Howard D. Apfel

Comparison of three-dimensional echocardiographic assessment of volume, mass, and function in children with functionally single left ventricles with two-dimensional echocardiography and magnetic resonance imaging

Diminished systolic function or inappropriate hypertrophy are considered risk factors for outcome following the Fontan procedure. These parameters are difficult to assess in univentricular hearts that do not conform to the uniform shapes prescribed by conventional 2-dimensional imaging volume algorithms. Three-dimensional echocardiography requires no geometric assumptions and has been validated in both normal and distorted left ventricles. To assess the feasibility and accuracy of this technique in patients with univentricular hearts, we compared 2- and 3-dimensional echocardiographic estimates of ventricular volume, ejection fraction, and mass in patients with functionally single left ventricles with results obtained by magnetic resonance imaging (MRI). Twelve patients with functionally single left ventricles (6 months to 22 years) underwent examination by all 3 modalities. Correlation and agreement with MRI were calculated for volumes, ejection fraction, and mass. Three-dimensional echocardiographic comparison with MRI yielded a bias of 3.4 +/- 5.5 ml and 14.2 +/- 8.3 ml for systolic and diastolic volumes, respectively. Agreement analysis for mass showed a bias of 5.8 +/- 8.4 grams. Two-dimensional echocardiography showed less agreement for both volumes and mass (bias of -2.9 +/- 8.1, 2.9 +/- 10.4 ml and -8.3 +/- 12.0 g for volume and mass, respectively, p >0.05). Ejection fraction by 3-dimensional echocardiography showed significantly closer agreement with MRI (bias of 4.4 +/- 5.3%) than 2-dimensional echocardiography (bias of 8.5 +/- 10.3%, p = 0.04). Thus, 3-dimensional echocardiography provides estimates of ventricular volumes, ejection fraction, and mass that are comparable to MRI in this select group of patients with single ventricles of left ventricular morphology.

Serial echocardiographic measurements of the pulmonary autograft in the aortic valve position after the Ross operation in a pediatric population using normal pulmonary artery dimensions as the reference standard.

Serial echocardiographic measurements of the annulus and sinus were obtained in children before the Ross operation, and early and late postoperatively. Values were compared with normal standards for the aorta and pulmonary artery (PA). There was no significant difference between PA annulus measurements before surgery and the corresponding autograft immediately afterward (1.73 +/- 0.60 cm preoperatively; 1. 63 +/- 0.58 cm postoperatively, p = NS). Late after surgery the mean annulus diameter was enlarged compared with the normal aorta (DeltaZ 1.9 +/- 2.4), but remained relatively unchanged compared with the normal PA (DeltaZ 0.7 +/- 1.1, p <0.01). In contrast, the autograft sinus was dilated early after surgery (1.83 +/- 0.58 cm preoperatively; 2.18 +/- 0.73 cm postoperatively, p <0.01). Mean sinus Z score further increased compared with both the aorta (DeltaZ 1.3 +/- 1.7) and PA (DeltaZ 1.3 +/- 1.6). Use of standard PA measurements may be important in the assessment of autograft enlargement. Minimal change in autograft Z scores over time suggests that annulus enlargement is mainly due to somatic growth. In contrast, the autograft sinus showed an immediate and continued disproportionate increase in size over time, suggesting that sinus enlargement is largely due to passive dilation.

Feasibility of a two-dimensional echocardiographic method for the clinical assessment of right ventricular volume and function in children.

The relative ease of acquisition and safety of two-dimensional echocardiography has established it as the mainstay for routine cardiac imaging. Translation of imaging data into useful quantitative information, however, requires fitting the ventricle to a specific geometric model. Because of its complex shape and anterior position, many attempts at right ventricular quantitation by two-dimensional echocardiography have been criticized as impractical and not reproducible. A simple method incorporating subcostal and apical imaging was introduced in 1984. This approach appeared to combine accuracy and practicability but was never validated in a clinical setting because of the difficulties of subcostal imaging in adults. This study assessed the feasibility and accuracy of this technique in the pediatric population. Results of volume comparison to values derived by magnetic resonance imaging were r = 0.96, standard error of the estimate (SEE) = 19.3 ml, and mean difference = 15 +/- 19.4 ml and r = 0.97, SEE = 12.3 ml, and bias = 5 +/- 11.8 ml for diastolic and systolic volumes, respectively. Comparison of estimates of ejection fraction with magnetic resonance imaging demonstrated r = 0.90, SEE = 5.9%, and bias = 3% +/- 5.7%. Interobserver and intraobserver variability was 9.9% and 8.2%, respectively, for systolic volumes and 11.5% and 8.9%, respectively, for diastolic volumes. Evaluation of right ventricular size and function by this approach is comparable to determinations by magnetic resonance imaging and may be clinically useful in the management of pediatric patients.

Late Left Ventricular Function After Surgery for Children With Chronic Symptomatic Mitral Regurgitation

BACKGROUNDnThe use of quantitative echocardiography has been emphasized in optimizing timing of surgery in adult patients with mitral regurgitation to avoid irreversible left ventricular dysfunction. In contrast, surgery for infants and children is often delayed until the appearance of severe symptoms because of the patients size and anticoagulation requirements and the possible need for early reoperation. The purpose of this study was to determine long-term ventricular function after mitral valve surgery in symptomatic children and to analyze risk factors for adverse outcome.nnnMETHODS AND RESULTSnThirty-three patients (0.5 to 19 years old) operated on for mitral regurgitation as a single hemodynamically significant lesion were studied. All but 3 had medically refractory symptoms. One patient died during surgery, and 32 were followed for 0.3 to 17.1 years (mean, 4.5 years). The mean preoperative left ventricular shortening fraction was 0.38+/-0.09. Successful mitral valvuloplasty or replacement was documented by long-term normalization of end-diastolic dimensions. Early postoperative shortening fraction was significantly reduced (0.28+/-0.1, P<.01), but it improved to 0.40+/-0.07 (P<.01) on late follow-up, at which time only 1 patient had ventricular dysfunction. Preoperative shortening fractions did not correlate well with early or late postoperative values (r=.18 and r=.31, respectively). Seven of 32 surviving patients had preoperative shortening fractions <0.33 (mean, 0.26+/-0.05) and 25 >0.33 (mean, 0.39+/-0.08). Analysis of these subgroups showed no significant differences between the groups in early or late postoperative function. Duration of mitral insufficiency appeared to be associated with the development of atrial arrhythmias.nnnCONCLUSIONSnLate left ventricular function normalizes in children after surgical correction of mitral insufficiency. In contrast to adults, delay of surgery in children with significant mitral regurgitation until the onset of severe symptoms does not increase the risk for long-term ventricular dysfunction, although late atrial arrhythmias are more likely to be encountered.

Psychiatric disorders in youth with medically unexplained chest pain versus innocent heart murmur.

OBJECTIVEnTo examine the prevalence of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition psychiatric disorders in youth with chest pain compared with a control sample with innocent heart murmur.nnnSTUDY DESIGNnWe assessed youth ages 8 to 17 years who were examined in cardiology settings for medically unexplained chest pain (n=100) or innocent heart murmur (n=80). We conducted semi-structured interviews and assessed medical history, quality of life, and disability.nnnRESULTSnYouth with chest pain had a higher prevalence of psychiatric disorders compared with youth with murmur (74% versus 47%, χ(2)=13.3; P<.001). Anxiety disorders predominated, although major depression was also more common in the chest pain group (9% versus 0%; Fisher exact tests; P<.01). Onset of psychiatric disorders generally preceded chest pain. Patterns were similar for boys and girls and for children and adolescents. Chest pain was associated with poorer quality of life and with pain-related disability for youth with co-morbid psychiatric disorder.nnnCONCLUSIONSnIn childhood and adolescence, medically unexplained chest pain is associated with a high prevalence of psychiatric disorders. Systematic mental health screening may improve detection and enhance treatment of these patients.

Clinical evaluation, medical management and outcome of atrioventricular canal defects

Abstract The relative effects of interatrial shunting, interventricular shunting and atrioventricular valve function will determine the general course of patients with atrioventricular canal defects. This report reviews the natural history, medical management and current outcome of this group of patients. The overall long-term survival of patients with primum atrial septal defect following repair was found to match that of the general population. Results following complete AV canal repair have similarly improved significantly in the last decade. However, residual mitral valve dysfunction remains an important post-operative issue. Straddling, stenosis or atresia of part of the AV valve, often results in significant hypoplasia of a ventricular chamber. In extreme cases, the management will generally follow that of other single ventricle variants, eventually resulting in Fontan palliation. The clinical course and outcome of these and other complex variants such as atrioventricular canal defect with tetralogy of Fallot is discussed.

1003-5 Feasibility of a Two Dimensional Echocardiographic Method for the Clinical Assessment of Right Ventricular Volume and Function

Obtaining non-invasive measurements of right ventricular (RV) volume and function has been a long standing challenge. Radionuclide techniques (MUGA) for RV evaluation are limited by problems of border recognition and chamber overlap. Magnetic Resonance Imaging (MRI) measurements of ventricular volumes have been previously validated; however, this technique is limited by expense and time necessary for acquisition and analysis. A 2D echo technique has been previously described (Levine et al Circ 69: 497) that uses the simple product of length and area measurements of two orthogonal planes (apical 4 chamber and subxyphoid short). Apical (AP) and RV Outflow (OT) methods were used. Good correlation has been reported in vitro, however, no validation in a clinical setting has been reported to date. We obtained 20 echo measurements of RV volumes and election fraction (EF) by this method and compared our results to MRI data in patients over a wide range of volumes and function, 8 patients were studied, ages ranged from 5 to 42 years. Results Regression Bias (mean percent differences) Variability (intra- observer) 20 vs. MRI MRI range r SEE EDV (AP) 7 53–302xa0ml 0.99 13xa0l3 –24% 12% ESV (AP) 7 27–224xa0ml 0.99 9xa0ml –19% 13% EF (AP) 7 27–63% 0.99 4% –27% EDV (OT) 8 0.98 13xa0ml –24% 5% ESV (OT) 8 0.99 7xa0ml –30% 15% EF (OT) 8 0.96 4% –5% Conclusions Preliminary data show an excellent correlation and small SEE of 2d echo volumes and EF compared to MRI. There is a significant 2D echo bias underestimating MRI. Assessment of EF by this 2D method may be clinically useful for serial follow up of RV function.