<prompt> Tetralogy of Fallot classically consists of the combination of ail except -Obstruction to right ventricular outflow pulmonary stenosisVentricular septal defect VSDDextroposition of the aorta with septal over-rideLeft ventricular hypertrophy  <response>: Ans. is d i.e., Left ventricular hypertrophy Tetralogy of Falloto TOF is the commonest congenital heart disease.o Constituents of TOF Ventricular septal defect Overriding or dextroposed aorta Pulmonic stenosis Right ventricular hypertrophy. Hemodynamics of Tetralogy of Falloto The severity of obstruction to the right ventricular outflow determines the direction of blood flow. Pulmonary stenosis SevereMildEjection Systolic murmur- Greater resistance to rightThe abnormality resembles anand delay in P2 ventricular outflow throughisolated VSD and the shunt may be pulmonary valveleft to right without cyanosis As this resistance approaches the level of systemic vascular resistance Absence of shunt murmur because-Right to left shunt predominates the pressure difference at which this shunt operates is low Reduced flowr of blood into pulmonary artery i.e. pulmonary artery pressure is reduced Cyanosis and soft P2 Clinical features of TOF:o Dvsnea on exertion and exercise intolerance - Most common,o Cyanosis usually presents after neonatal periodo Hypoxemic or cyanotic spells Tet spellso Commonest congenital lesion with which squatting is usedo Clubbingo Ausculatory findings: S1-Normal S2-Single predominantly Aortic Muimur-Ejection systolic o TOF patients are RARELY CYANOTIC AT BIRTHX-ray findings in TOF Boot shaped heart Cour en sabot Oligemic pulmonary fields Normal sized heart no cardiomegaly 