Echocardiography : a Journal of Cardiovascular Ultrasound and Allied Techniques, 30, 497-504 Echocardiography. A Journal of Cardiovascular Ultrasound and Allied Techniqu, 30(5), 497-504. Wiley-Blackwell Publishing Ltd Echocardiography : a Journal of Cardiovascular Ultrasound and Allied Techniques, 30, 5, pp. 497-504