[Determination of right ventricular volume by subxiphoid two-dimensional echocardiography (author's transl)]

To establish the measurement method of right ventricular (RV) volume by two-dimensional (2-D) echocardiography, a comparative study was performed in respect to the quantitative evaluations of the RV areas or volumes obtained by biplane 2-D echographic and angiographic methods. At first, a preliminary investigation was performed to define the optimum tracing of the endocardial surface on the 2-D echogram by using a fresh mongrel dog heart. It was revealed that the 2-D echographic views of the ventricular surface contained some artifact echoes inside the true echo of the endocardium. As a result, the optimum line for tracing was considered to be in external margin of the echo which seemed to represent the endocardium. This technique was then applied to 10 patients with congenital heart disease who were followed by cardiac catheterization. Ages ranged from 9 months to 5 years with an average of 2 years and 4 months. The RV was imaged by a subxiphoid approach. The RV apex, pulmonary valve (PV) and mid-portion of the tricuspid valve were showed in a frontal view, which allowed to measure the frontal RV area (f). In a sagittal plane, the RV wall and the PV were imaged, and then the lateral area (l) and the RV long axis (d) were measured. From the biplane cineangiography, the frontal RV area (f') lateral area (l'), RV long axis (d') and RV end-diastolic volume (EDV) by arealength method were calculated. The f and l were correlated with the f' (r = 0.90) and with the l' (r = 0.86), respectively. However, the values by the echocardiographic measurement were smaller than those by the cineangiographic ones. The f was also well correlated with the RVEDV (r = 0.94). The f.l/d, considered to represent a variable of echography measurement of the RV volume by area-length method, was well correlated with the RVEDV (r = 0.84). Although there are still some problems related to the imaging technique and sharpness of the echogram, further improvement to establish a echocardiographic measurement of RV volume is expected with the advance of the techniques.