Right parasternal long axis echocardiographic image of the left ventricular outflow tract showing the aortic valve in diastole. The amount of aortic valve prolapse (AVP) was measured in centimetres from a line (yellow) perpendicular to one joining the attachment of the two leaflets (red). Cineloops of this view were also used to subjectively evaluate the severity of prolapse (mild, moderate or severe). The image above was obtained from a horse deemed to have mild AVP.