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 cm(2)), 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.