PHYLLIS

epidemological_study_of_congenital_heart_disease.pdf

Epidemiological Study of Congenital Heart Disease S.L. C h a d h a , 1 N e e r p a l S i n g h 1 a n d D.K. S h u k l a 2

1Sitaram Bhartia Institute of Science & Research, 2ICMR, New Delhi, India

Abstract. A community based survey of congenital heart disease was carried out on a random sample of 11833 children below 15 years in Delhi, India. Congenital heart disease was diagnosed on clinical history and/or clinical examination. Out of the examined sample, 50 were found suffering from congenital heart disease, giving an overall prevalence of 4.2/1000 (4.6/1000 in boys and 3.7/1000 in girls). The prevalence rate was slightly higher than other studies carded out in the country. The reason is obvious. The present study is community based while other studies were hospital or school based. The type of lesions were similar to those reported from other studies. The lesions in order of frequency were ventricular septal defect (46%), atrial septal defect (18%), patent ductus arteriosus (14%), Fallot's tetrology (10%), aortic stenosis (4%), and pulmonary stenosis (4%). Like other studies ventricular septal defect was the commonest lesion. The prevalence rate was higher in the age group 0-4 years and 5-9 years in boys whereas it was higher in adolescent age group (10-14 years) in girls. [Indian J Pedlatr 2001; 68 (6) : 507-510]

Key wordB : Congenital weart disease; Children below 15 years; Prevalence

Until 1930 it was believed that rheumatic heart disease w a s the m o s t c o m m o n f o r m of h e a r t disease in children. 1 Within recent years, the statistics in m o s t cardiac centres h a v e s h o w n that congenital h e a r t disease is the more c o m m o n of the two. Many cases of congenital h e a r t disease die d u r i n g infancy a n d in some children, the disease does not manifest in the first few years of life, emphasizing the need to establish the prevalence of this disease.

The congenital heart disease has been the subject of i n n u m e r a b l e studies b o t h as regards prevalence a n d clinical features in western countries. The few studies carried o u t in I n d i a w e r e either h o s p i t a l or school based and they did not indicate the m a g n i t u d e of the p r o b l e m . It w a s , t h e r e f o r e , d e c i d e d t o c a r r y o u t c o m m u n i t y b a s e d e p i d e m i o l o g i c a l s t u d y for t h e prevalence of the disease.

MATERIALS AND METHODS

The c o m m u n i t y based study was conducted by house to h o u s e s u r v e y in 1985-87 in a r a n d o m l y selected sample of urban population of Union Territory of Delhi e x c l u d i n g Najafgarh a n d Narela zones w h i c h are considered semi-urban as they have bulk of villages.

Reprint requests : D~ S.L. Chadha, Consultant, Community Health Consultant, Sitaram Bhartia Institute of Science & Re- search, B-16, Mehrauli Institutional Area, New Delhi-110016. E-mail : [email protected]

The list of urban blocks as per 1981 census was used as a sampling frame for the selection of the p o p u l a t i o n sample. O u t of total 8563 u r b a n blocks, 60 w e r e selected r a n d o m l y for the field study. The m e t h o d o l o g y of selection of the r a n d o m i z e d sample was the same as that for e p i d e m i o l o g i c a l s t u d y of coronary heart disease and hypertension in the same population and this is published elsewhere. 2

The urban block was used as a cluster. The d u s t e r size d i d n o t v a r y m u c h a n d c o n s i s t e d o f 120-150 households. The 60 r a n d o m l y selected u r b a n blocks contained 7388 households with a total p o p u l a t i o n of 32376 individuals. Except for 10% n o n - r e s p o n d e n t s / not available, all the children below 15 years available in these families in 60 urban blocks were examined for congenital heart disease. The total n u m b e r of children e x a m i n e d w a s 11833 w h i c h f o r m s t h e b a s i s for calculation of prevalence rates.

Four field survey teams were raised, each consisting of a medical officer with a post-graduate qualification in medicine / pediatrics and a social scientist w i t h a master degree in social work. The survey teams were trained and briefed before starting the actual survey. Suitable forms w e r e d e s i g n e d for collection of data. The social scientists recorded general information e.g., age, sex a n d religion of the child a n d address of the family. The medical officers, r e c o r d e d medical a n d family history of congenital heart disease and also the d e t a i l e d clinical e x a m i n a t i o n of t h e c h i l d r e n w i t h special emphasis o n cardiovascular system.

Indian Joumal of Pediatrics, Volume 68--June, 2001 507

S.L. Chadha et al

Efforts were m a d e to obtain a twelve lead ECG in c h i l d r e n d i a g n o s e d clinically for c o n g e n i t a l h e a r t disease. The diagnosis of the disease was b a s e d o n clinical h i s t o r y a n d / o r clinical e x a m i n a t i o n . The children w h o presented with recurrent chest infections, respfratory distress, cyanotic appearance, poor feeding a n d failure to thrive, were given special attention for diagnosis of congenital heart disease.

RESULTS

The distribution of children examined by age a n d sex is g i v e n in Table 1. O u t of total c h i l d r e n 11833 e x a m i n e d in the age g r o u p 0-14 years, 6238 (52.7%) w e r e boys a n d 5595 (47.3%) girls. The age a n d sex composition of the children was closely similar to that shown by 1981 census population. Table 2 presents age a n d sex specific p r e v a l e n c e rate (per 1000) of congenital heart disease. The disease was detected in 50 children out of 11833 examined giving a prevalence rate of 4.2/1000 in the age g r o u p 0-14 years. The prevalence rate was higher in boys (4.4/1000) than girls (3.7/1000). There was no specific trend in prevalence w i t h age in b o t h sexes. The prevalence in boys was higher in children in the age g r o u p 0-4 years and 5-9 years whereas in girls it was higher in the adolescent age group (10-14 years).

Prevalence of congenital heart disease by religion is given in Table 3. There was no significant difference in the prevalence in the two major communities, H i n d u (4.0 / 1000) and Muslim (3.9/1000). The higher rate in Sikhs a n d Christians is d u e to c o m p a r a t i v e l y small s t u d y sample. Table 4 s h o w s the frequency a n d sex d i s t r i b u t i o n of c o n g e n i t a l h e a r t d i s e a s e . T h e ventricular septal defect (VSD) was the c o m m o n e s t lesion (46~ Atrial septal defect (ASD) was the second c o m m o n e s t c o n g e n i t a l h e a r t d i s e a s e (18%) in o u r s t u d y . P a t e n t d u c t u s a r t e r i o s u s (PDA), F a l l o t ' s tetrology, aortic stenosis and p u l m o n a r y stenosis were detected in 14%, 10%, 4% and 4% cases respectively.

F a m i l y h i s t o r y of c o n g e n i t a l h e a r t d i s e a s e w a s confirmed only in 2 o u t of 50 cases. The response of m o t h e r s of the c h i l d r e n w i t h c o n g e n i t a l disease to antenatal history e.g., history of irradiation or d r u g or hormonal ingestion, exanthematous fever six m o n t h s prior to conception was unreliable to establish possible causative factor.

ECG could be obtained in 43 o u t 50 children w i t h congenital h e a r t disease. ECG w a s w i t h i n n o r m a l limits in 20 cases. The i m p o r t a n t ECG abnormalities detected were right ventricular dominance with sinus tachycardia, right b u n d l e block a n d left ventricular hypertrophy. The ECG h a d therefore limited scope in confirmation of clinical diagnosis.

TABLE 1. Distribution of Children Examined By Age And Sex

Age Group Boys Girls Total (Yrs.) (%) (%) (%)

0-4 2010 1759 3769 (32.2) (31.4) (31.8)

5-9 2187 1885 4072 (35.1) (33.7) (34.5)

10-14 2041 1951 3992 (32.7) (34.9) (33.7)

Total 6238 5595 11833 (52.7) (47.3) (100)

Figures in parentheses indicate percentages.

TABLE 2. Age and Sex Specific Prevalence/1000 of Congenital Heart Disease

Age groups Boys Girls Total Boys & Girls

(Yrs.) No Number Prevalence No. Number Prevale- No. Number Preva- Examined of cases Examined of cases nce Examined of cases lence

0-4 2010 11 5.5 1759 7 3.9 3769 18 4.8 5-9 2187 12 5.5 1885 3 1.6 4072 15 3.7 10-14 2041 6 2.9 1951 11 5.6 3992 17 4.2

0-14 6238 29 4.6 5595 21 3.7 11833 50 4.2

508 Indian Journal of Pediatrics, Volume 68---June, 2001

Epidemiological study of Congenital Heart Disease

DISCUSSION

Prevalence rate of congenital h e a r t disease is n o t k n o w n in our country due to insignificant community b a s e d e p i d e m i o l o g i c a l surveys. The m o s t of the studies carried out are either hospital or school based. The p r e s e n t s t u d y is p r o b a b l y the first of its k i n d carried o u t o n a properly r a n d o m i z e d a n d adequate sample of children. The observed prevalence rate of 4.2/1000 in this s t u d y is comparable to the recorded incidence of 6-8/1000 at birth f r o m d e v e l o p e d countries. 34 The reason for the l o w e r figure for p r e v a l e n c e is quite o b v i o u s as the incidence rate is measured at birth w h e n a n u m b e r o f other congenital heart diseases, some of them incompatible with life, are m o r e frequent than at a later age.

Thakur JS, et al., 5 carried out integrated screening in 15080 school children aged 5-16 years in Shimla hills of n o r t h e r n I n d i a p a r t i c u l a r l y a i m e d at d e t e c t i o n of r h e u m a t i c f e v e r / r h e u m a t i c h e a r t d i s e a s e b u t also p i c k e d u p cases o f c o n g e n i t a l h e a r t d i s e a s e . A prevalence of 2.3/1000 was reported by this study. The s t u d y conducted by Shreshtha NK and Padmavati 6 in Delhi school c h i l d r e n in the age g r o u p 5-16 y e a r s r e p o r t e d prevalence of 3.2/1000 for congenital heart disease. The l o w p r e v a l e n c e in school c h i l d r e n as compared to community based study is obviously d u e to the fact that children u n d e r 5 years d o not attend

school and a large n u m b e r suffering from congenital h e a r t d i s e a s e d i e d u r i n g infancy. V a s h i s t h a e t al, 7 reported prevalence of 5.2/1000 in school children 5-15 years in A g r a city slightly h i g h e r t h a n t h e p r e s e n t study. Like our study, Bidwai et al, 8 a n d J a i n et a U also observed higher prevalence of congenital heart disease in males than female children. These two studies were based entirely on hospital admission data, it is possible the proportion of females admitted to various hospitals is u s u a l l y less t h a n t h e a c t u a l a m o u n t of d i s e a s e prevalent amongst them.

Studies by Shreshtha et al, 6 Vashishtha e t al, 7 Bidwai e t al, 8 & Srivastava S e t al, TM in I n d i a also r e p o r t e d v e n t r i c u l a r septal defect (VSD) as t h e c o m m o n e s t c o n g e n i t a l h e a r t d i s e a s e . F a l l o t ' s t e t r o l o g y w a s reported in 13.6% cases by Vashishtha e t al, while in our study, it was 10%. Atrial septal defect & p a t e n t d u c t u s arteriosus were r e p o r t e d as 23% a n d 11% b y Shreshtha e t al, 6 w h i l e the c o r r e s p o n d i n g figures in o v e r s t u d y w e r e 18% & 14%. O u r f i n d i n g o f p u l m o n a r y stenosis (4%) is in a g r e e m e n t w i t h other Indian studies 8,1~ s h o w i n g 2.8% & 2.9% respectively. The relative rarity of coarctation of aorta a m o n g Indian population is also confirmed by other workers. 8-1~

This study m a y be open to criticism as the diagnosis w a s b a s e d o n clinical h i s t o r y a n d / o r c l i n i c a l e x a m i n a t i o n . The d i a g n o s i s w a s n o t c o n f i r m e d b y cardiac catheterisation a n d / o r surgery. Such invasive

Taste 3. Prevalence of Congenital Heart Disease b y Religion

Religion Number Examined Number of Congenital Prevalence Rate/1000 Heart Disease Cases

Hindu 8914 36 4.0 Muslim 2029 8 3.9 Sikh 797 5 6.3 Christian 86 1 11.6 Others 7 - -

Total 118.33 50 4.2

TABLE 4. Frequency and Sex Distribution of Congenital Heart Disease

Cardiac Lesion Male Female (n-29) (n-21)

Total noSO

No. %

Ventricular Septal Defect (VSD) 14 9 23 46.0 Atrial Septal Defect (ASD) 5 4 9 18.0 Patent Ductus Arteriosus (PDA) 5 2 7 14.0 Fallot's Tetrology 2 3 5 10.0 Aortic Stenosis 1 1 2 4.0 Pulmonary Stenosis 1 1 2 4.0 Dextrocardia 1 1 2.0 Marfan's Syndrome 1 1 2.0

Total 29 21 50 100

Indian Journal of Pediatrics, Volume 68--June, 2001 509

S.L. Chadha et el

p r o c e d u r e s a r e n o t p o s s i b l e i n c o m m u n i t y b a s e d e p i d e m i o l o g i c a l survey. H o w e v e r , the d i a g n o s i s w a s c o n f i r m e d b y p e d i a t r i c i a n / c a r d i o l o g i s t in all cases of c o n g e n i t a l h e a r t d i s e a s e d e t e c t e d . T h e M a y o clinic g r o u p 0I) c o u l d m a k e a complete accurate diagnosis in a b o u t 90% of t h e i r cases w h e t h e r t h e d i a g n o s i s w a s m a d e b y c l i n i c a l m e a n s a n d c a t h e t e r i s a t i o n o r b y catheterisation alone. This g r o u p e v e n s u g g e s t e d t h a t r o u t i n e catheterisation in all cases of congenital h e a r t disease is n o t r e q u i r e d to c o n f i r m the diagnosis. It is possible that children w i t h m i l d p u l m o n i c stenosis a n d atrial septal defect, m a y h a v e b e e n m i s s e d b y clinical e x a m i n a t i o n l e a d i n g t o u n d e r e s t i m a t i o n o f t h e p r e v a l e n c e to s o m e extent.

C O N C L U S I O N

O u r s t u d y s u g g e s t s t h a t a majority of congenital h e a r t d i s e a s e s i n c h i l d r e n m a y r e m a i n u n d e t e c t e d u n l e s s special efforts are m a d e to d i a g n o s e t h e m a n d t h a t v e n t r i c u l a r s e p t a l d e f e c t is t h e h i g h e s t a m o n g s t t h e c h i l d r e n . S c r e e n i n g of c h i l d r e n for c o n g e n i t a l h e a r t d i s e a s e n o t o n l y p r e v e n t s m o r b i d i t y a n d p r e m a t u r e d e a t h s b u t also r e d u c e s the cost of caring patients w i t h c a r d i o v a s c u l a r d i s e a s e s . T h e c h i l d r e n w h o p r e s e n t w i t h r e p e a t e d c h e s t infections, r e s p i r a t o r y distress, cyanotic appearance, p o o r feeding a n d failure to thrive s h o u l d b e specifically e x a m i n e d for c o n g e n i t a l h e a r t d i s e a s e a n d if r e q u i r e d r e f e r r e d for t e r t i a r y care to e n s u r e t i m e l y t r e a t m e n t b y surgical i n t e r v e n t i o n after necessary c o n f i r m a t o r y investigations.

REFERENCES

1. Rauh L.W The incidence of organic heart disease in school children. Am Heart J 1930; 18 : 705-707.

2. Chadha S.L, Radhakrishna S., Ramachandran K, Kaul V and Gopinath N. Epidemiological study of coronary heart disease in urban population of Delhi, Ind J Med Res (B). 1990; 424-430.

3. Keith JD, Rowe RD, Vlad P. Heart Disease in Infancy and Childhood, 3rd edn; New York; Macmilan 1978; 219 : 365-400.

4. Hoffman JIE, Christianson R. Congenital heart disease in a cohort of 19502 births with long term follow up. Am J Cardiology 1978; 42, 641-644.

5. T h a k u r J S e t al. Congenital h e a r t disease a m o n g schoold children in Simla hills. Ind heart Journal 1995; 47 : 232-235.

6. Shrestha N.K. Padmavati S., Congenital heart disease in Delhi school children. Ind J Med Res 1980; 72 : 403- 407.

7. Vashishtha VM cal, Kalra A, Katra K, Jain KK. Prevalence of Congenital heart disease in school children, Indian Paediatr 1993; 30 : 1337-1340.

8. Bidwai PS, Mahajan CM, Walia BVS, Berry JN, Congenital heart disease in childhood, A. clinical study. Ind Paediatr 1971; 10 : 691-694.

9. Jain KK, Sagar A, Beri S, Heart disease in children. Ind Paediatr 1971; 30 : 441-448.

10. Srivastava S, Tandon R, congenital heart disease In : Ahuja MMS, Progress of Clinical Medicine in India, 3rd series, New Delhi 1982; 196-200.

11. Pestana C. Weidman, WH, Swan, I-IJC and Mcgon DS. Accuracy of preoperative diagnosis in congenital heart disease. Am Heart J 1966; 72 : 446.

510 Indian Joumal of Pediatrics, Volume 68---June, 2001

content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's

express written permission. However, users may print, download, or email articles for individual use.