Use of first-pass radionuclide ventriculography in assessment of wall motion abnormalities induced by incremental atrial pacing in patients with coronary artery disease.

In order to show that stress-induced changes in ventricular function can be determined by radionuclide techniques, 13 patients with coronary artery disease were paced to angina. Changes in ejection fraction and regional wall motion were measured from contrast angiograms and first-pass nuclear angiograms performed using a multicrystal gamma camera. A count-volume method applied to the nuclear technique demonstrated a significant fall in ejection fraction on pacing. The area-length method was also applied to both techniques and a significant fall in ejection fraction was induced by pacing in both contrast and nuclear angiograms. There was a good correlation between ejection fraction on pacing derived from contrast and count-volume nuclear angiograms. Those patients with greater falls in ejection fraction were identified by both techniques. Changes in regional wall motion were assessed by a hemiaxial method. All six anterior and all four inferior pacing-induced zones of hypokinesis identified on contrast angiography were demonstrated by the nuclear technique. Of three apical regions of pacing-induced hypokinesis seen on contrast angiography one was shown by the nuclear method. All 11 zones of pacing-induced hypokinesis seen on nuclear angiography were in regions supplied by significantly stenosed coronary vessels.