Low‐level Exercise Echocardiography Fails to Elicit Left Ventricular Contractile Reserve in Patients with Aortic Stenosis, Reduced Ejection Fraction, and Low Transvalvular Gradient

Background: Low-level exercise echocardiography is useful to assess left ventricular (LV) contractile reserve after an acute myocardial infarction. Whether low-level exercise can elicit LV contractile reserve in patients with severe aortic stenosis, reduced LV systolic function and low transvalvular gradient are unknown. Accordingly, the value of low-level exercise to elicit contractile reserve was assessed in these patients using dobutamine administration as the gold standard method. Methods and Results: Seventeen patients with severely decreased aortic valve area (0.75 ± 0.03 cm2), reduced LV ejection fraction (35 ± 2%) and low mean transvalvular gradient (23 ± 3 mmHg) underwent low-level exercise and dobutamine echocardiography. Ejection fraction increased by 23% (P < 0.001) with dobutamine and decreased by 8% (P = 0.2) with low-level exercise. Left ventricular outflow tract velocity time integral increased from 13 ± 1 to 16.7 ± 1 cm (P < 0.001) with dobutamine but did not change with low-level exercise (13 ± 1 vs. 13.5 ± 1, P = 0.5). Conclusion: Low-level exercise fails to elicit LV contractile reserve in patients with severe aortic stenosis, reduced LV systolic function, and low transvalvular gradient.