• mitral regurgitation
• transoesophageal echocardiography
• transthoracic echocardiography

• EROA, effective regurgitant orifice area
• FC, flow convergence
• LVOT, left ventricular outflow tract
• MR, mitral regurgitation
• TOE, transoesophageal echocardiography
• TTE, transthoracic echocardiography
• VC, vena contracta
• VTI, velocity time integral

Mitral regurgitation (MR) is the most commonly encountered valve lesion in modern clinical practice.¹ The range of pathologies producing regurgitant mitral valve dysfunction is broad (table 1) and the condition may be met in virtually any medical speciality. As echocardiography is the most widely available cardiac imaging modality, it is the technique which is routinely used to assess patients with suspected or known MR. While echo-Doppler is an excellent technique for detecting the presence of MR and defining the underlying pathological cause, assessing and/or quantifying the severity of the leak by echocardiography can at times be difficult. This reflects the fact that regurgitant flow through the mitral valve is a complex and dynamically changing process which may be impossible to characterise fully using a two dimensional imaging modality. Nevertheless, if MR is discovered on an echocardiographic examination it is extremely important to make an assessment of severity as this will be required to guide the patient’s subsequent management.

What therefore is the optimal way to assess the severity of MR? Do potentially cumbersome quantitative echo-Doppler methods for calculation of regurgitant orifice area, regurgitant volume or regurgitant fraction add anything to a subjective assessment of severity (mild, moderate, severe) carried out by an experienced sonographer? Should already busy and overburdened echocardiography staff be stretching themselves further to perform complex quantitative techniques on MR patients? The answer is probably that detailed quantification is not necessary in the majority of patients. Non-cardiologists need to know whether the regurgitation is significant enough to warrant further cardiological assessment; this does not require detailed quantitative information. Cardiologists use echo-Doppler grading of regurgitation severity in conjunction with patient symptoms and signs and occasionally invasive haemodynamic information to make decisions on the need for and timing of mitral valve surgery. In the majority …