Describe Splitting sequence of S2 ?
Even though the pulmonary valve closes at about 20 mm Hg and aortic valve at 100 mm Hg, the aortic closure occurs first as the impendence to forward flow is less in pulmonary circuit (pulmonary vascular resistance is about 1/10th of systematic vascular resistance). Also the elastic recoil of normal pulmonary artery is less than that of + aorta (hang out time).