Echocardiographic assessment of ventricular dyssynchrony.

Although cardiac resynchronization therapy (CRT) has been of unquestioned therapeutic benefit to many patients with heart failure identified by a widened QRS complex on an electrocardiogram, many patients do not respond favorably. Several studies using echocardiographic methods to measure abnormalities of mechanical activation, known as dyssynchrony, have been proposed to improve patient selection for CRT. Many single-center studies from institutions with special expertise have demonstrated the feasibility of echocardiographic dyssynchrony to potentially assist with patient selection. However, the PROSPECT trial, a recent large multicenter study, highlighted the technical challenges in echocardiographic dyssynchrony analysis in mainstream clinical practice. Accordingly, a uniform clinical approach has not been established, and refinements of echocardiographic approaches and methods are constantly evolving. This article reviews current echocardiographic methods to quantify ventricular dyssynchrony, their strengths and limitations, and the proposed and potential expanding clinical applications.