Figure 4.
Two consecutive cardiac cycles showing a phonocardiogram waveform along with its four sound phases: S1, systole, S2, and diastole.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.