Assessment of right ventricular size and function: echo versus magnetic resonance imaging

OBJECTIVE

The assessment of right ventricular (RV) size and function is important in the management of many patients with heart disease. Although magnetic resonance imaging (MRI) is considered the gold standard for quantitation of ventricular volumes and systolic function, subjective assessment ("eyeball") by echocardiography is the modality most often used for the RV. The echocardiographic "eyeball" method of assessing RV size and systolic function was compared with quantitative MRI.

DESIGN

Patients with right-sided congenital heart disease who underwent an echocardiogram within 6 months of MRI formed the study group. Four echocardiographers blinded to the MRI results reviewed the echocardiograms to subjectively assess RV size and systolic function. The reliability of an echocardiographer in accurately identifying a severely dilated RV and moderately to severely diminished RV systolic function was measured using the Kappa coefficient. Inter-rater agreement was also assessed using Kappa.

RESULTS

The study group consisted of 22 patients aged 16.6 +/- 7.1 years, with interval between MRI and echocardiogram of 49 +/- 54 days. Using echocardiography, reliability for accurately identifying a severely dilated RV was "slight" with a prevalence-adjusted bias-adjusted Kappa (PABAK) of 0.25; and for identifying moderately to severely diminished RV systolic function was fair with a PABAK of 0.43. Inter-rater agreement analysis was poor for both with Kappas of 0.07 (P = .22) and 0.12 (P = .09), respectively.

CONCLUSION

The usefulness of the echocardiographic "eyeball" method to estimate RV size and systolic function in patients with right heart disease has limitations when compared with MRI, specifically in regard to the variability between echocardiographers.

Physical activity levels in children and adolescents are reduced after the Fontan procedure, independent of exercise capacity, and are associated with lower perceived general health

OBJECTIVES

To determine physical activity levels in paediatric patients who underwent the Fontan procedure, and their relationship to functional status and exercise capacity.

STUDY DESIGN

We studied 147 patients (ages 7-18 years) at a median of 8.1 years after Fontan, as part of the Pediatric Heart Network cross-sectional study of Fontan survivors. Assessment included medical history, self-reported physical activity, parent-completed Child Health Questionnaire (CHQ), cardiopulmonary exercise testing and physical activity level measured by accelerometry (MTI Actigraph).

RESULTS

Measured time spent in moderate and vigorous activity was markedly below normal at all ages, particularly in females, and was not significantly related to self-reported activity levels, or to maximum Vo2, Vo2 at anaerobic threshold or maximum work rate on exercise testing. Lower measured activity levels were significantly related to lower perceived general health but not to self-esteem, physical functioning, social impact of physical limitations or overall physical or psychosocial health summary scores. Reduced exercise capacity was more strongly related than measured activity levels to lower scores in general health, self-esteem and physical functioning.

CONCLUSIONS

Physical activity levels are reduced after Fontan, independent of exercise capacity, and are associated with lower perceived general health but not other aspects of functional status.

Intermediate-term results of repair for aortic, neoaortic, and truncal valve insufficiency in children

OBJECTIVE

Repair of aortic valve insufficiency is difficult, and durability is relatively unknown in children. This study evaluates the intermediate-term results of repair of the systemic semilunar valve, including the native aortic valve, neoaortic valve (anatomic pulmonary), and truncal valve.

METHODS

We reviewed the records of 54 children (aged 2 days to 18 years) who underwent repair of the functional aortic valve for moderate or greater insufficiency from 1991 to 2005. Valve anatomy was tricuspid aortic in 26 patients, bicuspid aortic in 11 patients, tricuspid neoaortic in 9 patients, bicuspid neoaortic in 1 patient, and truncal valve in 7 patients. Multiple surgical techniques were used in most of the 54 patients, including leaflet plication in 17, leaflet repair in 15, commissuroplasty in 32, pericardial cusp augmentation in 8, and sinus of Valsalva reduction in 3.

RESULTS

There was 1 early death and no late deaths. Actuarial freedom from reoperation was 68% at 5 years and 58% at 10 years. Freedom from aortic valve replacement was 82% at 5 years and 73% at 10 years. Duration of cardiopulmonary bypass was the most significant risk factor for reoperation with multivariate analysis. Of the 40 patients who have not undergone reoperation, 37 have had follow-up echocardiograms with the latest study (4.5 +/- 4.2 years) demonstrating trace to 1+ insufficiency in 23 patients, 1 to 2+ in 12 patients, 2 to 3+ in 1 patient, and 3 to 4+ in 1 patient.

CONCLUSION

Repair of the insufficient systemic semilunar valve offers acceptable 10-year freedom from reoperation and functional results, and should be considered for most children.

Design of a large cross-sectional study to facilitate future clinical trials in children with the Fontan palliation

BACKGROUND

Clinical trials in children with congenital heart disease are often limited by the absence of the following: (1) a primary outcome that can be observed in a reasonable period; (2) information regarding health-related quality of life; (3) knowledge of the correlation between health status and ventricular function and exercise performance; (4) a sufficient number of children at a single institution to provide adequate statistical power; and (5) procedural and management differences between and within institutions.

METHODS

The NHLBI-funded Pediatric Heart Network designed a cross-sectional study of children aged 6 to 18 years, from 7 pediatric clinical centers, who had undergone a Fontan procedure as treatment for congenital heart disease. Health-related quality of life was measured by the Child Health Questionnaire and the Congenital Heart Adolescent and Teenager Questionnaire. Ventricular function was assessed by maximal exercise testing, echocardiography, cardiac magnetic resonance imaging, and B-type natriuretic peptide. The study was designed to detect a correlation of R > or = 0.30 between health status scores and measures of ventricular function and performance in a subcohort with all study measures completed.

RESULTS

A total of 1078 children were screened by chart review; 644 (60%) were eligible. The consent rate was 85% and 546 children were enrolled. Acquisition of echocardiograms, B-type natriuretic peptide, and health status was > or = 94%; completion rates were lower for maximal exercise testing (76%) and cardiac magnetic resonance imaging (41%).

CONCLUSIONS

This large study provides unique information regarding the relationship between health status and clinical measures in post-Fontan patients that will facilitate the design of future randomized trials.

Relationship of Patient and Medical Characteristics to Health Status in Children and Adolescents After the Fontan Procedure

BACKGROUND

After the Fontan procedure, patients are at risk for suboptimal health status related to their complex healthcare experience, physiological limitations, medical complications, and guarded long-term prognosis.

METHODS AND RESULTS

In the Pediatric Heart Network cross-sectional study of Fontan survivors 6 to 18 years of age, parents completed the Child Health Questionnaire, and scores were related in multivariable analysis to patient and medical characteristics obtained from medical record review. For 537 patients (mean age at study, 11.9 years; 60% male) with a median age at Fontan of 2.8 years (range, 0.7 to 14.6 years), parent-reported patient morbidities included deficits in vision in 33%, speech in 27%, and hearing in 7%, as well as problems with attention in 46%, learning in 43%, development in 24%, behavior in 23%, anxiety in 17%, and depression in 8%. Child Health Questionnaire summary scores were significantly lower than the US population sample for Physical Functioning (mean Z score, -0.47+/-1.19; P<0.001) and Psychosocial Functioning (-0.28+/-1.08; P<0.001). Parent-reported medical conditions and long-term and current medical problems explained the greatest amount of variation in the Physical Functioning scores. Parent-reported patient conditions, including behavior, learning, anxiety, and attention problems and depression, explained the greatest amount of variation in the Psychosocial Functioning scores. Lower family income had a negative impact on both Physical and Psychosocial Functioning.

CONCLUSIONS

There are deficits in health status in children and adolescents after the Fontan procedure. Strategies to address this problem might emphasize coordinated and effective prevention, detection, and management of noncardiac and psychosocial conditions, as well as specific targeting of patients from low-income households.

Ventricular remodeling in children with left ventricular dysfunction secondary to various cardiomyopathies

The ventricular remodeling that occurs in adults with left ventricular (LV) dysfunction is characterized by a change in LV shape from an ellipse to more of a sphere and is associated with increased functional mitral regurgitation (MR), decreased exercise tolerance, and poor outcome. There are limited data on the occurrence and importance of LV remodeling in children with LV dysfunction. The purposes of this study were to evaluate in children with LV dysfunction (1) LV shape, (2) changes in LV shape as LV function improves, and (3) the relation between LV shape and functional MR. Children with LV dysfunction were identified and compared with controls. Patient demographics, treatment, and outcomes were noted. Echocardiograms were reviewed for LV function and shape (sphericity index). The echos of a subset of children whose LV ejection fractions (LVEFs) increased by >10% over a follow-up of >6 months were analyzed for changes in sphericity, mitral annulus size, and the degree of MR. Twenty-five children with LV dysfunction were compared with 37 age-matched controls. LV remodeling to a more spherical shape was inversely related to LVEF but was not associated with clinical outcome. In a subset of patients (n = 17) whose LVEFs improved, the reversal of remodeling (decrease in sphericity index) was associated with a decrease in MR and mitral annulus size. In conclusion, LV remodeling occurs in children with LV dysfunction. The reversal of this remodeling with a decrease in the degree of MR and the size of the mitral annulus occurs as systolic function improves.

Follow-up of aortic coarctation repair in neonates

OBJECTIVES

The purposes of this study were to assess the growth of left heart (LH) structures, to evaluate midterm outcomes, and to define echocardiographic parameters predictive of increased risk of re-intervention in patients born with aortic coarctation and hypoplasia of LH structures that underwent neonatal coarctation repair.

BACKGROUND

Neonatal coarctation is often associated with hypoplasia of LH structures. Although previous studies have shown that coarctation repair can be performed with good results in these neonates, there are little data regarding growth of the LH structures or outcomes in these patients.

METHODS

Patients with isolated coarctation and at least one hypoplastic LH valve (mitral or aortic Z-score <-2) who underwent a neonatal coarctation repair were identified. Clinic charts and the latest echocardiograms were reviewed.

RESULTS

All 55 patients were alive and well, and no patient had clinical evidence of mitral stenosis. Three patients (5%) required re-intervention. Thirty-eight patients had echocardiograms that demonstrated normal left ventricular (LV) size and function with a follow-up duration of 73 +/- 19 months (range 3 to 9 years). Both mitral and aortic annulus Z-scores increased significantly: -3.1 +/- 1.5 to -0.5 +/- 1.6 (p < 0.001) and -3.5 +/- 1.9 to 0.7 +/- 1.6 (p < 0.001), respectively. Nine patients (24%) developed LV outflow tract obstruction by echocardiographic criteria.

CONCLUSIONS

After neonatal coarctation repair with associated LH hypoplasia, LH structures increase substantially in size, and clinical outcomes are excellent at midterm follow-up. Despite initial annular hypoplasia, the need for intervention for mitral or aortic/subaortic stenosis is uncommon.

Phenylglycine derivatives as antagonists of group III metabotropic glutamate receptors expressed on neonatal rat primary afferent terminals

1. Three novel phenylglycine analogues; (RS)-alpha-methyl-3-chloro-4-phosphonophenylglycine (UBP1110), (RS)-alpha-methyl-3-methoxy-4-phosphonophenylglycine (UBP1111) and (RS)-alpha-methyl-3-methyl-4-phosphonophenylglycine (UBP1112) antagonised the depression of the fast component of the dorsal root-evoked ventral root potential induced by (S)-AP4 with apparent K(D) values of: 7.4+/-2.3, 5.4+/-0.6 and 5.1+/-0.3 micro M (all n=3), respectively. 2. A Schild analysis of the antagonism of (S)-AP4 induced depression of synaptic transmission by UBP1112 revealed a pA(2) value of 5.3 and a slope of 0.81+/-0.26 (n=9). 3. None of the phenylglycines tested were potent antagonists of responses mediated by group II mGlu receptors (apparent K(D) values >480 micro M). UBP1112 when tested at a concentration of 1 mM had little or no activity on (S)-3,5-DHPG-, NMDA-, AMPA- or kainate-induced responses on motoneurones. 4. UBP1110, UBP1111 and UBP1112 are at least 100-fold selective for group III over group I and II mGlu receptors expressed in the spinal cord making them the most potent, selective, antagonists yet tested at (S)-AP4 sensitive receptors in the spinal cord.

Immunogenicity of decellularized cryopreserved allografts in pediatric cardiac surgery: comparison with standard cryopreserved allografts

BACKGROUND

Recognition of the immunogenicity of standard cryopreserved allografts has led to the development of new decellularized allografts (CryoValve SG; CryoLife, Inc, Kennesaw, Ga). This preliminary study examined the HLA antibody response to these decellularized allografts and compared it with the response to standard allograft material.

METHODS

We prospectively measured the frequency of panel-reactive HLA class I (HLA-A, HLA-B, and HLA-C) and class II (HLA-DR/DQ) alloantibodies in 14 children (age 8.5 +/- 7.9 years) receiving decellularized, cryopreserved allografts, including 6 undergoing allograft patch insertion and 8 with a valved pulmonary allograft. We compared them with 20 historical control subjects (age 1.7 +/- 2.4 years) undergoing implantation of standard cryopreserved allografts, 8 with valves and 12 with allograft patch. All patients had panel-reactive antibody levels measured before and at 1, 3, and 12 months after the operation. HLA class I and class II panel-reactive antibody levels were determined with a sensitive flow cytometry technique.

RESULTS

We found panel-reactive antibody levels in decellularized allografts to be elevated slightly from preoperative levels for both class I and class II antibodies at 1, 3, and 12 months (P >.05). The panel-reactive antibody level for both class I and class II antibodies were significantly lower for decellularized allografts as compared to standard allografts. Functionally, the allografts were similar with decellularized valved grafts showing a peak echo-determined systolic gradient of 13 +/- 15 mm Hg at 8 +/- 2.6 months postoperatively as compared to a gradient of 24 +/- 18 mm Hg measured 12 +/- 6 months postoperatively in standard allografts (P =.11).

CONCLUSIONS

Decellularized grafts elicited significantly lower levels of class I and class II HLA antibody formation at 1, 3, and 12 months after implantation than did standard cryopreserved allografts. Early hemodynamic function of decellularized grafts was similar to that of standard cryopreserved allograft valves. Further experience is necessary to determine whether the reduced immunogenicity of decellularized allografts will truly allow tissue ingrowth and improved long-term durability in patients.

Evidence for lack of myocardial injury in children with acute rheumatic carditis

Despite pathologic evidence of myocardial inflammation, the significance of myocarditis in children with acute rheumatic carditis remains controversial. Elevations in cardiac troponin I have been demonstrated in other forms of myocarditis. The purpose of our study was to determine if levels of cardiac troponin I are elevated, suggesting myocardial injury, in patients with acute rheumatic carditis. We identified all those patients with acute rheumatic fever, presenting between July 1998 and December 2000, who had clinical evidence of carditis, such as a new murmur of mitral or aortic regurgitation, and who had an echocardiogram, measurements of levels of cardiac troponin I, erythrocyte sedimentation rate, and/or C-reactive protein performed at the time of presentation. Their charts were reviewed for demographic and clinical data. Echocardiograms were reviewed for severity of aortic and mitral regurgitation, and measurements made of left ventricular ejection fraction, fractional shortening, and end-diastolic dimension. We found 16 patients with acute rheumatic carditis, ranging in age from 2.0 to 16.1 years, with just over one-third having symptoms of congestive heart failure. All patients had evidence of acute inflammation. There was a significant relationship between symptoms and severity of mitral regurgitation. No patient had elevated levels of cardiac troponin I level. The fact that levels of cardiac troponin I are not elevated in the serum of children with acute rheumatic carditis suggests that there is minimal myocytic necrosis in this setting. This supports the concept that acute valvar regurgitation is the major hemodynamic abnormality in these patients.

Echocardiographic diagnosis of coronary sinus ostial atresia

Coronary sinus ostial atresia is a rare anomaly that can result in serious hemodynamic sequelae if the decompressing vessel is occluded. Echocardiographic recognition of this malformation in patients with coexistent congenital heart disease before catheterization or surgical intervention may prevent occlusion of the decompressing left superior vena cava.

Intermediate effects of treatment with metoprolol or carvedilol in children with left ventricular systolic dysfunction

The use of beta-blocking agents in adults with congestive heart failure has been shown to improve symptoms and outcome; however, experience in pediatric patients with left ventricular systolic dysfunction is limited. We identified 12 pediatric patients treated with beta-blocking agents for left ventricular systolic dysfunction and reviewed echocardiographic indices of left ventricular systolic performance prior to initiation of beta-blocker therapy and at intermediate follow-up. Left ventricular fractional shortening and ejection fraction increased significantly from baseline to intermediate follow-up (13 +/- 4% to 21 +/- 8% [p = 0.01] and 26 +/- 8% to 41 +/- 17% [p = 0.04], respectively). When added to conventional therapy, beta-blocker therapy resulted in an increase in ejection-phase indices of left ventricular systolic performance at intermediate follow-up in pediatric patients with systolic dysfunction.