Assessment of mitral regurgitation

Abstract

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 sus- pected 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 proc- ess which may be impossible to characterise fully using a two dimensional imaging modality. Nevertheless, if MR is discov- ered 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 them- selves further to perform complex quantitative techniques on MR patients? The answer is probably that detailed quantifica- tion is not necessary in the majority of patients. Non- cardiologists need to know whether the regurgitation is significant enough to warrant further cardiological assess- ment; 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 of cases, quantitative echo-Doppler data are not required for this purpose and in fact current American College of Cardiology/American Heart Association guidelines for the management of MR 2 do not make reference to any formal quantitative information. From time to time, however, situations will be encountered where there is discrepancy between the echocardiographic grading of regurgitation and the findings on clinical examination or other imaging modali- ties. In these circumstances more detailed quantitative echo-Doppler data may be required and it is important that the echocardiographer is conversant with the techniques involved.In addition,valve repair is increasingly performed on asymptomatic MR patients, and it may be that quantitative data such as regurgitant orifice area will become useful in the serial follow up of this group and in the decision of timing of surgery.