A systematic review of trends and patterns of congenital heart disease in children in Nigeria from 1964-2015

BACKGROUND

Congenital heart diseases cause significant childhood morbidity and mortality. Several restricted studies have been conducted on the epidemiology in Nigeria. No truly nationwide data on patterns of congenital heart disease exists.

OBJECTIVES

To determine the patterns of congenital heart disease in children in Nigeria and examine trends in the occurrence of individual defects across 5 decades.

METHOD

We searched PubMed database, Google scholar, TRIP database, World Health Organisation libraries and reference lists of selected articles for studies on patterns of congenital heart disease among children in Nigeria between 1964 and 2015. Two researchers reviewed the papers independently and extracted the data. Seventeen studies were selected that included 2,953 children with congenital heart disease.

RESULTS

The commonest congenital heart diseases in Nigeria are ventricular septal defect (40.6%), patent ductus arteriosus (18.4%), atrial septal defect (11.3%) and tetralogy of Fallot (11.8%). There has been a 6% increase in the burden of VSD in every decade for the 5 decades studied and a decline in the occurrence of pulmonary stenosis. Studies conducted in Northern Nigeria demonstrated higher proportions of atrial septal defects than patent ductus arteriosus.

CONCLUSIONS

Ventricular septal defects are the commonest congenital heart diseases in Nigeria with a rising burden.

Differential Impact of Pulmonary Regurgitation on Patients With Surgically Repaired Pulmonary Stenosis Versus Tetralogy of Fallot

Patients with repaired pulmonary stenosis (PS) or tetralogy of Fallot (TOF) both develop pulmonary regurgitation (PR) leading to right ventricular (RV) dilatation and dysfunction. We aimed to characterize differential effects of chronic PR in these populations. Patients with surgically repaired PS were matched 1:2 by age and PR fraction with patients with TOF. Patients with previous pulmonary valve replacement were excluded. Cardiovascular magnetic resonance data were compared; peak longitudinal and circumferential systolic strain by feature tracking were compared to evaluate differential contribution of the RV sinus and outflow tract, respectively. PS (n = 24, 41 ± 13 years old) and TOF (n = 47, 39 ± 13 years old) patients did not differ in RV end-diastolic volume (153 ± 45 vs 154 ± 45 ml/m(2), p = 0.99) or diastolic function. However, patients with PS had preserved RV ejection fraction (54.3 ± 4.4% vs 48.0 ± 7.1%, p <0.0001). Differences were greater in RV circumferential (-15.8 ± 3.3 vs -11.8 ± 3.4, p <0.0001) than longitudinal strain (-18.0 ± 3.8 vs -15.9 ± 3.8, p = 0.04), with particular decrease in the infundibulum (-17.4 ± 7.5 vs -6.8 ± 6.3, p <0.0001). Late gadolinium enhancement in the RV outflow tract was more frequent in patients with TOF (70.2% vs 45.8%, p = 0.001). In conclusion, surgical repair of PS leads to similar RV dilatation and diastolic dysfunction compared to patients with TOF, but differential effects on ventricular systolic function, largely related to differences in the outflow tract. With different patterns of scarring and ventricular remodeling, further study is needed to clarify whether criteria for pulmonary valve replacement in patients with PS should differ from those with TOF.

MICRODUPLICATION OF 17p[DUP(17)(12p11.2)]: REPORT OF A NEONATE WITH A SPINA BIFIDA AND CARDIAC ANOMALIES AND A LITERATURE REVIEW

Duplication 17pll.2 syndrome is a recent recognized syndrome with multiple congenital anomalies and mental retardation. Most patients with duplication 17p11.2 syndrome harbor a common 3.7 Mb duplication (17p.11.2 duplication syndrome) resulting in congenital anomalies, neurodevelopmental and behavioral phenotypes. We report a case with spina bifida, tetralogy of Fallot and a small duplication (932 Kb) of 17pl1.2 containing approximately 20 genes, detected by array-CGH. We describe clinical features not reported previously for microduplication of 17p11.2.

[Uncorrected Tetralogy of Fallot--a case report of a 69-year-old patient]

Tetralogy of Fallot (ToF) is the most common cyanotic congenital heart defect. The actual treatment relies on cardio-surgery--complete correction within the infant age. Without surgery only 10% of subjects survived 3rd decade and only 3-5% of subjects were able to survive until their 40th. This particular paper is dedicated to case of a 69-years old male subject with positive history of uncorrected ToF due to his refusal of surgery, ischemic cardiac disease NYHA III-IV and chronic kidney failure. This subject was hospitalized within the department of internal medicine due to several days of chest pain connected with lower extremities oedemas and dyspnoeic syndrome after minimal physical load. Provided echocardiography revealed pulmonary artery stenosis, severe tricuspid insufficiency, concentric hypertrophy of ventricles, ventricular septal defect, dextroposition of aorta and severe pericardial effusion. Chest X-ray proved massive pleura effussion. The actual conditions of subject improved significantly after onset of diuretics, antiarrhytmics and providing of pleural punction. Subject has been discharged. Cases of ToF presented within available sources in older population were associated with left ventricular hypertrophy and hypoplastic pulmonary artery and slow subpulmonal obstruction development which also presented within our subject. Left ventricular hypertrophy has a potential to develop continuously and therefore its benefits can be visible within adult age.

Incremenal Value of Cardiac Magnetic Resonance for Assessing Pulmonic Valve Regurgitation

BACKGROUND AND AIM OF THE STUDY

Cardiac magnetic resonance (CMR) is the 'gold standard' for quantifying pulmonic regurgitation (PR) in adults with congenital heart disease, but remains costly and is less readily available than echocardiography. Qualitative echocardiographic assessment of PR is challenging, and guiding criteria are limited. It is unknown if echocardiography is sufficient to screen for significant PR. The study aim was to determine whether cardiac MRI provides additional benefit in the assessment of PR in adults with congenital heart disease.

METHODS

Patients with repaired tetralogy of Fallot or congenital pulmonic stenosis after valvotomy undergoing transthoracic echocardiography and CMR with no interval intervention were identified from a prospective registry. Patients with greater than mild pulmonic stenosis, residual ventricular septal defect or poor echocardiographic windows were excluded. Whole-cohort and subgroup (tetralogy of Fallot versus pulmonic stenosis) analyses for inter-modality agreement were performed.

RESULTS

A total of 48 patients (24 men, 24 women; mean age 43 +/- 12 years) was included in the analysis. The unweighted kappa value for the two modalities was 0.30, suggesting 'fair' agreement, though only 52% had matching PR assessments. The indexed right ventricular end-systolic volume (RVESVi) correlated closely with cardiac MRI-monitored PR (p = 0.011 by analysis of variance), but not with that monitored with echocardiography (p = 0.081). Subgroup analysis demonstrated less inter-modality agreement in the tetralogy of Fallot population (kappa 0.25) than in the pulmonic stenosis population (kappa 0.35).

CONCLUSION

CMR measurement of PR correlates closely with the RVESVi, and appears superior to echocardiography when assessing patients at risk for PR. The study results suggest a vital role for CMR whenever significant PR is suspected in the adult congenital heart disease population.

Tetralogy of Fallot presenting with Right Ventricular Failure

A 32 year old male patient was admitted with exertional dyspnea for long duration with features of right sided failure. On examination, it seemed to be a congenital cyanotic heart disease with decrease pulmonary flow. Echocardiography showed a malaligned VSD with pulmonary stenosis with severe AR and the total regurgitation volume was going to the RV instead of going to both the ventricles leading to dilatation of right ventricle and failure.

Right ventricular volumes assessed by echocardiographic three-dimensional knowledge-based reconstruction compared with magnetic resonance imaging in a clinical setting

OBJECTIVES

A technique that uses two-dimensional images to create a knowledge-based, three-dimensional model was tested and compared to magnetic resonance imaging.

BACKGROUND

Measurement of right ventricular volumes and function is important in the follow-up of patients after pulmonary valve replacement. Magnetic resonance imaging is the gold standard for volumetric assessment. Echocardiographic methods have been validated and are attractive alternatives.

METHODS

Thirty patients with tetralogy of Fallot (25 ± 14 years) after pulmonary valve replacement were examined. Magnetic resonance imaging volumetric measurements and echocardiography-based three-dimensional reconstruction were performed. End-diastolic volume, end-systolic volume, and ejection fraction were measured, and the results were compared.

RESULTS

Magnetic resonance imaging measurements gave coefficient of variation in the intraobserver study of 3.5, 4.6, and 5.3 and in the interobserver study of 3.6, 5.9, and 6.7 for end-diastolic volume, end-systolic volume, and ejection fraction, respectively. Echocardiographic three-dimensional reconstruction was highly feasible (97%). In the intraobserver study, the corresponding values were 6.0, 7.0, and 8.9 and in the interobserver study 7.4, 10.8, and 13.4. In comparison of the methods, correlations with magnetic resonance imaging were r = 0.91, 0.91, and 0.38, and the corresponding coefficient of variations were 9.4, 10.8, and 14.7. Echocardiography derived volumes (mL/m(2)) were significantly higher than magnetic resonance imaging volumes in end-diastolic volume 13.7 ± 25.6 and in end-systolic volume 9.1 ± 17.0 (both P < .05).

CONCLUSIONS

The knowledge-based three-dimensional right ventricular volume method was highly feasible. Intra and interobserver variabilities were satisfactory. Agreement with magnetic resonance imaging measurements for volumes was reasonable but unsatisfactory for ejection fraction. Knowledge-based reconstruction may replace magnetic resonance imaging measurements for serial follow-up, whereas magnetic resonance imaging should be used for surgical decision making.

Moving towards universal prenatal detection of critical congenital heart disease in southern Nevada: a community-wide program

This study compares the current, prenatal detection rate for critical congenital heart disease in Southern Nevada with the previously reported rate, after developing and expanding a comprehensive, community-wide fetal cardiology program. For the current-period analysis, we inquired our database and electronic health records for patients born in Clark County, Nevada, with critical congenital heart disease between May 2012 and April 2014, and we compared the results with the previous period between May 2003 and April 2006. The major components of the community-wide program include fetal congenital heart disease screening via general obstetric ultrasound studies performed in obstetrician's offices, radiology imaging centers, or maternal-fetal medicine specialty practices; subsequent referral for comprehensive fetal echocardiography performed in maternal-fetal medicine offices under the on-site supervision by fetal cardiologists; and recurring community educational programs teaching the 5-axial plane, fetal echocardiographic screening protocol to general obstetric sonographers and instructing perinatal sonographers in advanced imaging topics. For the current period, the prenatal detection rate for critical congenital heart disease in Southern Nevada was 71 versus 36% for the previous period (p < 0.001). The temporal improvement in prenatal detection of critical congenital heart disease may be related to our expanded decentralized, community-wide fetal cardiology program, and our experiences may be applicable to other metropolitan areas.

Relation of right ventricular mass and volume to functional health status in repaired tetralogy of Fallot

After repair of tetralogy of Fallot, right ventricular (RV) mass and mass:volume ratio may reflect RV remodeling and adverse outcomes. This study aimed to evaluate the relation of RV mass to functional health status and subsequent adverse RV remodeling and to determine whether RV mass measurement in systole could improve reproducibility. In 53 patients with tetralogy of Fallot (median 29 years old) who previously underwent cardiovascular magnetic resonance and completed the Short Form 36, version 2 (Optum, Eden Prairie, MN), short-axis images were analyzed for RV end-diastolic volume and diastolic and systolic mass, indexed to body surface area. The most recent subsequent cardiovascular magnetic resonance study (before pulmonary valve or conduit replacement) was evaluated for change in RV end-diastolic volume and ejection fraction. Diastolic indexed mass ≥37.3 g/m(2) (odds ratio 7.6, p = 0.02) predicted decreased general health scores. In patients with normal RV ejection fraction, indexed mass correlated with Physical Component Summary and general health scores. RV diastolic mass:volume ratio >0.2 had a strong association with subsequent increase in RV end-diastolic volume (odds ratio 26.1, p = 0.002). Systolic RV mass measurement had excellent correlation with diastolic measurement (r = 0.97, p <0.0001), but did not improve intraobserver or interobserver variability. In conclusion, RV mass relates to functional health status and adverse RV remodeling and can be measured with good reproducibility. RV mass should be routinely evaluated in this population and is best measured in diastole; further study is necessary to evaluate longitudinal changes in functional health status and RV parameters.

Importance of absent ductus arteriosus in tetralogy of Fallot with absent pulmonary valve syndrome

Tetralogy of Fallot without pulmonary valve syndrome is almost always associated with an absent ductus arteriosus. Patients with right aortic arch and retroesophageal left subclavian artery have a vascular ring if the left ductus arteriosus or its remnant and the Kommerell diverticulum are present. We report the cases of 2 infants in whom the role of an absent ductus arteriosus or its remnant is noteworthy. Both patients had a combination of tetralogy of Fallot with absent pulmonary valve syndrome and right aortic arch with retroesophageal left subclavian artery without a vascular ring. The absence of the ductus arteriosus has a role in the pathogenesis of tetralogy of Fallot with absent pulmonary valve syndrome. The absence of a ductus arteriosus in the right aortic arch with retroesophageal left subclavian artery precludes a vascular ring.

Unusual retinal abnormalities in sisters with tetralogy of Fallot

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease and can occur in the setting of chromosomal aberrations or multisystem malformation syndromes. We report unusual focal bilateral retinal defects in sisters with TOF.

Usefulness of magnetic resonance imaging to guide referral for pulmonary valve replacement in repaired tetralogy of Fallot

The aim of this study was to determine if adult patients with repaired tetralogy of Fallot are being referred for pulmonary valve replacement (PVR) earlier on the basis of cardiac magnetic resonance imaging (CMR) parameters despite the absence of CMR-based recommendations in the American College of Cardiology and American Heart Association joint guidelines. Variables defined by the guidelines were analyzed in conjunction with CMR-based parameters across 3 groups defined by the release of the guidelines: (1) patients referred before the guidelines, (2) patients referred 0 to 3 years after the guidelines, and (3) patients referred ≥3 years after the guidelines. Seventy-nine patients were identified. No significant trend was observed in guideline-defined variables. Significant trends in indexed right ventricular end-diastolic volume (p = 0.034), indexed right ventricular end-systolic volume (p = 0.001), and the right ventricular ejection fraction (p = 0.005) were observed across groups. By multivariate regression, patients who underwent PVR ≥3 years after the release of the guidelines had a 29 ml/m(2) smaller indexed right ventricular end-diastolic volume (p = 0.01) and a 33 ml/m(2) smaller indexed right ventricular end-systolic volume (p <0.001) compared with patients who underwent PVR before the release of the guidelines. PVR 0 to 3 years after the guidelines was not a significant predictor of either indexed right ventricular end-diastolic volume (p = 0.93) or indexed right ventricular end-systolic volume (p = 0.18). Patients referred for PVR ≥3 years after the guidelines had significantly smaller CMR-based right ventricular volumes without significant trends in guideline-defined variables. Given the increased use of CMR to guide PVR referral, revisiting the guidelines to address appropriate use of CMR derived thresholds is indicated.

High-resolution 3-dimensional late gadolinium enhancement scar imaging in surgically corrected Tetralogy of Fallot: clinical feasibility of volumetric quantification and visualization

BACKGROUND

The extent of surgical scarring in Tetralogy of Fallot (TOF) may be a marker of adverse outcomes and provide substrate for ventricular arrhythmia. In this study we evaluate the feasibility of high resolution three dimensional (3D) late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) for volumetric scar quantification in patients with surgically corrected TOF.

METHODS

Fifteen consecutive patients underwent 3D LGE imaging with 3 Tesla CMR using a whole-heart, respiratory-navigated technique. A novel, signal-histogram based segmentation technique was tested for the quantification and modeling of surgical scar. Total scar volume was compared to the gold standard manual expert segmentation. The feasibility of segmented scar fusion to matched coronary CMR data for volumetric display was explored.

RESULTS

Image quality sufficient for 3D scar segmentation was acquired in fourteen patients. Mean patient age was 32.2 ± 11.9 years (range 21 to 57 years) with mean right ventricle (RV) ejection fraction (EF) of 53.9 ± 9.2% and mean RV end diastolic volume of 117.0 ± 41.5 mL/m². The mean total scar volume was 11.1 ± 8.2 mL using semi-automated 3D segmentation with excellent correlation to manual expert segmentation (r = 0.99, bias = 0.89 mL, 95% CI -1.66 to 3.44). The mean segmentation time was significantly reduced using the novel semi-automated segmentation technique (10.1 ± 2.6 versus 45.8 ± 12.6 minutes). Excellent intra-observer and good inter-observer reproducibility was observed.

CONCLUSION

3D high resolution LGE imaging with semi-automated scar segmentation is clinically feasible among patients with surgically corrected TOF and shows excellent accuracy and reproducibility. This approach may offer a valuable clinical tool for risk prediction and procedural planning among this growing population.

Long-term follow-up after pulmonary valve replacement in repaired tetralogy of Fallot

Surgical pulmonary valve replacement (PVR) in previously repaired tetralogy of Fallot (TOF) is frequently required. There are few data in large series of patients with long-term follow-up. Our aim was to review our 40-year experience with PVR after TOF repair and to evaluate prognostic factors for reintervention and death. Between 1973 and 2012, 278 patients with repaired TOF (53% men; 31.4 ± 16.4 years) underwent first PVR 24 ± 13 years after TOF repair. Three or more previous operations were performed in 17% of the patients, and 42% were in New York Heart Association (NYHA) class III/IV. PVR types included porcine (n = 211), pericardial (n = 37), homograft (n = 27), and mechanical (n = 3). Early mortality was 1.4%. Mean follow-up was 7.3 ± 6.8 years (maximum, 34 years). Overall survival at 5, 10, and 15 years was 93%, 83%, and 80% compared with 99%, 97%, and 95% in a gender- and age-matched US population, p <0.001. Independent risk factors for death were older age at complete repair (hazards ratio [HR] 1.2, p = 0.012), ≥ 3 previous cardiac operations (HR 1.9, p = 0.019), NYHA class III/IV at PVR (HR 2.7, p = 0.019), and large body surface area at PVR (HR 1.9, p <0.001). Reintervention after initial PVR occurred in 25 patients. Overall 5, 10, and 15 years freedom from pulmonary valve reintervention was 97%, 85%, and 75%, respectively. Multivariate analysis demonstrated older age at PVR to be protective from reintervention (HR 0.7, p <0.001). In conclusion, PVR is a safe operation with a low rate of reintervention in repaired TOF. The total number of cardiac operations, surgical timing, and the NYHA classification before PVR are important prognostic factors.

Factors associated with right ventricular dilatation and dysfunction in patients with chronic pulmonary regurgitation after repair of tetralogy of Fallot: analysis of magnetic resonance imaging data from 218 patients

OBJECTIVE

The aim of the present study was to identify the factors associated with right ventricular (RV) dilatation and dysfunction in patients with chronic pulmonary regurgitation (PR) after repair of tetralogy of Fallot.

METHODS

From April 2002 to June 2013, 218 patients with repaired tetralogy of Fallot underwent magnetic resonance imaging; 165 (76%) underwent transannular repair and 36 (17%) underwent nontransannular repair. Linear regression analyses were used to identify the predictors for RV end-diastolic volume index (EDVI), end-systolic volume index (ESVI), and ejection fraction.

RESULTS

On univariable analysis, male sex, ventricular septal defect (VSD) closure through the right ventricle, larger pulmonary artery index, and greater PR fraction were associated with greater RV volume indexes. Multivariable analyses identified male sex (β = 17.55, P < .001 for RV EDVI; β = 14.08, P = .001 for RV ESVI), VSD closure through RV (β = 8.49, P = .048 for RV ESVI), longer interval since repair (β = 1.29, P = .014 for RV EDVI), and greater PR fraction (β = 1.92, P < .001 for RV EDVI; β = 1.38, P < .001 for RV ESVI) as independent predictors for greater RV volume indexes. On univariable analysis, male sex, VSD closure through the right ventricle, and greater PR fraction were associated with a lower RV ejection fraction. Multivariable analysis identified male sex (β = -3.10, P = .018), VSD closure through the right ventricle (β = -3.05, P = .020), and greater PR fraction (β = -0.27, P < .001) as independent predictors for a lower RV ejection fraction.

CONCLUSIONS

Male sex, VSD closure through the right ventricle, longer interval since repair, and greater PR fraction were independent predictors of RV dilatation after tetralogy of Fallot repair. Male sex, VSD closure through the right ventricle, and greater PR fraction were also independent predictors of RV dysfunction.

Unusual clinical presentation of rare adult survivors with a missing pulmonary valve associated with a missing left pulmonary artery

Tetralogy of Fallot with absent pulmonary valve syndrome is associated with absence of the left pulmonary artery in one-seventh of cases. Infants with this disorder commonly present very early in life with respiratory distress and heart failure. Because the pulmonary blood flow is primarily to the right lung only, severe respiratory distress occurs. Survival to late childhood without surgery is very rare due to clinical worsening in infancy. This report describes two adult natural survivors with this rare association who presented with extremely unusual unreported clinical features. The aneurysmally dilated main pulmonary artery was compressed on the left coronary ostium, causing angina in the first patient. The second patient had recurrent ventricular tachycardia originating from the dilated thinned out right ventricular outflow tract. Both patients had successful surgical correction with valved xenograft conduits.

Regional manifold learning for disease classification

While manifold learning from images itself has become widely used in medical image analysis, the accuracy of existing implementations suffers from viewing each image as a single data point. To address this issue, we parcellate images into regions and then separately learn the manifold for each region. We use the regional manifolds as low-dimensional descriptors of high-dimensional morphological image features, which are then fed into a classifier to identify regions affected by disease. We produce a single ensemble decision for each scan by the weighted combination of these regional classification results. Each weight is determined by the regional accuracy of detecting the disease. When applied to cardiac magnetic resonance imaging of 50 normal controls and 50 patients with reconstructive surgery of Tetralogy of Fallot, our method achieves significantly better classification accuracy than approaches learning a single manifold across the entire image domain.

Tetralogy of Fallot in a 6-year-old albino ferret (Mustela putorius furo)

Tetralogy of Fallot associated with bidirectional shunting across a large ventricular septal defect, was found in a 6-year-old ferret. The prognosis associated with tetralogy of Fallot is usually poor. This case is interesting given the advanced age of the ferret. The bidirectional shunting, responsible for an acyanotic disease, may explain the unexpected prolonged survival in this ferret.

Routine primary repair of tetralogy of Fallot in the neonate

Uncertainty surrounds both the timing and ideal form of early management of tetralogy of Fallot. Some centers perform early complete repair in all patients regardless of age, symptoms and morphology. Others recommend a two-stage approach involving initial palliation in symptomatic neonates and young infants and those with unfavorable anatomy (anomalous coronary anatomy or hypoplastic pulmonary arteries). Advantages of early anatomic correction include alleviation of cyanosis, normal growth and organ development, removal of stimulus for right ventricular hypertrophy and avoidance of risks associated with initial palliation. With recent advances in anesthetic, operative and postoperative management, routine primary repair of tetralogy of Fallot in the neonate and young infant can be accomplished with excellent early and mid-term results. However, long-term follow-up is necessary to assess the impact of early repair on late right ventricular function, arrhythmias and need for reintervention.

Chronic pulmonary valve insufficiency after repaired Tetralogy of Fallot: diagnostics, reoperations and reconstruction possibilities

Complete correction of Tetralogy of Fallot, the most common cyanotic congenital heart defect, has now become routine. However, late residual lesions, primarily chronic pulmonary valve insufficiency, may have a negative impact on right-ventricular function, leading to the need for reoperation to insert a competent valve at the right-ventricular outflow. The diagnostic modalities pertaining to the failing right ventricle, the timing for eventual reintervention and the various surgical reconstruction possibilities of the right-ventricular outflow tract are still controversial and evolving, and are reviewed with a brief overview on current trends and future outlooks.