A patient presents with LVII. and pulmonary complications. ECG, shows left axis detion. Most likely diagnosis is -

Ans. is 'b' i.e., Tricuspid Atresia Congenital absence of tricuspid valve is called tricuspid atresia. Haemodynamics : The inflow poion of R.V. is hypoplastic The systemic venous blood coming to R.A. exits by way of a patent foramen ovale or an ASD. A VSD provides communication between L.V. and outflow poion of R.V. o The L.V. thus maintains both the systemic and pulmonary circulation. The saturation of blood in the pulmonary aery and aoa is identical --> Because unoxygenated blood from right atrium mixes with oxygenated blood into left atrium. The pulmonary blood flow is dependent on size of VSD --> Smaller the VSD, less the pulmoanry blood flow. Clinical features : Child is cyanotic from bih Anoxic spells and squatting may be present. Features suggestive of tricuspid atresia : a) L.V. type of apical impulse b) Prominent large 'a' waves c) Enlarged liver with presystolic pulsations (a waves) d) ECG characterised by Left axis detion and Left ventricular hyperophy.