Pattern of Congenital Heart Diseases in Children with Congenital Malformations: An Echocardiographic study from a Tertiary Health facility in Sokoto, Nigeria

Background: Children with congenital malformations (CM) may have congenital heart diseases (CHDs) which may be initially asymptomatic. These need to be recognised and managed early in order to reduce unnecessary morbidity in affected patients. We report the pattern of CHDs in children with congenital malformations who had echocardiography over a one year period in UDUTH, Sokoto. Materials and Methods: A cross-sectional study carried out in the Paediatric Cardiology Unit from 1 January to 31 December 2019. Children presenting with CM were recruited and had echocardiagraphic screening for CHDs. Data were analysed with SPSS 23 version. Statistical significance was taken at p < 0.05. Results: 81 children were seen with CM, comprising 42 females and 39 males (M:F=0.93:1); age range of 2 days to 13 years. Most frequent malformationswere anorectal malformations (ARM) in 28 (34.6%), Down syndrome in 17 (21.0%), multiple CM 10 (8.1%) and ocular abnormalities in 4 (4.9%). Thirty two (39.5%) of the patients with CM were diagnosed with CHD, out of which 24 (29.6%) had cardiac murmur. Most frequent CHD was atrioventricular septal defect in 9 (28.1%) followed by ventricular septal defect in 8 (25.0%) and patent arterial duct in 4 (12.5%). CHDs were found in all (100%) those with ocular abnormalities, in 76.5% of Down syndrome and in 14.3% of patients with ARM. Presence of murmur was significantly associated with CHD (χ=18.0; p=0.001; OR=8.2; 95% C.1=2.8 – 24.1). Conclusion: Congenital malformations, particularly Down syndrome and ocular abnormalities, are significantly associated with CHDs. Cardiac murmurs were suggestive of CHD in children with congenital malformations.


Background
Congenital malformations (CM) are structural abnormalities or conditions that arise in the fetus conesquent to preconceptional and intragestational factors and are present at birth, but can also be diagnosed prenatally or much later in life. [1] Congenital malformations are permanent changes produced by an intrinsic abnormality in the development of a body structure prenatally. [1] Congenital malformations can potentially affect the childs health, development and survival because they can be associated with abnormalities in many body systems including congenital heart disease (CHD). [2] Congenital heart diseases (CHD) consist of defects of the cardiac architecture which interfere with the venous drainage, septation of the cardiac segments and their sequences and regular function of the valve apparatuses. [3] Some Congenital malformations may require emergent surgical intervention and the presence of a comorbid cardiac defect may be an anaesthetic risk. [2]Such risks may warrant delay of surgical inteventions if echocardiography is not available to rule out significant CHD. [4]These Screening such children for CHD is therefore important and those conditions more frequently associated with CHD must be recognized clinically by presence or absence of symptoms and signs of cardiac disease. The aim of the study was to ascertain the proportion and types of CHD in children with external Congenital malformations and compare with their cardiac symptoms.

Study design
This study was carried out in the Paediatric Cardiology Unit, Paediatrics department of Usmanu Danfodiyo University Teaching Hospital (UDUTH), Sokoto which is the major tertiary health facility in Sokoto State. The unit receives referrals of children with cardiac conditions from other units within the department and hospital as well as other health facilities within and outside the state and neighbouring border countries in the West African sub-region.
It was a cross-sectional study of children aged 15 years and below presenting to the Paediatric Cardiology Unit between January 2019 to December 2019. Children presenting with external Congenital malformations were recruited and had echocardiagraphic screening for CHDs. Sampling method: Universal sampling method was used.
Inclusion criteria: All children presenting with major external congenital malformations that gave informed consent shall be recruited.
Exclusion criteria: Those who were very ill, limiting full examination for congenital and screening echo. The specific type of Congenital malformations which was the reason for their echo request was additionally confirmed before echocardiography by a complete physical examination.
Echocardiography: Cardiac diagnosis was done using two-dimensional and Doppler transthoracic echocardiography (TTE). Patients were examined in the supine and left lateral positions. The younger ones who were not cooperative were distracted with colourful toys and other techniques with the participation of the parents. The heart was examined through the standard parasternal, apical, subcostal, and suprasternal views using the Hewlett Packard Sonos 5500 echocardiography machine (Bloomfield CT 06002, USA) and 8MHz transducer.
The specific echocardiographic diagnosis was confirmed by 2 or 3 independent echocardiographers with complete agreement in all the cases.
Data Collection: A structured proforma was used to collect their demographic characteristics including age, gender, social status of the parents. The cardiac diagnosis at echocardiography was also recorded.
Ethical issues: Ethical approval for the study was obtained from the Ethics and Research Committee of Usmanu Danfodiyo University Teaching Hospital, Sokoto (UDUTH/HREC/2021/1023/V1) while consent was obtained from the parents of the children. Confidentiality was maintained as well as privacy.

Data Analysis
All relevant data were entered into a proforma sheet then analyzed using SPSS statistical software version 23. Quantitative data were expressed as means and standard deviation while categorical variables were expressed as proportions. Chi-square or where necessary, Fisher's Exact test, was used to test for statistical significance. A p-value of <0.05 was considered statistically significant.

Results
Eighty-one children were seen with external Congenital malformations, comprising 42 females and 39 males (M:F= 0.93:1); age range of 2 days to 13 years.
Most frequent malformations were anorectal malformations (ARM) in 28 (34.6%), Down syndrome in 17 (21.0%), multiple anomalies 10 (8.1%), isolated anomalies 22 (27.1%) and ocular abnormalities (cataract) in 4 (4.9%) (    Table 2 shows there was a high association of CM with CHD in patients with ocular abnormalities and Down syndrome. For those with multiple CM, 50% had CHD, while CHD was completely absent in polydactyly and encephalocele.     The presence of cardiac murmur on auscultation was also examined for association with eventual diagnosis of CHD. Out of the total of 81 patients with CM, 24 (29.6%) had cardiac murmur. Presence of cardiac murmur was significantly associated with CHD (χ 2 = 18.0; p=0.001; OR=8.2; 95% C.1=2.8 -24.1) ( Table 4).  Table 4: Showing the relationsip of presence of cardiac murmur to diagnosis of CHD

Discussion
ARM was the commonest CM presenting for echocardiography in this study and this is consistent with a report by Lawal which was an overview of studies from all over Africa where ARM has been documented to be the most common structural occuring in children. [6] This is unlike the finding in a similar echocardiographic study by Oyati et al from Zaria, Nigeria, [7] located within the same northwestern region as the study area, where cleft lip and palate was the commonest surgical anomaly (38.3%), followed by ano-rectal malformation (26.7%). In this study, cleft lip was seen only in one child co-existing with other multiple major anomalies. The relative paucity of facial clefts among our cohort could be due to the presence of a facility in the study area which is specifically dedicated to catering for congenital and acquired facial clefts. [8] Another study by Ekure [9] showed that Down syndrome as the commonest CM presenting for echocardiography accounting for more than half (53.4%) of those presenting with CM while in this study Down syndrome was the 2 nd commonest indication.
CHD was detected in 39.5% of our cases similar to 35% reported by Oyati. [7] The study by Ekure also showed a much higher figure of 73% having CHD as most of their patient cohort there had recognizable syndromes associated with CHD. [9] The commonest anomaly in our study was AVSD while in the Zaria and Lagos studies, [7,9] it was ASD and VSD respectively reflecting probably the different proportions of the anomalies.
The incidence of CHD in ARM, the commonest CM in this study appeared low (14.3%) compared to other reports like that of Kamal and Azhar [10] who reported the occurrence of CHD in 24.6% patients and Hashemizadeh [10]from Turkey reported 23.7% incidence of CHD among cases of ARM. Two studies from Iran revealed similar higher incidence rate of CHD of 30% and 50.4% in newborns with ARM. [11,12] Half of the patients with ARM in this study had ASD which has also been reported as the most prevalent CHD in those with ARM in other studies as they usually have less of complex CHD. [11,12] This is of import as opined by Nasr et al who examined records to ascertain if routine echocardiography is necessary for all neonates with some CM or if appropriate patients who are not at risk could be selected without preoperative echocardiography. [13] The commonest CHD in those with DS was AVSD which is seen associated with this anomaly in several reports. [14][15][16] Also, all those with ocular anomalies had CHD which wasmainly PDA which could be due to genetic causes. [17][18] Two of the ocular anomalies were cataracts which is associated with Congenital rubella syndrome of which the cardiac component is PDA. A study in Italy has reported significant association between ocular anomalies and CHD. [19] Although, majority of the patients seen were asymptomatic, those who had detectable cardiac murmurs eventually turned out positive for CHD. However, some did not also have any murmur and were diagnosed with complex defects. Some authors have opined for routine screening for all those with CM due to observations of increased morbidity and mortality with combined malformations, [20,21] while others suggest that in emergency conditions, pre-operative echo may not be absolute if not available especially in a CM not commonly associated with CHD. [4] Conclusion: Congenital malformations, particularly Down syndrome and ocular abnormalities, are commonly associated with CHDs. ARM has a relatively low incidence of CHD, which were not complex defects. Cardiac murmurs were suggestive of CHD in children with congenital malformations. However, due to significant number who were asymptomatic that were still diagnosed with CHD, it is importance that all children with CM should be screened for CHD.