Estimation of left ventricular volumes in man from biplane cineangiograms filmed in oblique projections

Abstract

In patients with coronary artery disease, right and left anterior oblique views of the left ventricle are considered optimal for assessment of regional wall motion, but the accuracy of ventricular volumes determined from these projections has not been validated. Eleven postmortem left ventricular casts were filmed with the 35 mm cine technique in the 30 ° right anterior oblique and 60 ° left anterior oblique positions, and volumes were calculated using the area-length method. True volume, assessed from volume displacement, ranged from 15 to 185 cc. Calculated volume (V oblique) slightly but consistently overestimated true volume (V T), with close correlation and a small standard error of the estimate (SEE):V T = 0.989 V oblique − 8.1 cc, r = 0.99, SEE = 8 cc. With use of this regression equation, values for left ventricular volumes and ejection fraction were calculated from biplane oblique (30 ° right anterior oblique/60 ° left anterior oblique) cineanglograms In 17 normal adults. Values for end-diastolic volume index (72 ± 15 cc/m 2 [mean ± standard deviation]), end-systolic volume index (20 ± 8 cc/m 2), stroke volume Index (51 ± 10 cc/m 2) and ejection fraction (0.72 ± 0.08) were similar to those reported by others. Examination of the effects of variable obliquity suggests that strict standardization of the degree of obliquity is necessary to offset variation In the long axis in the left anterior oblique projection caused by foreshortening.