Con: single-plane echocardiography does not provide an accurate and adequate examination of the native mitral valve.

ECHOCARDIOGRAPHY HAS become the diagnostic tool of choice for evaluating mitral valve disease, particularly by the transesophageal approach. The mitral valve is a complex structure that is affected by many disease processes. It consists of several components that make up a functional apparatus: the anterior and posterior leaflets; the anterolateral and posteromedial commissures; the annulus, including the left and right fibrous trigones, chordae tendineae that attach to both leaflets and to the 2 papillary muscles; and the anterolateral and the posteromedial papillary muscles that arise from the apical and mid portions of the left ventricular walls. Optimal interaction of the different anatomic elements is required to obtain functional integrity. Consequently, a complete and detailed assessment of the mitral valve apparatus requires optimal visualization of all of these individual elements. Appropriate diagnosis of mitral regurgitation is important because the lesion can be associated with significant morbidity and mortality.1 Repair, rather than replacement, of the mitral valve in most patients with mitral regurgitation has become the surgical procedure of choice.2-5 Left ventricular function is preserved better with mitral valve repair; prosthesis-related complications (endocarditis, thromboembolism) and lifelong anticoagulation are avoided; it is also associated with better long-term survival rates. Mitral valve repair is technically more demanding, however, and a longer procedure than a mitral valve replacement.6 There is a longer ischemic time required for visual inspection of the valve and surgical planning and testing of the repair. Direct inspection of the valve under cardioplegic arrest, with the atrium open and the valve pulled into view, may not be representative of the physiologic state.6 Transesophageal echocardiography (TEE) can present detailed information about the valve under physiologic conditions. The specific location and mechanism of regurgitation are highly correlated with anatomic and functional abnormalities so that a complete and detailed echocardiographic examination of the mitral valve before cardiopulmonary bypass (CPB) allows for the formulation of a surgical plan before ischemic arrest. The extent and location of the lesion can affect the surgical approach.7 Pre-CPB TEE examination of the mitral valve has become such an integral part of the surgical planning that even the foremost mitral valve surgeons rely on it rather than direct inspection.2 Pre-CPB TEE assessment of the mitral valve before mitral valve surgery is not in question. This discussion addresses the question whether the mitral valve can be assessed adequately and accurately using single-plane (monoplane) scanning. To answer this question, single-plane scanning must be compared with multiplane imaging to determine whether multiplane views provide more information that may affect patient outcome. The development of echocardiography began with monoplane (transverse) imaging, progressed into biplane interrogation (transverse plus longitudinal), and finally evolved into multiplane (transverse, longitudinal, and intermediate angles) imaging. Many of the comparisons available in the literature reflect the progression of the technology so that monoplane is compared with biplane and biplane with multiplane. Of interest to this discussion is that the biplane modality was embraced so enthusiastically as being a superior methodology that the expansion to multiplane was accepted almost automatically.