ASSESSMENT OF LEFT-VENTRICULAR DIASTOLIC FUNCTION - COMPARISON OF CONTRAST VENTRICULOGRAPHY AND EQUILIBRIUM RADIONUCLIDE ANGIOGRAPHY

Twenty-two patients with coronary artery disease were studied first by radionuclide angiography (RNA) and then by contrast ventriculography. Cardiac medications were discontinued at least 72 hr before study. The patients were studied during atrial pacing at heart rates close to their spontaneous sinus rhythm. Contrast ventriculography was performed at 50 frames/sec in the 30-degrees right anterior oblique projection using 40 ml of a nonionic contrast medium (iopamidol) at a flow rate of 10-12 ml/sec. The contours of the left ventricular silhouette at contrast ventriculography were traced, frame by frame, on a graphic table with a digitizing penlight. Equilibrium Tc-99m RNA was performed in the best septal 45-degrees left anterior oblique projection, acquiring 150,000 cts/frame, at 50 frames/sec and with a 5% gate tolerance. Time-activity curves from both end-diastolic and end-systolic ROIs were built and interpolated. Both RNA and contrast ventriculography volume curves were filtered with Fourier five harmonics. A close relationship was found between RNA and contrast ventriculography measurements of peak filling rate normalized to end-diastolic cps (r = 0.87, p < 0.001) and stroke count (r = 0.87, p < 0.001), ejection fraction (r = 0.94, p < 0.001). Thus, in patients with coronary artery disease, LV filling can be accurately assessed using RNA.