Second Heart Sounds Second Heart Sound - Physiologically Split #2 - waveform Lesson Waveform Video play pause Maneuver:Supine Position:Pulmonic Chestpiece:Diaphragm Table of Contents Introduction Second Heart Sound - Physiologically Split #2 Second Heart Sound with Persistent Splitting Second Heart Sound with Fixed Splitting Second Heart Sound: Fixed Splitting, Increased Aortic Intensity Second Heart Sound: Fixed Splitting, Decreased Aortic Intensity Second Heart Sound and Late Systolic Click Second Heart Sound and a Tumor Plop Opening Snap and Second Heart Sound The second heart sound (S2) is created by the closing of the aortic valve followed by the closing of the pulmonic valve. Careful analysis of the splitting and intensity of the second heart sound can indicate the presence of many cardiac abnormalities.This example shows normal physiological splitting of the second heart sound. Splitting varies between zero and eighty milliseconds depending on the phase of the respiratory cycle.The aortic component of S2 (S2A) precedes the pulmonic component (S2P).