RESUMO
Currently available aortic valve prostheses have satisfactory hemodynamic performance during rest, but with exercise they possess different responses. The objective was to compare the hemodynamic response of the stentless porcine bioprosthesis (SP) and the mechanical bileaflet prosthesis (MB) at rest and during peak exercise using dobutamine stress echocardiography (DSE). DSE was used to evaluate the effective orifice area index (EOAI), peak and mean pressure gradients at rest and during maximum stress in 15 patients with SP (group T, mean age, 30.9 year) and another 15 patients with MB (group M, mean age, 28.6 year). The increment in pressure gradient (mean/peak) was significantly less in patients with SP than those with MB (P <.01). The EOAI did not change with exercise. At rest, both valve substitutes have satisfactory hemodynamics, but during exercise the stentless porcine bioprosthesis has better hemodynamics because it is less obstructive that justifies its use in young population.