Aortic Stenosis

The key to defining the diagnosis of aortic stenosis in our patient was the recognition of the classic systolic crescendo-decrescendo murmur.

We have also defined the severity by the company it keeps, including the non-auscultatory elements of the bedside examination and additional auscultatory findings. The latter include the long length of the murmur and the fourth heart sound. The congenital etiology was defined by the presence of an ejection sound. The ejection sound also indicates that the obstruction is at the level of the aortic valve and that the aortic valve is mobile.

Aortic outflow tract obstruction may be supravalvular, valvular, or subvalvular. The latter is most often muscular and is seen in association with hypertrophic cardiomyopathy. Significant isolated valvular aortic stenosis in the younger patient is most often due to a congenitally bicuspid valve. During middle age, a less significantly stenosed bicuspid valve may also undergo fibrosis and calcification with commissural fusion that results in significant obstruction. In the elderly patient, significant aortic stenosis most often occurs when a normal 3-cusped valve undergoes degeneration associated with fibrosis and calcification.

Aortic stenosis in the elderly may present a difficult bedside diagnosis. This includes findings in the arterial pulse, precordial movement and on auscultation. The arterial pulse pressure may be wide and the carotid impulse normal due to arteriosclerosis. Precordial movement may be masked due to an increase in the antero-posterior diameter of the chest. If abnormal impulses are present, they could be due to concomitant coronary artery disease.

On auscultation, the upper right sternal edge murmur may be unimpressive due to chest configuration and the presence of heart failure, causing markedly decreased stroke volumes. An apical fourth sound is common in this age group, and an apical systolic murmur may be heard due to a calcified mitral annulus and/or papillary muscle dysfunction. When the aortic valve becomes calcified and immobile, an ejection sound and the aortic component of the second heart sound are often absent.

In some elderly patients, a systolic aortic murmur may be heard. It originates across a sclerotic aortic valve. The murmur occurs in early systole when the majority of blood is normally ejected from the ventricle and reflects turbulent flow without significant left ventricular outflow obstruction. It used to be referred to as the "innocent murmur of the elderly." In some cases, the lesion may progress, with fibrosis and calcification leading to commissural fusion and valve stenosis.