Estimation of Left Ventricular Volume by One-Plane Cineangiography

One-plane cineangiographic measurement of left ventricular volume uses angiocardiograms taken in the right anterior oblique view. Its basic assumption is that the third (unvisualized) dimension, depth from septum to free wall, is of the same magnitude and behaves in the same way as the visualized short axis. Examination of this assumption with biplane x-ray equipment revealed that the unmeasured length averages 7% less and varies directly with the length of the measured short axis. Volumes measured correlate well with consecutive studies using serial biplane x-rays and are systematically somewhat larger than volumes obtained in autopsy specimens injected with barium sulfate paste. The method is tolerant of variations in positioning of the patient, is convenient, yields repeatable analyses from one experienced observer to another, allows 60 volume measurements per second so that rapid cardiac events can be studied, and the small doses of x-rays and contrast medium permit several observations at one catheterization session. This means that effects of drugs and other interventions can be studied by the informative techniques of semi-continuous volume measurement and pressure-volume analysis.