According to a new guideline document in the September issue of the Journal of the American Society of Echocardiography, echocardiography with Doppler is now the method of choice for non-invasive evaluation of prosthetic valves.
The document, “Recommendations for Evaluation of Prosthetic Valves with Echocardiography and Doppler Ultrasound,” reviewed echocardiographic and Doppler techniques. It also provides recommendations and guidelines--endorsed by the American Heart Association (AHA), the American College of Cardiology (ACC), the European Association of Echocardiography (EAE), the Japanese Society of Echocardiography (JSE) and the Canadian Society of Echocardiography (CSE)--for evaluation of prosthetic valve function.
“Over the last 40 years, a large variety of prosthetic valves has been developed with the aim of improving blood flow function, increasing durability and reducing complications,” said lead author William A. Zoghbi, MD, of Methodist DeBakey Heart and Vascular Center in Houston. “Nevertheless, there is no ideal valve and all prosthetic valves are prone to dysfunction. The guidelines are critical to handling the evaluation of prosthetic valves and emphasize the importance of echocardiography.”
According to the authors, it remains difficult to differentiate between the “effects of prosthetic valve dysfunction from ventricular dysfunction, pulmonary hypertension, pathology of the remaining native valves or non-cardiac conditions.” Consequently, said Zoghbi, although physical examination can help determine the presence of prosthetic valve dysfunction, “diagnostic methods are often needed to assess the function of the prosthesis.”
Recommendations for assessing prosthetic valve function include obtaining pertinent clinical information, such as: date of valve replacement; type and size of the prosthetic valve; height/weight/body surface area; symptoms; blood pressure; and heart rate.
In addition, the authors recommended that the valve be imaged from multiple views, paying particular attention to:
- motion of leaflets or occluder,
- the presence of calcification on the leaflets or abnormal echo density(ies) on the various components of the prosthesis;
- and valve sewing ring integrity and motion.
The guidelines also stressed the importance of Doppler echocardiography of the valve to evalute the contour of the jet velocity signal, peak velocity and gradient, mean pressure gradient, velocity-time integral of the jet and Doppler velocity index.