<prompt> Large PDA leads to ?Endocardial valvulitisEisenmenger syndromeCHFAll of above  <response>: Ans. is d i.e., All of above Patent ductus aeriosus PDA Small PDA may not cause any complication but large defect if untread may leads to : Pulmonary hypeension Left to Right shunt leads to too much circulation of blood in lung which leads to pulmonary hypeension. Eisenmengers syndrome - Large standing pulmonary hypeension leads to permanent lung damage and causes Right to Left shunt. Endocarditis. Arrhythmia Enlargement of hea due to PDA increase risk of arrhythmias 