Assessment of left ventricular function in aortic stenosis.

Degenerative aortic stenosis (AS) has become the most common valvular heart disease and the definitive treatment of symptomatic, severe AS is surgical valve replacement. In the absence of symptoms, the presence of left ventricular (LV) systolic dysfunction is pivotal in making treatment decisions for patients with AS. However, the LV ejection fraction is not a sensitive marker of global LV systolic function in the presence of LV hypertrophy, implying that asymptomatic patients with AS can have myocardial dysfunction with preserved LV ejection fraction. Abnormal myocardial mechanics might explain the pathophysiological processes underlying chronic pressure overload in AS. In this article, we review how new echocardiographic deformation parameters--such as myocardial strain, strain rate, and twist measurements--offer the potential for clinicians to monitor the course of LV dysfunction in patients with AS. Quantifying disturbances in LV function might provide insight into the timing of aortic valve replacement and into the improvement of LV systolic and diastolic properties through regression of LV hypertrophy and fibrosis after valve implantation.