Left ventricular function and myocardial perfusion during dipyridamole infusion assessed by a single injection of 99Tcm-sestamibi in patients unable to exercise.

First-pass radionuclide ventriculography followed by myocardial single photon emission computed tomography (SPECT) with 99Tcm-methoxyisobutyl isonitrile (sestamibi) was performed at rest and during dipyridamole infusion in 42 patients with suspected coronary artery disease. The presence of coronary stenoses of > or = 50% diameter was compared with the presence of rest or dipyridamole-induced abnormalities in perfusion or left ventricular function. Radionuclide-determined left ventricular ejection fraction (LVEF) was highly reproducible and correlated well with LVEF derived from contrast left ventriculography. Left ventricular ejection fraction decreased significantly after dipyridamole infusion in patients with multivessel disease (58 +/- 10% versus 52 +/- 11%, P < 0.01). The sensitivity and specificity for the detection of patients with coronary artery disease were 85 and 75% by myocardial SPECT, and 47 (P < 0.01 versus SPECT) and 75% by LVEF, respectively. However, in patients with multivessel disease, the sensitivity of LVEF was not different from that of SPECT (72% versus 89%, P = ns). The sensitivity of LVEF was higher in patients with multivessel disease than in those with single-vessel disease (19% versus 72%, P < 0.01). Radionuclide ventriculography followed by myocardial SPECT with 99Tcm-sestamibi allows simultaneous evaluation of ventricular contractile function associated with perfusion abnormality during dipyridamole infusion and may enhance the functional description of myocardial ischaemia.