Postextrasystolic potentiation in low-gradient, severe aortic stenosis: a poor man's stress echo?

An elderly man with dyspnea and syncope was found to have severe aortic stenosis (AS) by the continuity equation, despite a transaortic gradient that was only moderately elevated, in the setting of severe left ventricular dysfunction. The transaortic gradient increased during postextrasystolic beats, suggesting that his that his AS was truly severe; this was confirmed by dobutamine echocardiography. He underwent transcatheter aortic-valve replacement (TAVR), with subsequent improvement in left ventricular systolic function. The diagnostic and prognostic significance of postextrasystolic potentiation, with associated increase in aortic stenosis gradient, deserves renewed attention in the TAVR era.