When is an aortic valve prosthesis too small? The need for dobutamine stress echocardiography

We describe a patient who had undergone aortic valve replacement with a small prosthesis 10 years previously and who presented with exertional breathlessness. The resting transaortic pressure gradient was only 30 mmHg but increased to 165 mmHg on dobutamine stress. Conventional resting echocardiography may fail to demonstrate abnormal prosthetic aortic valve function; in the presence of symptoms, dobutamine stress echocardiography should be considered.