The sinus of Valsalva is a structure that connects the aortic annulus and the aortic wall. Aortic cusps join with the aortic wall at the sinotubular junction. The aortic sinuses (sinuses of Valsalva) are dilated pockets of the aortic root located between the sinotubular junction and the aortic annulus. The walls of the sinuses are considerably thinner, or in some cases their supporting muscular tissues are underdeveloped, with the result that the walls of the sinuses are inclined to dilation and forming of aneurysms under the pressure of blood flow. The dilation and aneurysm is termed sinus of Valsalva aneurysm. The wall of the aneurysm continuously becomes thinner under blood pressure and may eventually rupture if factors such as infection and displacement are involved, which is seen most commonly in the right coronary sinus (Fig. 22.1a–d).

With the rupture of the sinus of Valsalva aneurysm, blood drains from the aorta into adjacent heart chambers, leading to hemodynamic disorders. Different rupture locations result in different drainages of the heart chamber (Figs. 22.2 and 22.3). Unruptured aneurysms usually are asymptomatic, unless they block the outflow portion of the RV or fall into the LV, causing aortic insufficiency. A large amount of left-to-right blood flow or severe aortic insufficiency inevitably leads to pulmonary hypertension and heart failure.

Several different classifications of sinus of Valsalva aneurysm, based on clinical practices, have been accepted and applied: