heart sound s1 duration ms code example

Example: types of heart sounds

Valve closure sound- produced at the begining of systole
Valve opening sound
Ventricular filling sound
Extra cardiac sound

1st heart sound:
corresponds to R waves
longer in duration and greater in intensity.
caused at the start of ventricular contraction
frequency-30 to 100 hz

2nd heart sound:
due to closure of aortic and pulmonary(lungs) valves
this is produced at the end of ventricular contraction
frequency above 100 hz

3rd heart sound:
produced by the slight inflow of blood to ventricles 
normally unavailable

4th heart sound :
produced by the contraction of atria