Functional limitation in aortic valve disease: superiority of bicycle test to symptom-rated appraisal?

The overall functional capacity in aortic valve disease was evaluated using the New York Heart Association criteria and symptom-limited bicycle ergometry in 80 patients who underwent cardiac catheterization. The correlations between exercise performance and resting cardiac haemodynamics and clinical class were poor. Similar exercise tolerance appeared to be associated with comparable resting left ventricular (LV) performance in each haemodynamic subgroup. Limitation in exercise tolerance in aortic stenosis (n = 25), as defined by peak work-load achieved and work-pulse index, together with an inability to raise systolic blood pressure during exercise, appeared to be associated not only with a more significant reduction in LV systolic pump function and compliance but also with greater LV dilatation. A lack of correlation between exercise performance and resting LV function was seen in patients with aortic regurgitation (n = 35); and, to large extent, in those with combined lesion (n = 20). The severity of the valvular lesion was not indicated by functional limitation in any of the subgroups, although greater systolic blood pressure during exercise appeared to reflect more significant valvular leakage in the combined lesion group. It is concluded that objective tests of exercise tolerance are to be preferred in monitoring the course of the disease and the therapy provided. Aortic regurgitation appears to cause as great a limitation in exercise tolerance as does aortic stenosis alone, but may not be associated with greater deterioration in LV function at a similar level of functional limitation. Pressure overload to the LV may explain the ability of impaired LV function to reflect the limitation in exercise tolerance in cases of aortic stenosis.