +/- 0.76 s(-1) versus -2.39 +/- 0.49 s(-1). Except midwall shortening fraction the conventional endocardial and midwall echocardiographic indices in the study group were significantly higher in comparison to the healthy controls. The left ventricular systolic meridional fibre stress and end-systolic circumferential wall stress did not differ between the examined groups. There were no differences of the TDI or conventional parameters between hypertensive and normotensive patients. CONCLUSIONS: Left ventricular systolic performance in children after the surgical repair of aortic coarctation reveals tendency to rise in late follow-up despite a satisfactory result after surgery. Higher systolic strain and SR in children treated due to coarctation of the aorta may suggest the increased preserved left ventricular performance despite normalization of afterload.

Assessment of right atrial and right ventricular size in children after percutaneous closure of secundum atrial septal defect with Amplatzer septal occluder.

INTRODUCTION: The aim of this study was to evaluate the right atrial (RA) and right ventricular (RV) size, and the speed of their normalization, in children after percutaneous closure of secundum atrial septal defect with the Amplatzer septal occluder. MATERIAL AND METHODS: The study group consisted of 42 children, aged 4.5 to 18.5 years. The following measurements (indexed to body surface area) were performed using 2D echocardiography: longitudinal, transverse axis and area of RA, RV inflow dimensions at one-third, and halfway between the tricuspid annulus and the apex (in the apical 4-chamber view), short axis and M-mode RV diastolic dimensions. All measurements were obtained 24 h and 1, 3 and 12 months after the procedure, then annually over 4 years of follow-up, and compared with the values obtained from the control groups. RESULTS: A significant decrease in all RA and RV values was observed after 24 h. Right ventricular transverse dimension normalized after 1 month, the RA longitudinal axis and area and the RV inflow dimensions after 3 months, and the RA transverse axis and M-mode RV diastolic dimension after 2 years, but the ratio of transverse to longitudinal RA axis remained significantly higher. CONCLUSIONS: Right atrial and right ventricular measurements decrease rapidly during the first 24 h, and most of them normalize within a 3-month period. M-mode RV diastolic dimension does not capture the real RV changes. Amplatzer septal occluder closure of ASD influences the RA geometry, which is reflected by the higher transverse to longitudinal RA axis ratio.

Usefulness of NT-proBNP in assessment of right ventricular function in children after tetralogy of Fallot correction - a preliminary study.

BACKGROUND: Although surgical treatment for tetralogy of Fallot (TOF) has been used with considerable success, right ventricular function may remain altered after repair. The NT-proBNP assessment has been shown to be a reliable parameter for the heart failure assessment. AIM: To determine NT-proBNP values in assessment of right ventricular function in children after TOF correction. METHODS: In 20 patients after TOF correction aged from 10 to 17 years (follow-up period ranged from 7 to 16 years) NT-proBNP level at rest and after exertion, treadmill test and echocardiography were performed. In the control healthy children NT-proBNP level at rest was assessed. RESULTS: The mean values of NT-proBNP level in the TOF patients were significantly higher than in controls (11.0 +/- 12.0 fmol/l and 5.4 +/- 7.5 fmol/l, p < 0.05). In patients repaired with a transannular patch the mean value of NT-proBNP level was higher than in children operated on without a transannular patch (18.3 +/- 16.5 vs. 6.8 +/- 7.9 fmol/l, p < 0.05). In children in whom physiological shortening of QRS complex during treadmill test was observed, NT-proBNP level was lower (mean values at rest 5.0 +/- 4.8 fmol/l and after exertion 7.3 +/- 6.3 fmol/l) compared to patients with prolongation of QRS duration (mean values at rest 17.7 +/- 15.6 fmol/l and after exertion 20.3 +/- 17.8 fmol/l) (p < 0.05). Significant differences in NT-proBNP levels between children with severe pulmonary regurgitation and mild/moderate pulmonary regurgitation were detected (mean values at rest 18.6 +/- 15.0 vs. 4.2 +/- 3.9 fmol/l and after exertion 20.0 +/- 18.6 vs. 5.7 +/- 4.6 fmol/l) (p < 0.05). The NT-proBNP levels were also higher in children with severe tricuspid valve insufficiency compared to children with mild/moderate tricuspid valve regurgitation (mean values at rest 19.5 +/- 15.0 vs. 4.9 +/- 3.7 fmol/l and after exertion 22.5 +/- 17.1 vs. 7.0 +/- 4.6 fmol/l). CONCLUSIONS: The NT-proBNP level in patients after TOF correction is higher than in healthy children. The NT-proBNP level is higher and exertion tolerance is lower in children repaired with rather than without transannular patch. In patients with severe pulmonary regurgitation and/or severe tricuspid valve insufficiency NT-proBNP level is higher than in patients without right ventricular volume overload. The measurement of NT-proBNP level might be helpful in order to separate those patients after TOF correction who are at increased risk of heart failure and arrhythmia.