Simultaneous perfusion tomography and radionuclide angiography during dobutamine stress

The purpose of this investigation was to evaluate the changes in left ventricular function and volumes concurrently with tomographic myocardial perfusion during dobutamine infusion. Methods: Ninety-two patients underwent first-pass radionuclide angiography using a multicrystal gamma camera and myocardial tomography after high-dose (40 μg/kg/min) dobutamine infusion and ^99mTc-sestamibi administration. Results: Dobutamine increased systolic blood pressure (p < 0.0001), heart rate (p < 0.00017), left ventricular ejection fraction (p = 0.0001), cardiac output (p = 0.0001) and stroke volume (p = 0.042). The end-diastolic (p = 0.009) and end-systolic volumes (p = 0.0007) significantly decreased. Of 38 patients with cardiac catheterization, 28 had significant coronary artery disease and 10 had normal coronaries. The sensitivity and specificity for coronary artery disease detection by myocardial perfusion tomography were 78% and 90%, respectively. By radionuclide angiography, only 9 of 27 coronary artery disease patients experienced deterioration of wall motion during dobutamine (sensitivity 33%). Conclusion: Changes in myocardial perfusion are more sensitive than changes in left ventricular function for detecting coronary artery disease during dobutamine stress.