A comparison of right ventricular volume change during systole obtained using the monoplane Simpson's method in two-dimensional echocardiographic apical four-chamber view with right ventricular volume change obtained using a prisma model reflecting the systolic long-axis shortening of the right ventricle of the heart: A pilot study.

The right ventricle of the heart has a complex geometry, making it difficult to measure its function and volume. In the present study, right ventricular (RV) volume change during systole in two-dimensional echocardiographic apical four-chamber view was estimated using the monoplane Simpson's method. Measurements of volume change using the monoplane Simpson's method were compared with those obtained using a theoretical prisma model, which is believed to reflect RV systolic long-axis shortening. The mean volume change during systole obtained using the theoretical prisma model (10.2+/-3.2 mL) was significantly (P<0.001) smaller than that obtained using the monoplane Simpson's method (20.7+/-7.1 mL). This difference was probably due to the patient group studied, which had a mean (+/- SD) age of 58.6+/-14.1 years. In elderly individuals, systolic shortening in the short-axis direction has a greater impact on volume change during the heart cycle more than in younger individuals. However, not even the volume change during systole obtained using the monoplane Simpson's method in echocardiographic four-chamber view was able to determine the 'real' RV stroke volume. Thus, the volume change during systole in other echocardiographic views needs to be considered as well.