SPECTRUM OF CONGENITAL HEART DISEASES IN BASRA : AN ECHOCARDIOGRPHY STUDY

This is a retrospective study that was set out to describe the spectrum of congenital heart disease using echocardiography in two main centers in Basra over a period of 24 months from June (2006-2008). Children with the diagnosis of congenital heart disease were selected; information obtained from their records included age, gender, clinical diagnosis and chocardiography finding. Five hundred seventy patients had congenital heart disease making 40% of 1414 examined children. There were 309(54%) males and 261(46%) females (ratio 1.2:1); their ages ranged from 3 days to 19 years. Two hundred forty four (42.8%) children referred for echocardiography before the age of one year and two hundred one (35.2%) were 1-4 years of age. Ventricular septal defect was the most common congenital heart disease present in 247 patients (43.3%), of these (81.8%) were membranous in type, 41(16.6%) were muscular, and 4(1.6%) were supracristal type. The second commonest congenital heart disease diagnosed by echocardiography was tetralogy of Fallot in 72(12.6%) of examined children. Sixty eight (11.9%) had atrial septal defects, out of which 55(80.9%) were of secundum type, 7(10.3%) were primum, 5(7.4%) had sinus venosus defect and only one case with coronary sinus defect. Distribution of specific lesions and sex distribution were similar to findings from other parts of the world; However, the overall detection rate at 1 year of age was lower, with increasing availability of echocardiography facilities more cases of congenital heart defects are likely to be identified early.


INTRODUCTION
ongenital heart defects (CHD) represent some of the more prevalent malformations among live births and remained the leading cause of death from congenital malformations. [1,2]CHD defined as an abnormality in cardio circulatory structure or function that is present at birth, even if it is discovered much later. [3]Congenital heart disease occurs in 0.8-1% of live births.The incidence is higher in still births (3-4%), spontaneous abortion (10-25%) and premature infants (2%) excluding patent ductus arteriosus.It has a wide spectrum of severity in infants; about 2-3/1000 newborn infants will be symptomatic with heart disease in the first year of life. [2]CHD causes the deaths of thousands of children in developing countries.According to data from WHO; in north America, heart defects account for more than one third of infant deaths due to congenital anomalies and for approximately one tenth of all infant deaths, these estimate are similar for other areas of the world. [4]Over the past 20-40 years, major advances have been made in the diagnosis and treatment of CHD.Echocardiography is a major mode of cardiovascular imaging with versatile applications, it is a cheap and non invasive technique for the investigation of cardiac diseases with advantage of reproducibility of results, instantaneous images and reliable levels of accuracy. [5]There are limited data on echocardiography findings in children with heart disease in Basra, so this study was set out to describe the spectrum of CHD seen in two echocardiography centers in Basrah city.

PATIENTS AND METHODS
This is a retrospective study; transthorasic echocardiography (TTE) data collected over 24 months (June 2006-June 2008) were reviewed.Patients with ECHO diagnosis of CHD were selected.The study was carried out at Echocardiography Clinic in two main hospitals (Basra maternity and children hospital and Al port hospital).Information obtained from patients records included age, gender, clinical diagnosis and echocardiography findings.The presence and severity of any cardiac malformation was analyzed according to recommendations of the American Society of Echocardiography. [6]Presence of atrioventricular septal defect (AVSD) was determined as either complete if a single common atrioventricular valve was present or partial if both atrioventricular valves (mitral and tricuspid) were seen with primum atrial septal defect, inlet ventricular septal defect or cleft anterior leaflet of mitral valve the patient was placed under the dominant defect.All cyanotic CHD except tetralogy of Fallot (TOF) and transposition of great arteries (TGA) were categorized as complex CHD, which included C common arterial trunk, double outlet ventricles, double inlet ventricles, hypoplastic right ventricle, hypoplastic left ventricle, atrioventricular valve atresia and anomalous venous connections.The miscellaneous group included all acyanotic CHD that could not be categorized into one of the other groups.Persistent foramen ovale in the neonate and patent ductus arteriosus (PDA) in premature babies were not included in the analysis, however these were considered if they persisted beyond the first four weeks of life.Echocardiographic modalities applied included M mode, two dimensional and Doppler echocardiography were done with 3 and 7 MHz sector transducer.The data were analyzed using SPSS version 10 soft ware.

RESULTS
A total of 1414 echocardiography examinations were done over 24 months, five hundred seventy (40%) patients had CHD.There were 309 males and 261 females (ratio 1.2:1), their ages ranged from 3 days to 19 years.The mean age was (2.68±3.37)years.The distribution of CHD in general was almost predominance for male with VSD, TOF, ASD, D-TGA while females with PDA were predominant.

DISCUSSION
This study highlights the common variants of CHD seen in Basrah.The presence and severity of any cardiac malformation was analyzed with similar approach had been followed in American Society of Echocardiography [6] and other studies. [7,8] CHD.12] In other reports the diagnosis of CHD is established by one week of age in 40-60% of patients and by one month of age in 50-60%. [2,13]Unfortunately; this is the scenario that operates in most developing countries because of the lack of skilled personal, equipment and facilities for diagnosis.Patients presented for echocardiography for the first time at late age in about (22%) in this study, probably due to difficulties in accessing care; neglect of the family to search early medical help.There was a slight male predominance; this is consistent with reports from Mahaud et al, [9] Al-abdulgader and Reinvold. [14,15]The distribution of males with CHD suggest an important causative link that is not well understood.When all isolated lesions are classified by embryonic timing of disturbed organogenesis, male had to predominate in those that are developed later in gestation. [16]Acyanotic CHD was more common than cyanotic CHD, the relative frequencies of individual CHD are consistent with reports from Nigeria, [17,18] Saudi Arabia [14] and other parts of the worlds [2] With VSD being the commonest acyanotic lesion and TOF was the second most common cyanotic lesion in this series, this is consistent with other reports. [2,9]Concerning cyanotic CHD; TOF constitutes 12.6% of all CHD in Basrah, other study conducted in Nigeria reported a higher frequency 26.2%. [9]chocardiography definition of TOF is still lacking as some authors still consider double outlet right ventricle with pulmonary stenos is as TOF, even if most of aortic emanates from right ventricle, this will exaggerate the frequency of TOF.On the other hand still lower frequency of TOF recorded in Saudi Arabia 3.5% [14] and in Japan 5.8% [19] Atrial septal defect was the third most frequent lesion 11.9% compared to 5.3% in Calfornia [20] and 12.3% in Nigeria. [9]Ostium secundum defect being most common type of ASD worldwide. [2]The frequency of PDA was 6.8% overall, excluding PDA of premature neonate. [2]In this series; it was 9.4%, changing frequency in different reports may be attributed to differences in definition of CHD, study methodology and diagnostic accuracy with emphasis on certain exclusion has significant impact on accurate calculation of the real frequency of PDA.Atrioventricular septal defect, a characteristic lesion of Down syndrome, accounted for 6.4% of all CHD, fluctuations of its frequency in different studies is well known, 3.5% in Saudi Arabia [14] and 8.2% in Nigeria. [9]Transposition of great arteries was found with a higher frequency in this study compared to other studies done by Alabdalghadar et al (2.1%) in Saudi Arabia [14] and Hoffman (2.6%) in USA. [20]The presence of environmental causative factors might have contributed to high frequency of TGA in Basrah, it had been suggested that the interaction between genetic and environmental factors plays a major role in its etiology. [21]Also it shows a male predominance; which was first noted by MacMahon et al. in 1953 [22] and has been supported by number of subsequent studies. [23]egarding obstructive lesion of pulmonary artery and aorta it had been recorded with lower frequency; in contrast to other studies in Japan, [19] USA [20] and Saudi Arabia. [14]With advances in both palliative and corrective surgery in the past 20 years in developed countries, the number of children with CHD surviving to adulthood has increased dramatically, however; despite these advances, CHD remain the leading cause of death in children with congenital malformations. [2]Only 40% of referred children with suspected heart disease had a congenital heart disease, this burden of unnecessary referrals could be minimized by improving clinical skills for recognizing these conditions.Pediatric echocardiography as diagnostic tool should be made more widely available especially in tertiary institutions to enable early diagnosis and, screening for possible cardiac defects using echocardiography during pregnancy, this can improve the outcome of some fetuses with severe cardiac malformations.parents who have a child with CHD require genetic counseling regarding the probability of cardiac malformation occurring in subsequent children.There is an urgent need for the government to establish pediatric cardiac surgical centers with specialized medical cardiology, intensive care, imaging and interventions.

Table 1 ,
Illustrates the age and sex distribution of the patients.Two hundred forty four (42.8 %) children were less than one year old and 445(78%) under 5 years.