The Echocardiographic Evaluation of a Bicuspid Aortic Valve: The Effect of Jet Eccentricity and Left Ventricular Outflow Tract Geometry on the Effective Orifice Area

Abstract

A 29-YEAR-OLD MALE (180 cm, 65.8 kg) with a bicuspid aortic valve presented for an aortic valve replacement (AVR). Preoperative two-dimensional (2D) transthoracic echocardiography (TTE) demonstrated preserved left ventricular function along with a resting maximum aortic valve (AV) velocity of 4.33 m/s and mean pressure gradient of 41 mmHg. This increased to a maximum AV velocity of 5.56 m/s and mean gradient of 65 mmHg when stressed with dobutamine. Using the continuity equation (CE), effective orifice area (EOA) of the AV was calculated to be 0.9 cm2 (0.52 cm2/m2) given a left ventricular outflow tract (LVOT) diameter of 2.3 cm, velocity time integral of the LVOT (VTIlvot) of 23.6 cm and velocity time integral of aortic valve (VTIav) of 107 cm (Fig 1).