DOBUTAMINE STRESS RADIONUCLIDE VENTRICULOGRAPHY FOR THE DETECTION OF CORONARY-ARTERY DISEASE

Thirty patients were prospectively studied to assess the value of radi onuclide ventriculography (RNV) during step-wise dobutamine infusion f or the detection of coronary artery disease (CAD). Radionuclide ventri culography was performed under basal conditions and during dobutamine infusion at each 10 mug kg-1 min-1 dose increment from 10 to a maximum of 40 mug kg-1 min-1. The test response was considered positive if th e ejection fraction (EF) decreased by more than 5% or if segmental con traction abnormalities developed. Dobutamine stress testing was well t olerated, no complications and no significant arrhythmia were observed . In nine of 11 patients without CAD, EF increased more than 5% of the rest value and the left ventricular wall motion was normal in 10 of t hem during dobutamine infusion (specificity 91%). In 18 of 19 patients with CAD, new wall motion abnormalities (WMA) were identified in segm ents corresponding to the arterial lesions diagnosed by angiography (s ensitivity 94%). Ejection fraction response was significantly differen t in normal subjects and in patients with CAD: 11 +/- 5.9% versus 1.9 +/- 9.5% (P < 0.01). However, abnormal EF response was found in seven of 19 CAD patients and development of new WMA was found to be a more s ensitive and specific parameter than EF response for dobutamine RNV. I t is concluded that dobutamine RNV is an accurate, widely available an d cost-effective test for detecting CAD, especially in patients unable to exercise.