[Clinical significance of aortic ring dilatation and changes in aortic root configuration in the pathogenesis of non-rheumatic aortic regurgitation].

This study was undertaken to determine the etiology of non-rheumatic aortic regurgitation (AR) by two-dimensional echocardiography. Dimensions of the aortic root at the levels of the surgical aortic ring (ARDs), sinus of Valsalva (AOD), and anatomical aortic ring (ARD) were measured in 23 patients who underwent aortic valve replacement due to AR with idiopathic aortic root dilatation, in 15 hypertensive patients without AR and in 15 normal controls. The 23 patients with AR were classified as annuloaortic ectasia (AAE) (seven cases) and non-AAE (16 cases) groups. In the AAE group, the ascending aorta and aortic root were markedly dilated and had a pear-like configuration on aortography while the aorta had a normal configuration in the non-AAE group. ARDs was significantly larger in the non-AAE and AAE groups than in the hypertension and normal control groups. AOD and ARD were significantly larger in the hypertension and non-AAE groups than in the normal controls, and those in the AAE group were greater than those in any other group. The end-diastolic shape of the aortic valve in the long-axis view was "Y" shaped in the normal control and hypertension groups, "T" shaped in the non-AAE group, and the patients with AAE showed no cuspal coaptation. AR due to aortic ring dilatation, mainly reported by pathologists, were due to marked degree of ARD dilatation. However, our two-dimensional echocardiographic study showed that moderate dilatation of the entire aortic root in the non-AAE group seemed to be an important factor in the genesis of AR, even without dilatation of ARD.