Impact of multiplanar review of three-dimensional echocardiographic data on management of congenital heart disease.

BACKGROUND: In patients with congenital cardiac malformations, accurate diagnosis is critical in diagnosis and management. The multiplanar review mode (MPR) allows the operator to cut three-dimensional (3D) echocardiographic data sets in infinite planes, and to review the moving image in three simultaneous orthogonal planes. We sought to describe the clinical utility of MPR of 3D echocardiography for analysis of congenitally malformed hearts. METHODS: Cross-sectional and 3D MPR echocardiography was performed in 300 patients with congenitally malformed hearts. RESULTS: Analysis in multiplanar mode was possible in all patients. New, clinically important information, which altered management or changed the principal diagnosis, was obtained in 32 (11%) cases. This determined suitability for biventricular repair in 11 patients, clarified the morphology of atrioventricular valves in 7, helped in assessment of aortic, mitral, or prosthetic valvar disease in 13, and identified a vascular ring in the other patient. CONCLUSIONS: 3D MPR is feasible in the setting of the congenitally malformed heart, permitting focused and in-depth analysis. This substantially improves the understanding of functional morphology, above the information derived from cross-sectional echocardiography. We recommend the use of the 3D format with MPR for patients with complex congenital cardiac disease.

A multiplanar three dimensional echocardiographic study of mitral valvar annular function in children with normal and regurgitant valves.

INTRODUCTION: The mitral valvar complex is difficult to visualise accurately in only two dimensions. Three-dimensional echocardiography gives new insight into the dynamic changes of intra-cardiac structures during the cardiac cycle. The aim of this study was to study the mitral annulus in systole and diastole in normal children using three-dimensional echocardiography, and to analyse the effect of regurgitation on annular function. MATERIALS AND METHODS: Three-dimensional echocardiographic datasets, acquired in 11 consecutive subjects with mitral regurgitation, and 20 normal subjects, were analysed offline using simultaneous multiplanar review. RESULTS: The mitral valvar annular area decreased in diastole, and increased in systole, in both groups. The annulus in patients with mitral regurgitation is dilated compared to normal subjects, the systolic value for those with regurgitation having a mean of 6.79 plus or minus 2.55 centimetres2/metres2, and the diastolic value a mean of 5.01 plus or minus 1.78 centimetres2/metres2, as opposed to a systolic mean value of 5.28 centimetres2/metres2 plus or minus 1.68, p = 0.091, and diastolic mean value of 3.05 centimetres2/metres2 plus or minus 0.90, in normal subjects (p less than 0.0001). The proportional change in mitral valvar annular area from systole to diastole showed a trend towards being smaller in those with mitral regurgitation, although this did not reach significance (24.8% versus 41.13%, p equal to 0.249). Analysis of subgroups of patients with moderate or severe mitral regurgitation showed mitral excursion, expressed as percentage of left ventricular length, to be significantly less than in normal subjects, at 12.78 plus or minus 5.10% versus 15.84 plus or minus 4.23% (p equal to 0.012). CONCLUSIONS: Mitral valvar annular area in children decreases in diastole, and increases in systole. In those with mitral regurgitation, the annulus is dilated and the dynamic annular function is depressed.

Determinants of outcome in fetal pulmonary valve stenosis or atresia with intact ventricular septum.

Pulmonary valve stenosis or atresia with intact ventricular septum represents a spectrum of severity. This study aimed to identify ultrasound markers of biventricular versus non-biventricular outcome. The fetal echocardiograms of 41 fetuses diagnosed with pulmonary stenosis or atresia and right ventricular (RV)/left ventricular (LV) length ratios >0.4 from 17 to 31 weeks of gestation were reviewed. Of 27 live-born patients with intention to treat, 8 had non-biventricular outcomes and 19 had biventricular circulation. At the time of diagnosis, poor RV function, flow reversal in the arterial duct, the degree of tricuspid valve (TV) regurgitation, and inferior vena cava Doppler flow pattern did not differ between the 2 outcome groups. However, RV sinusoids, the RV/LV length ratio, the TV/mitral valve ratio, and TV inflow duration were significantly different. Cut-off values derived from receiver-operating characteristic curves yielding the best sensitivity and specificity for a non-biventricular outcome were TV/mitral valve ratio <0.7, RV/LV length ratio <0.6, TV inflow duration <31.5% of cardiac cycle length, and the presence of RV sinusoids. If 3 of these 4 criteria were fulfilled, this predicted a non-biventricular outcome with sensitivity of 100% and specificity of 75%. In conclusion, in fetuses < or =31 weeks of gestation with pulmonary stenosis or atresia and intact ventricular septum, progression to a non-biventricular outcome can be predicted by a 4-criterion scoring system. The criteria may be useful in selecting fetuses for prenatal catheter intervention to prevent progressive RV hypoplasia.

Assessment of the evolution of normal fetal diastolic function during mid and late gestation by spectral Doppler tissue echocardiography.

OBJECTIVE: To establish gestational age-specific reference values in healthy singleton fetuses, we prospectively assessed the evolution of diastolic longitudinal wall-motion velocities by spectral Doppler tissue imaging. METHODS: Early (Ea) and late diastolic (Aa) peak Doppler tissue imaging velocities were analyzed in 114 fetuses (age range: 14-42 weeks) at the base of right ventricular free wall, ventricular septum, and left ventricular free wall and compared with early (E) and late (A) diastolic peak Doppler inflow velocities. RESULTS: A linear increase in Ea, Aa, and Ea/Aa ratio was documented at all sites with advancing gestation. Likewise, the peak E flow velocities of both atrioventricular valves and the tricuspid peak A flow velocity increased. The ratio of peak E/Ea velocities decreased exponentially as a result of a more rapid increase in Ea than E, to reach a stable E/Ea relationship only in the early third trimester. CONCLUSIONS: There was a strong positive correlation between Ea and Aa velocities and gestational age indicating improved diastolic myocardial lengthening with advancing gestation. Reference charts for Doppler tissue imaging velocities were established that will allow identification of fetal diastolic function abnormalities.

Three-dimensional echocardiography improves the understanding of the mechanisms and site of left atrioventricular valve regurgitation in atrioventricular septal defect.

OBJECTIVES: The purpose of this study was to determine whether 3-dimensional echocardiography (3DE) provides additional information regarding the mechanisms and sites of left atrioventricular valve regurgitation in atrioventricular septal defect compared with transesophageal 2-dimensional echocardiography (2DE). METHODS: Eleven patients with a median age of 5.4 years (2.9-11.6 years) and a median weight of 16.8 kg (13.7-38.3 kg) with an atrioventricular septal defect underwent simultaneous transesophageal 2DE and 3DE before operation. RESULTS: The 2DE-3DE agreement for the assessment of the superior and mural leaflet size was 72.7%. The 2DE-3DE agreement for coaptation failure, a residual or primary cleft, and commissural abnormalities as a mechanism of regurgitation were 72.7%, 63.6%, and 36.4%, respectively. For jet sites the 2DE-3DE agreement was 63.6% for a commissural and central location. CONCLUSION: Three-dimensional echocardiography provides new and superior data regarding the mechanisms and sites of left atrioventricular valve regurgitation in atrioventricular septal defect.

The impact of patch augmentation on left atrioventricular valve dynamics in patients with atrioventricular septal defects: early and midterm follow-up.

OBJECTIVE: Left atrioventricular valve pericardial patch may prevent valve replacement. We assessed patch annular dynamics compared with conventional repair and normal annuli. METHODS: Transesophageal 3-dimensional echocardiography was acquired preoperatively and postoperatively in atrioventricular septal defects (n = 10, 5 patch, 5 conventional repair). Real-time 3-dimensional annular motion at midterm was compared with that of healthy children (n = 10). Parameters were: annular area, perimeter, segmental diameter, bending angle, stenosis, and regurgitation. RESULTS: Regurgitant jet area ratio decreased in both patient groups. Conventional repair reduced annular area (P = .02). Patch repair showed an annular area larger than normal (P = .01). Control subjects had increased systolic area whereas operative groups showed a reduction. Patch repair had segmental diameters similar to normal whereas conventional repair was inhomogeneous. Annular bending angle was maintained after operation. CONCLUSION: Patch repair in pediatrics shows durability without shrinkage or expansion. Improved stenosis and regurgitation does not change by midterm. Operation causes increased annular stiffness and diminished compliance. Neither technique establishes normal annular eccentricity.

Three-dimensional tricuspid annular function provides insight into the mechanisms of tricuspid valve regurgitation in classic hypoplastic left heart syndrome.

BACKGROUND: Tricuspid regurgitation (TR) has a negative impact on outcome in hypoplastic left heart syndrome (HLHS). There is a paucity of data assessing the mechanisms of TR. Lateral forces from the left ventricle play an important role in normal tricuspid valve (TV) function. This study evaluates the role of real-time 3-dimensional echocardiography in the assessment of the TV annulus and subvalvular apparatus in HLHS. METHODS: In all, 31 real-time 3-dimensional echocardiographic studies from 26 patients (1 day-17 years old) with classic HLHS were included. In all, 7 studies were before and 8 were after first-stage palliation; 8 were postcavopulmonary shunt and 8 were post-Fontan. Only patients with severe left ventricular attenuation were included. Studies were subdivided into two groups: mild TR (N = 20) and severe TR (STR) (N = 11). Data from 17 control subjects were used for comparison. TV annular area, bending angle (saddle shape), and position of anterior papillary muscle were analyzed. RESULTS: All annular segments moved in equally during systole in mild TR, whereas septal-lateral diameter contraction was significantly diminished in STR. TV annular area was larger in HLHS (mild TR, 1265 +/- 325; STR, 1767 +/- 450 mm2/m2) than in control subjects (762 +/- 85) (P < .001). However, area change was reduced only in STR (12.4 +/- 4.6% vs control subjects 20.4 +/- 8.3%, P < .05). Annular shape was flat during systole in HLHS. Anterior papillary muscle was laterally displaced in STR. CONCLUSIONS: TV annular dynamics were different in patients with HLHS as a result of lack of interaction form left ventricle. Annular function, especially in septal-lateral direction, was further impaired in STR.

Doppler tissue imaging in the assessment of atrioventricular conduction time: validation of a novel technique and comparison with electrophysiologic and pulsed wave Doppler-derived equivalents in an animal model.

Accurate assessment of atrioventricular conduction time (AVCT) is crucial for early detection of evolving fetal heart block. Simultaneous pulsed wave Doppler (PD) interrogation of left ventricular inflow and outflow is mainly used to study fetal AVCT. Limitations of this modality include its dependency on loading conditions and merging early and late diastolic inflow waves at faster heart rate (HR). Sequential analysis of atrioventricular myocardial motion by Doppler tissue imaging (DTI) might be more useful in this regard. In 15 open-chest pigs, AVCT was measured by PD, DTI, and electrocardiogram at baseline HR and during incremental atrial pacing up to 200 beats/min. Electromechanical delay and pre-ejection period were assessed at baseline and maximal HR. DTI-derived AVCT correlated better with PR intervals and allowed measurements at faster HRs than did PD (P < .05). Pre-ejection period prolonged with faster HR (P < .001), unlike electromechanical delay. In conclusion, DTI allows more accurate measurement of AVCT over a wider HR range than does PD.

Hemodynamic evaluation of the peripheral pulmonary circulation by cine phase-contrast magnetic resonance imaging.

PURPOSE: To describe the normal flow patterns in peripheral pulmonary vessels with phase-contrast (PC) magnetic resonance imaging (MRI). MATERIALS AND METHODS: Twelve healthy adults (age = 33 +/- 7 years) underwent cine PC MRI of the segmental and central pulmonary arteries and veins by means of a breath-held segmented k-space technique. Flow patterns were analyzed on time-velocity curves and compared between the peripheral and central vessels. RESULTS: The pulsatile flow patterns in the segmental arteries and veins were similar among individuals. When compared with the central pulmonary arteries, the segmental arteries had a delay in the systolic and diastolic flow velocity waves, and an increased magnitude of the diastolic peaks, in relation to the systolic peaks. A prominent notch was present during the deceleration phase of the systolic flow velocity wave in 79% of the segmental arteries investigated. The segmental veins showed a typical pulmonary venous flow pattern, as seen in the central veins, with similar systolic-to-diastolic peak velocity ratios. CONCLUSION: Noninvasive evaluation of blood flow in intraparenchymal pulmonary vessels is feasible with PC MRI. This first description of normal flow patterns in segmental pulmonary arteries and veins can serve as basis for further investigation in the setting of altered pulmonary blood flows.

Insight into normal mitral and tricuspid annular dynamics in pediatrics: a real-time three-dimensional echocardiographic study.

BACKGROUND: Although there are animal or adult studies analyzing annular motion of the mitral valve (MV) or tricuspid valve (TV) separately, there are no data analyzing interaction between the MV and TV, or data from the pediatric population. METHODS: A total of 17 healthy children (age 3-15 years) were enrolled in this study. Using real-time 3-dimensional echocardiography, annular area, perimeter, segmental diameter, and bending angle were obtained and analyzed. RESULTS: MV area increased during systole, in contrast to TV area, which decreased. TV area demonstrated a greater reduction of lateral diameter during systole. Bending motion became most acute in early diastole, which was greater for the TV. CONCLUSIONS: MV area change differs from adults, which may be explained by a more compliant myocardium in children. Greater lateral forces on TV prevent it from becoming circular, thus, preserving valve competency. Both valves show a bending motion, which becomes most prominent during isovolumic relaxation continuing into early diastole for the TV, suggesting a relationship with torsional forces within the ventricles.

How is pulmonary arterial blood flow affected by pulmonary venous obstruction in children? A phase-contrast magnetic resonance study.

BACKGROUND: Hemodynamic changes within a stenosed pulmonary vein might not reflect the severity of the obstruction if redistribution of pulmonary artery flow occurs. OBJECTIVE: The purpose was to investigate flow changes in branch pulmonary arteries in the presence of pulmonary vein stenosis. MATERIALS AND METHODS: Twelve children (age range 3-180 months) who had undergone MRI for pulmonary vein stenosis were identified. The severity of vein stenosis was assessed from percentage diameter reduction. Pulmonary artery flow distribution was correlated with the severity of pulmonary vein stenosis. Nine of the patients had unilateral stenosis; three had bilateral involvement. RESULTS: Unilateral vein stenosis was associated with diastolic reversal in the ipsilateral branch pulmonary artery (mean flow reversal 12.3%, range 2.4-42%) and continuous diastolic forward flow in the contralateral pulmonary artery in seven of nine patients. Severe stenosis was associated with decreased systolic flow to the ipsilateral lung. The ratio of net forward flow through pulmonary arteries correlated well with the cross-sectional area ratio of pulmonary arteries (r=0.75, P=0.006). CONCLUSIONS: Severe pulmonary vein obstruction results in redistribution of pulmonary arterial flow. When investigating pulmonary vein stenosis by MR, an evaluation of the pulmonary arterial system should be included to assess the functional importance of an obstruction.

Comparative imaging of differential pulmonary blood flow in patients with congenital heart disease: magnetic resonance imaging versus lung perfusion scintigraphy.

BACKGROUND: Lung perfusion scintigraphy is considered the gold standard to assess differential pulmonary blood flow while magnetic resonance (MR) has been shown to be an accurate alternative in some studies. OBJECTIVE: The purpose of the study was to assess the accuracy of phase contrast magnetic resonance (PC-MR) in measuring pulmonary blood flow ratio compared with lung perfusion scintigraphy in patients with complex pulmonary artery anatomy or pulmonary hypertension and to document reasons for discrepant results. MATERIALS AND METHODS: We identified 25 cases of congenital heart disease between January 2000 and 2003, in whom both techniques of assessing pulmonary blood flow were performed within a 6-month period without an interim surgical or transcatheter intervention. The study group included cases with branch pulmonary artery stenosis, intracardiac shunts, single ventricle circulation, pulmonary venous anomalies and conotruncal defects. The mean age at study was 5.7 years (range 0.33-12) with a mean weight of 20.3 kg (range 6.5-53.6). The two methods were compared using a Bland-Altman analysis, and the Pearson correlation coefficient was calculated using the lung scan as the gold standard. Discrepant results were examined by reviewing the source images to elucidate reasons for error by MR. RESULTS: Bland-Altman analysis comparing right pulmonary artery (RPA) blood flow percentage, as measured by each modality, showed a mean difference of 1.43+/-9.8 (95% limits of agreement: -17.8, 20.6) with a correlation coefficient of r=0.84, P<0.0001. In six (24%) cases a large difference (>10%) was found with a mean difference between techniques of 17.9%. The reasons for discrepant results included MR artifacts, dephasing owing to turbulent flow, site of data acquisition and lobar lung collapse. CONCLUSION: When using PC-MR to assess pulmonary blood flow ratio, important technical errors occur in a significant proportion of patients who have abnormal pulmonary artery anatomy or pulmonary hypertension. If these technical errors are avoided, PC-MR is able to supply both anatomic and quantitative functional information in this patient population.

Different techniques for closure of multiple interatrial communications with the Amplatzer septal occluder.

We present three cases of multiple interatrial communications to illustrate the extended use of the Amplatzer septal occluder and to highlight procedural techniques. The first case demonstrates how a single device can be used to close two adjacent defects. It is important to balloon size both defects and to note if balloon occlusion of one defect closes the other and vice versa. The second case demonstrates closure of multiple atrial septal defects using two devices. The technique needed to obtain an "interleaved" position of the two devices is detailed. This technique allows for a lower profile that reduces stress on the devices and surrounding structures and may decrease the risk of thromboembolism and device embolization. The third case describes device closure of a residual defect adjacent to a previous device implanted at an earlier sitting. In this situation, an overlapping position without the option for "interleaving" is inevitable.

Obstructed hemianomalous pulmonary venous drainage: is intervention necessary?

Obstructed infradiaphragmatic hemianomalous pulmonary venous drainage is associated with high mortality and morbidity, and treatment is best tailored to the individual patient. Resolution of an obstructed scimitar vein through collateralization has rarely been reported. We report two such cases and review the literature.