Exercise Cardiac Catheterization for Hemodynamic Evaluation of Paradoxical Low-Flow Low-Gradient Severe Aortic Stenosis.

Patients with paradoxical low-flow low-gradient aortic stenosis pose a diagnostic challenge when it comes to assessing the severity of aortic stenosis (AS) noninvasively. We describe 2 patients who underwent exercise cardiac catheterization to augment their cardiac output and assess the severity of AS invasively to allow differentiation of true severe AS from pseudo-severe AS.