Fixed splitting of the second heart sound

What it means

Lack of variation in the splitting between the two components of the second heart sound with respiration. Normally, the aortic valve closure (A2) is followed by the pulmonic valve closure (P2) but the A2-P2 interval increases with inspiration and decreases with expiration.

Fixed splitting of S2 may occur in patients with secundum atrial septal defect.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Fixed splitting of S2