Một máy bay phản lực dễ dàng nhìn thấy là thường paraprosthetic, kể từ khi trào ngược transprosthetic bình thường có xu hướng được ẩn bởi dòng chảy che chắn (trừ khi LA là rất lớn). Khu vực dòng chảy trong não thất tuyển dụng của một máy bay phản lực regurgitant paraprosthetic thường có thể được nhìn thấy ngay cả khi các máy bay phản lực trong tâm nhĩ là vô hình. | 7o Echocardiography A Practical Guide for Reporting Table When to suspect aortic obstruction Thickened or immobile cusps or occluder Measurements outside normal values see Appendix 2 Change in measurements by about 25 on serial studies TOE is occasionally necessary to confirm normal leaflet motion in a valve with an equivocal EOA. MITRAL POSITION 1. Is there regurgitation An easily seen jet is usually paraprosthetic since normal transpros-thetic regurgitation tends to be hidden by flow shielding unless the LA is very large . The intraventricular flow recruitment region of a paraprosthetic regurgitant jet can usually be seen even when the intra-atrial jet is invisible. This allows the regurgitation to be localised using the sewing-ring as a clockface. 2. Severity of mitral prosthetic regurgitation Severe paraprosthetic regurgitation may be obvious from - a large region of flow acceleration within the LV - a broad neck - a hyperdynamic LV - a dense continuous-wave signal especially with early depressurisation dagger shape . If there is doubt TOE is necessary to evaluate jet width the size of the intra-atrial jet and PV flow looking for systolic flow reversal . 3. Is there evidence of obstruction Table Most information for the diagnosis of obstruction is found from imaging and colour flow mapping. Measure Vmax and mean gradient and compare with normal values Appendix 2 . Pressure half-time does not reflect orifice area in normally functioning prosthetic mitral valves so the Hatle orifice area formula is not Prosthetic valves 7I Figure Normal transprosthetic regurgitation. a A thin jet of regurgitation through a homograft aortic valve imaged in a parasternal long-axis view. b A tilting-disk aortic valve imaged in an apical long-axis view showing regurgitation related to the major and minor orifices. c A bileaflet mechanical aortic valve in a parasternal shortaxis view showing two jets from the upper and two from the lower pivotal point Echocardiography A .
