Real-time three-dimensional transthoracic echocardiography.

BACKGROUND Complex anatomy of intra-cardiac structures requires spatial orientation of image in three dimensions for better understanding and enhanced image interpretation. We evaluated the feasibility and efficacy of the emerging 'real-time three-dimensional transthoracic echocardiography' technique for comprehensive assessment of cardiac anatomy, physiology, pathomorphology and pathophysiology in patients with structural heart disease. METHODS AND RESULTS Patients with structural heart disease (n=152) were evaluated by conventional two-dimensional transthoracic echocardiography and real-time three-dimensional transthoracic echocardiography using standard protocol. Fifty-six cases were of rheumatic etiology with multi-valvular involvement (mitral stenosis: 32; mitral regurgitation: 29; tricuspid regurgitation: 8; aortic valve disease: 11) and 21 cases of non-rheumatic valvular heart disease. A total of 38 congenital heart disease patients were examined including 23 patients with atrial septal defect. Left ventricular function (n=20) and right ventricular function (n=10) were also assessed using dedicated software. CONCLUSIONS Results of real-time three-dimensional transthoracic echocardiography mitral valve area assessment by planimetery are comparable to two-dimensional transthoracic echocardiography with additional information about surface anatomy of leaflets and the subvalvular apparatus in real time with clear demarcation of commissural fusion and scallops of leaflets. Enface view of atrial septal defect with direct visualization of shape, size and number of defects, tricuspid valve area by planimetery, right ventricular shape, objective assessment of ventricular volumes and regurgitation vena contracta area are the fields where three-dimensional transthoracic echocardiography was of additive value to conventional two-dimensional transthoracic echcardiography. This study proves clinical feasibility of real-time three-dimensional transthoracic echocardiography but requires further validation of quantitative observations.