Basic Principles of the Echocardiographic Evaluation of Mitral Regurgitation

Mitral regurgitation (MR) is a common form of valvular heart disease that is associated with significant morbidity and mortality. Treatment decisions are completely dependent on accurate diagnosis of both mechanism and severity of MR, which can be challenging and is often done incorrectly. Transthoracic echocardiography is the most commonly used imaging test for MR; transesophageal echocardiography is often needed to better define morphology and MR severity, and is essential for guiding transcatheter therapies for MR. Multidetector computed tomography has become the standard to assess whether transcatheter valve replacement is an option because of its ability to assess valve sizing, access, and potential left ventricular outflow tract obstruction. Finally, cine cardiac magnetic resonance has been recommended by recent guidelines to quantify MR severity when the distinction between moderate and severe MR is indeterminate by echocardiography. This paper focuses on the main questions to be answered by imaging techniques and illustrates some common tips, tricks, and pitfalls in the assessment of MR.