The feasibility of epicardial echocardiography for measuring aortic valve area by the continuity equation.
Hilberath JN, Shernan SK, Segal S, Smith B, Eltzschig HK. The feasibility of epicardial echocardiography for measuring aortic valve area by the continuity equation. Anesth Analg. 2009 Jan; 108(1):17-22.