19 - Prosthetic valves

Summary

There are comprehensive international guidelines for the echocardiographic assessment of prosthetic valves and the management of clinical problems. The minimum dataset is peak velocity, mean pressure difference, and effective orifice area (EOA). It is important to derive the mean pressure difference, because it is calculated using the whole wave-form and reflects function better than using the peak velocity alone. Errors arise if the peak velocity is used in place of the velocity integral. Paraprosthetic regurgitation is differentiated from transprosthetic regurgitation by the jet having its origin outside the sewing ring. The tricuspid valve is imaged from the bicaval view obtained in the low esophageal four-chamber view, with further 90° rotation and the probe turned counterclockwise. Quantitative Doppler should always be interpreted in the clinical context; normal ranges vary with design, position, and size. Tranthoracic and transesophageal echocardiography are complementary and should not be considered in isolation.