ROLE OF EXTENDED FETAL ECHOCARDIOGRAPHY IN DIAGNOSING  TETRALOGY OF FALLOT  IN SOUTHERN  INDIA

DR P.BALAMURUGAN; DR.M. ADAIKAPPAN

Volume : V, Issue : VII, July - 2016

ROLE OF EXTENDED FETAL ECHOCARDIOGRAPHY IN DIAGNOSING TETRALOGY OF FALLOT IN SOUTHERN INDIA

Dr P. Balamurugan, Dr. M. Adaikappan

Abstract :

Aim: To elicit the key points in diagnosing the most common cyanotic prenatal congenital heart disease – Tetralogy of Fallot (TOF) by extended fetal echocardiography and to increase the rate of prenatal detection of Tetralogy of Fallot in a low–risk population. Methods and Material: Our study is a prospective study done at our Fetal Medicine Research centre. During our study we screened about 15000 cases for prenatal congenital heart diseases in low and high– risk pregnancies between 20 and 22 weeks gestation by Extended Fetal echocardiographic examinations over a period of two and half years. Extended Fetal echocardiography includes the four chamber view and visualization of the left ventricular outflow tract(LVOT), the right ventricular outflow tract(RVOT), the main pulmonary artery and its anches by applying M– mode, Doppler and colour doppler techniques. We analyzed the abnormalities seen in various sonographic views. Results: Out of 15000 cases screened by Extended Fetal Echocardiography, 8 cases were diagnosed as typical Tetralogy of Fallot (Absent pulmonary valve syndrome, Pulmonary Atresia , Ventricular septal defect with TOF were excluded ) in low– risk mothers. The average age of the women was 28.25 (range 20 – 37) years. The mean gestational age at the first routine screening was 20.63 (20 –24) weeks; In our study, the specificity of ultrasound in detecting the typical TOF was 100% and also it had a good positive predictive value of 100%. There were no false–positive diagnoses (sensitivity 63.06% to 100.00% at 95% confidence interval, specificity 100%). Conclusions : The main outcome of our Extended Fetal Echo is the detection of all prenatal typical tetralogy of Fallot cases during the second trimester scan(Level 2 scan) by the presence of septo aortic discontinuity , Dilated overriding of aorta and Y sign in Doppler in LVOT view irrespective of low or high– risk pregnancies. We emphasize the value of Extended fetal echocardiography in the prenatal diagnosis of typical tetralogy of Fallot which can improve the neonatal outcomes.