Where is a split S2 best heard on the heart exam?

A split S2 is best heard in the pulmonic area, which is located at the second left intercostal space near the sternum. This phenomenon occurs because the closure of the aortic (A2) and pulmonic (P2) valves does not happen simultaneously during inspiration. Instead, the increased negative intrathoracic pressure during inhalation allows the right ventricle to empty more effectively, causing the pulmonic valve to close slightly later than the aortic valve. This creates the characteristic split sound.

Listening in the pulmonic area provides the clearest and most pronounced split S2, which is a normal physiological occurrence, especially in younger individuals and athletes. It is essential to identify this sound correctly during a cardiovascular examination, as it can provide insights into the patient's hemodynamics and heart function.