This disease used to be diagnosed after the rupture of an aneurysm, but recently, unruptured aneurysms of the sinus of Valsalva appear to be detected incidentally by imaging modalities.
Below is three-dimensional CT images of an unruptured Valsalva aneurysm. You can see a sack-like structure attached to the right coronary cusp; three arteries are the right coronary artery, the left anterior descending artery, and the left circumflex artery.
Surgical repair is recommended for a ruptured Valsalva aneurysm, but the optimal treatment remains unclear among asymptomatic patients with an unruptured aneurysm.
Surprisingly, most of Valsalva aneurysms are congenital although some are acquired, e.g., trauma or infection. It would take several decades for a tiny pouch to glow up.