Effects of changing blood viscosity and heart rate on vena contracta width as evaluated by color doppler flow mapping: an in vitro study with a pulsatile flow model - Schmidt, André; Silva Júnior, Telêmaco da; Pazin-Filho, Antônio; Murta Júnior, Luiz Otávio; Almeida-Filho, Oswaldo César; Gallo Júnior, Lourenço; Marin-Neto, José Antônio; Maciel, Benedito Carlos (Echocardiography, 2008)