Table 16. Step 1: Diagnosis of severe secondary mitral regurgitation^27–32,54.

	Characteristics of severe secondary mitral regurgitation
Physical examination	Hypophonetic or normophonetic S1 Protomesosystolic or holosystolic murmur, radiating to the axillary line
Electrocardiogram	Left ventricular hypertrophy Left atrial enlargement Signs suggestive of the underlying pathology
Chest radiography	Enlarged cardiac silhouette due to dilation of left chambers
Echocardiogram	Quantification of regurgitation*: –Regurgitant fraction ≥ 50% –Regurgitant volume ≥ 60 mL/beat –EROA ≥ 0.40 cm²
Hemodynamic study	Disagreement between clinical and echocardiographic findings Degree of MR on left ventriculography
Magnetic resonance	Disagreement between clinical and echocardiographic findings or limited quality of echocardiographic image Confirmation of the degree of MR before scheduled mitral valve intervention Degree of MR

^*Consider the possibility of anatomically severe mitral regurgitation if EROA is between 0.3 and 0.4 cm ² when associated with severe systolic dysfunction. EROA: effective regurgitant orifice area; MR: mitral regurgitation.