|Grade||Definition||Valve Anatomy||Valve Hemodynamics∗||Associated Cardiac Findings||Symptoms|
|A||At risk of MR|
|C||Asymptomatic severe MR|
|D||Symptomatic severe MR|
2D indicates 2-dimensional; ERO, effective regurgitant orifice; HF, heart failure; LA, left atrium; LV, left ventricular; MR, mitral regurgitation; and TTE, transthoracic echocardiogram.
↵∗ Several valve hemodynamic criteria are provided for assessment of MR severity, but not all criteria for each category will be present in each patient. Categorization of MR severity as mild, moderate, or severe depends on data quality and integration of these parameters in conjunction with other clinical evidence.
↵† The measurement of the proximal isovelocity surface area by 2D TTE in patients with secondary MR underestimates the true ERO because of the crescentic shape of the proximal convergence.