Duration Of 2nd hea sound is

The second sound lasts about 0.12 s, with a frequency of 50 Hz. It is loud and sharp when the diastolic pressure in the aoa or pulmonary aery is elevated, causing the respective valves to shut briskly at the end of systole Second hea sound is due to sudden closure of semilunar valves at the end of systole. Ref: Ganong's Review of medical physiology 25th edition. Page: 542