Inferior Vena Cava Diameter Predicts Nephropathy in Patients Late After Fontan Palliation.

Single ventricle congenital heart defect patients have improved survival with Fontan palliation. However, they remain at risk for nephropathy, as indicated by pathologic microalbuminuria. We sought to investigate whether echocardiographic measures of the inferior vena cava diameter (a surrogate for elevated CVP) indexed to the body surface area (iIVC) or cardiac index (CI) can predict the presence of nephropathy in Fontan patients. We performed a single-center case-control study, including 39 asymptomatic Fontan (age 14.8 ± 7.9 years) and 29 healthy controls (age 12.7 ± 2.7 years). The primary outcome was abnormal microalbumin-creatinine ratio (MCR) from the first-morning void urine in Fontan patients. Measurements of iIVC and CI were derived using transthoracic echocardiography by two investigators with a high intra-class correlation coefficient (ICC = 0.97). Group comparison between Fontan and controls as well as between Fontan with normal and abnormal MCR was performed using Fisher's exact and t tests. Pearson and Spearman's correlations and multivariate regressions were performed to analyze the relations between the MCR, iIVC, and CI. Abnormal MCR was noted in 13/39(33%) of Fontan patients. The mean iIVC was larger in the Fontan compared to controls (p < 0.0001) and in Fontan with abnormal MCR compared to those with normal MCR (p = 0.0006). A positive correlation (r = 0.62; p < 0.001) was noted between MCR and iIVC. All patients with abnormal MCR had the iIVC > 1 cm/m2. There were no significant relations between the CI and MCR. Significant prevalence of nephropathy late after Fontan palliation warrents screening. Echocardiographic measurement of iIVC could serve as one of the screening measures. The finding of the iIVC diameter > 1 cm/m2 should prompt further renal evaluation.

Ectopia cordis with a double outlet right ventricle, large ventricular septal defect, malposed great arteries and left ventricular hypoplasia.

Ectopia cordis, defined as partial or complete displacement of the heart outside of the thoracic cavity, is a rare congenital malformation. If not surgically corrected during the early years of life, ectopia cordis can prove to be a fatal abnormality. However, due to the presence of multiple intracardiac and extracardiac malformations, a corrective surgery might not always be successful. The pathology of ectopia cordis with a double outlet right ventricle, large ventricular septal defect, malposed great arteries and left ventricular hypoplasia is discussed, highlighting the complexities involved in such a rare disorder.

Low donor-to-recipient weight ratio does not negatively impact survival of pediatric heart transplant patients.

A major limitation to success in pediatric heart transplantation is donor organ shortage. While the use of allografts from donors larger than the recipient is accepted, the use of undersized donor grafts is generally discouraged. Using the UNOS database, we wanted to evaluate whether using smaller donor hearts affects the short- and long-term survival of pediatric heart transplant patients. A retrospective analysis of data entered into the UNOS database from April 1994 to May 2008 was performed. Pediatric heart transplant recipients (ages 0-18 yr) with DRWR <2.0 were identified and divided into two groups: Low-DRWR (<0.8) and Ideal-DRWR (0.8-2.0). Patients' demographics, pretransplant diagnoses, age at transplantation, severity of pretransplant condition, and rate of complications prior to hospital discharge after transplantation were noted. Fisher's exact, chi-square, and Wilcoxon rank sum tests were used to compare patients' baseline characteristics. Kaplan-Meier curves and Cox proportional hazard regression were used to compare patients' survival and to identify independent risk factors for outcomes. There were 3048 patients (204 with Low- and 2844 with Ideal-DRWR). The Low-ratio group patients were older (8.3 vs. 6.9 yr; p = 0.001), there was a slight male predominance in the Low-DRWR group (p = 0.055). The Low-DRWR group had longer transplant wait time than the Ideal-DRWR group (97 vs. 85 days; p = 0.04). The groups did not differ in race, primary diagnoses, severity of pretransplant condition (medical urgency status, need for ventilation, inotropic support, ECMO, nitric oxide, or dialysis, the PVR for those with bi-ventricular anatomy), or post-transplant complications (length of stay, need for inotropic support, dialysis, and rate of infections). The Low-DRWR patients had less episodes of acute rejection during the first-post-transplant month. Infants with DRWR 0.5-0.59 had lower 30-day survival rate (p = 0.045). There was no difference in short- and long-term survival between the patients with DRWR 0.6-0.79 and DRWR 0.8-2.0. Use of smaller allografts (DRWR 0.6-0.8) has no negative impact on the short- and long-term survival of pediatric heart transplant patients.

Is there a role for intravenous transpulmonary contrast imaging in pediatric stress echocardiography?

OBJECTIVE: Intravenous transpulmonary contrast echocardiography plays a significant role in the enhancement of endocardial border delineation during stress echocardiography in the adult population. The current study was conducted to evaluate the feasibility of intravenous transpulmonary contrast in pediatric patients and to compare the quality of endocardial visualization by harmonic 2-dimensional (2D) imaging alone with harmonic 2D echocardiography with contrast imaging. METHODS: Twenty-two children, age 9.3 +/- 3.9 underwent dobutamine (19 patients) or exercise (3 patients) stress echocardiography. None had intracardiac shunting. Each patient underwent both harmonic 2D imaging alone and harmonic 2D imaging with contrast administration at peak stress. Oxygen saturation, heart rate, and blood pressure were monitored. Endocardial delineation was evaluated by qualitative grading of 22 endomyocardial regional segments in each patient. Contrast images were graded by an echocardiographer who was blinded to the scores previously assigned to harmonic 2D echocardiography images. RESULTS: There were no changes in saturation, heart rate, or blood pressure during or after contrast administration. Use of contrast significantly improved endocardial visualization in 11 of 22 segments (P <.05), particularly lateral, apical, and anterior left ventricular wall segments. CONCLUSION: Intravenous intrapulmonary administration is feasible and has no obvious adverse effects in a small pediatric patient group. Contrast echocardiography improves endocardial border delineation over harmonic imaging in pediatric stress echocardiography.

Sudden intrapartum fetal death in fetuses with absent pulmonary valve syndrome: report of two cases.

Objective To describe potential intrapartum complications for fetuses affected by absent pulmonary valve syndrome. Study Design Two cases of intrapartum fetal death at full term were collected from our institution's labor and delivery unit records. Results In both cases of intrapartum fetal death, the fetuses had been diagnosed with absent pulmonary valve syndrome and had likely experienced acute cardiac events during labor. Both were delivered as stillbirths despite emergency cesarean delivery. Conclusion Patients should be counseled prior to labor about potential intrapartum complications for a fetus with absent pulmonary valve syndrome. Plans for fetal monitoring and the extent of aggressive intervention should be in place before labor in case sudden complications occur.

Nephropathy in patients after Fontan palliation.

UNLABELLED: As the effect of Fontan circulation on the kidneys has not been defined, the purpose of this study was to determine whether it is associated with nephropathy. METHODS: Patients with single ventricle physiology at least 2 years after Fontan procedure with normal cardiac function by echocardiography, history of normal renal ultrasound, and no co-morbidities known to affect the kidneys were evaluated. Patient's demographics, diagnoses, pre- and post-Fontan catheterization data, and current medications were collected. A current glomerular filtration rate (eGFR) was calculated. Morning urine samples were collected for microalbumin/creatinine ratio (MCR). RESULTS: Twenty-one subjects (M:F=13:8, ages 15.2+/-8.8 years) were studied. Primary diagnoses included hypoplastic left ventricle in 9, forms of hypoplastic right ventricle in 10, and unbalanced atrio-ventricular canal in 2 patients. Time after Fontan completion was 11.4+/-6.5 years. Current medications included aspirin (14 patients), coumadin (4), enalapril (8), lisinopril (10), digoxin (11), diuretics (5), and beta-blockers (5). Four subjects had pacemakers. All patients had a normal blood pressure and eGFR. Nine patients (43%) had a pathologic MCR (>20 microg/mg). There were no significant differences between the MCR-normal and MCR-abnormal groups in age, gender, type of single ventricle, type of the procedure, age at or time since Fontan operation. The groups differed in post-Fontan pulmonary vascular resistance (PVR) (p<0.01) and strong positive correlations were found between the MCR and pre- and post-Fontan PVR (r=0.51, p<0.05 and r=0.61, p=0.02 respectively). The MCR-normal and MCR-abnormal groups did not differ in pacemaker, digoxin, diuretics, or anticoagulant use. However, the groups were different in using ACE inhibitors with a negative correlation (r=-0.45, p=0.04) between the MCR and lisinopril-equivalent ACE inhibitor dose. Moreover, no patient receiving a lisinopril-equivalent dose greater than 0.4 mg/kg/day had pathologic microalbuminuria. In conclusion, our study demonstrates that patients with Fontan circulation have high incidence of pathologic microalbuminuria, an indicator of renal injury. The use of ACE inhibitors may be beneficial in preserving their renal function.

Echocardiographic evaluation of pressure gradient across the stent in patients treated for coarctation of the aorta.

OBJECTIVE: Stent placement has become a widely used method of treatment for coarctation of the aorta (COA). Our goal was to find echocardiographic indices that would correlate best with directly measured gradients across the coarctation stent. MATERIAL AND METHODS: Pediatric patients with COA who underwent intra-aortic stent placement were evaluated. Patients with more than mild aortic insufficiency were excluded. Aortic pressures above and below the coarctation site were directly measured in the catheterization laboratory. Echocardiography was performed the next morning. Continuous and Pulse Doppler systolic velocity profiles proximal and distal to the stent were recorded. Statistical analysis included Pearson's correlation coefficients and linear regression between the directly measured pressure gradient and strongest correlated factor. RESULT: Thirty-four patients (F : M = 15 : 19) were included in the study. The directly measured gradients (DPG) had only weak positive correlations with Doppler peak velocities (r = 0.38, P= .027) or pressure gradients (r = 0.37, P= .03) across the stent. However, there was a strong positive correlation of the directly measured gradients with the continuous wave peak systolic velocity half-time indexed to heart rate (T) (r = 0.62, P= .03), and with the squared early diastolic velocity (V(d) (2)) (r = 0.073, P < .0001). When these two parameters were combined, a linear regression equation DPG = 0.06T + 1.58 V(d) (2)- 8.05 showed very strong relations (r = 0.81, P < .0001). A simplified equation DPG = 1.98V(d) (2)+ 0.77 also accurately described the relations between the directly measured gradients and squared Doppler-measured early diastolic velocity (r = 0.71, P= .0002). CONCLUSIONS: A simple echocardiographic index DPG = 1.98V(d) (2)+ 0.77, where DPG is the pressure gradient across the stent, and V(d) is the early Doppler diastolic velocity, accurately describes relations between the gradient across the stent and echocardiographic data and should be used for evaluation of patients with stent-corrected COA.

Left ventricular mechanical synchrony and global systolic function in pediatric patients late after ventricular septal defect patch closure: a three-dimensional echocardiographic study.

BACKGROUND: Patients with large ventricular septal defects (VSDs) undergo surgical patch closure during infancy. The long-term effects of the presence of akinetic patch in the ventricular septum and postoperative right bundle branch block (RBBB) on the left ventricular (LV) mechanical synchrony and global systolic function have not been studied. OBJECTIVE: The objective of this study was to evaluate the long-term effects of an akinetic VSD patch and RBBB on the LV mechanical synchrony and global systolic function in pediatric patients more than 5 years after surgery. METHODS: Eighteen asymptomatic VSD repair and 18 normal control patients were evaluated by an electrocardiogram and three-dimensional echocardiography. Left ventricular end-diastolic volumes (LVEDVs) and volumetric ejection fraction (EF) were calculated. Left ventricular intraventricular synchrony was assessed by the 16-segment volumetric dyssynchrony index. RESULTS: Eight of 18 (44%) patients in the VSD repair group had RBBB. The LVEDV and volumetric EF were similar in the VSD repair and control groups. The LV dyssynchrony index was not significantly different between the VSD repair and control groups (2.46 +/- 1.77% vs. 1.75 +/- 1.08%, P = .16). The VSD repair group was then divided into two subgroups: patients with RBBB (8/18) and those without RBBB (10/18). The two subgroups were similar in demographics, LVEDV, and volumetric EF. However, the RBBB subgroup demonstrated significant LV mechanical dyssynchrony compared with the non-RBBB VSD subgroup (2.70 +/- 1.08% vs. 1.15 +/- 0.35%, P = .006). CONCLUSIONS: Pediatric patients 5-10 years after VSD patch closure have a normal LV function. The presence of the RBBB causes some mechanical dyssynchrony and tendency toward LV dilatation in this group of patients. Therefore, long-term follow-up of these patients is warranted.

Surgical vs. percutaneous atrial septal defect closure: Remote effects on left ventricular diastolic function.

While surgical closure used to be the only treatment for atrial septal defects (ASD), recently, placement of an occluding device has become the treatment of choice for this condition. We sought to study the remote effects of surgical vs. device ASD closure on the indices of left ventricular diastolic function. Forty patients--16 after device and 19 after surgical closure--were evaluated at least 1 year after the procedure. Mitral inflow and tissue Doppler indices were studied. The results were compared to those of 65 control subjects. The early mitral inflow velocities E were higher in controls and E/A ratios were different among all 3 groups. Late diastolic A' TDI velocities were higher in both device and surgical group patients and more different from the controls in surgical than in device group. It appears that surgical ASD closure alters left ventricular diastolic indices more significantly than device ASD closure.

Alternate site atrial pacing in the young: conventional echocardiography and tissue Doppler analysis of the effects on atrial function and ventricular filling.

BACKGROUND: Although the right atrial appendage (RAA) is typically used for atrial pacing lead implant, recent studies have shown benefits of alternate site atrial pacing (ASAP) in the elderly. However, comparable studies in the young are lacking. METHODS: To investigate effects of ASAP on cardiac function and atrioventricular mechanical interactions in the young, 26 subjects (ages 10 to 23 years) with normal cardiac anatomy, function, and atrioventricular node conduction underwent echocardiography during electrophysiology studies while in sinus rhythm (NSR), and with temporary pacing from high right atrium (HRA), RAA, mid septal right atrium approximating Bachmann's bundle (BB), and left atrium (LA) via the distal coronary sinus (CS). After a paced steady state of 10 minutes, left atrial total and systolic ejection fractions, color-guided mitral inflow, and annular tissue Doppler indices were obtained. Left ventricular ejection fraction and myocardial performance indexes (MPI) were calculated. RESULTS: The total and systolic LA ejection fractions were higher during the NSR compared to all ASAP. Mitral inflow velocities changed significantly with ASAP. The passive/active ventricular filling ratio (E/A) deteriorated from NSR to HRA to BB to CS. There were significant changes in late diastolic tissue Doppler velocities during ASAP compared to NSR. The MPI during ASAP differed from those during the NSR. HRA and Bachmann bundle pacing provided better MPIs than RAA or CS pacing. CONCLUSION: The location of atrial pacing leads has an acute impact on cardiac function and atrioventricular mechanical interaction. Pacing close to sinus node location may be beneficial in the young.

Evaluation of left ventricular diastolic function in pediatric sickle cell disease patients.

Although cardiac involvement is common in adult sickle cell disease (SCD) patients, it is unknown when cardiac dysfunction appears in the course of SCD. Diastolic function has not been comprehensively analyzed in children with SCD. Thus, our aim was to evaluate diastolic function in pediatric SCD patients. Echocardiograms were performed in 156 (73 SC and 81 control) patients. Left ventricular and left atrial volumes, left ventricular mass, mitral inflow, and tissue Doppler indices (TDI) were obtained. The right ventricular pressures (RVP) were calculated. For each SCD patient, mean hemoglobin (Hb), fetal hemoglobin (HbF) levels, and blood transfusion encounters were recorded. Data were analyzed using t-test, univariate and multivariate regression, and Spearman correlation analyses. SCD patients had significantly larger left ventricular and atrial volumes than controls. Mitral inflow velocities were significantly higher in the SCD group. Of 73 SCD subjects, 32 had left ventricular dilatation, 11 had hypertrophy, and 25 had elevated RVP. Left ventricular size was inversely related to Hb, but unrelated to HbF or age. The early mitral inflow velocity was correlated negatively with Hb and positively with left ventricular sizes. TDI indices did not differ between the SCD and control groups. They were unrelated to Hg, HgF, transfusion history, or ventricular size; however, Doppler indices of left ventricular stiffness were increased in SCD patients. Pediatric SCD patients demonstrate increased left ventricular stiffness, and a significant percentage of them have left ventricular hypertrophy. There are strong positive relations between left ventricular hypertrophy and right ventricular pressure in these patients. TDI should be employed in the evaluation of SCD patients.