Phonocardiogram of calcific aortic stenosis as recorded from 2^nd right intercostal space

Electrocardiogram and phonocardiogram of aortic stenosis due to valvular calcification as heard at the 2^nd right intercostal space. S1 (mitral and tricuspid valve closure) is followed by a midsystolic ejection murmur of aortic stenosis. A single S2 is from delayed aortic valve closure that occurs simultaneously with closure of the pulmonic valve.