<prompt> True about Tetralogy of Fallot TOF are all of the following EXCEPT?It is the most common congenital cyanotic hea disease in childrenSeverity of disease depends on the severity of pulmonary stenosisAtrial septal defect is one of the components of TOFBoot shaped hea is seen on chest X ray  <response>: TETRALOGY OF FALLOT: -- MC congenital cyanotic hea disease in children -- Contain 4 COMPONENTS: 1. Large, unrestricted VSD 2. Pulmonary infundibular stenosis 3. Overriding aoa 4. Right ventricular hyperophy -- CLINICAL FEATURES: Cyanosis Clubbing Polycythemia Cyanotic spells Hea failure is not seen in TOF, unless it is complicated by Anemia Infective endocarditis Myocarditis Systemic hypeension Severity of cyanosis is directly propoional to the severity of pulmonary stenosis; while intensity of murmur is inversly propoional to severity of pulmonary stenosis During cyanotic spell, murmur decreases or becomes absent -Ostium primum type ASD: It is situated in the lower poion of atrial septum and overlies mitral and tricuspid valves. Left axis detion is seen in ostium primum ASD due to RV conduction defect. - Ostium secundum is most common type of ASD - SYNDROMES ASSOCIATED WITH ASD 1. Pierre Robin Sequence 2. TAR Syndrome 3. Fetal Alcohol syndrome 4. Ehler Danlos Syndrome 5. Down Syndrome 6. Holt-Oram syndrome 7. Ellis van Creveld Syndrome 8. Rubinstein Taybi syndrome 