Sensitivity and specificity of radionuclide ventriculography with dipyridamole infusion in patients with severe coronary artery disease

Noninvasive first-pass radionuclide ventriculography may permit the assessment of global and regional left ventricular function during dipyridamole infusion. Twenty patients with > or = 75% stenosis of at least one coronary artery were studied to assess the sensitivity of the technique in detecting coronary artery disease. Seven (35%) had regional dysfunction after dipyridamole infusion, and 16 (80%) developed lower than normal response in left ventricular ejection fraction (an increase of less than 5%) after dipyridamole infusion. When both regional dysfunction and subnormal rejection fraction were considered together, the sensitivity was 80%. Eight normal subjects were studied to assess specificity. None developed regional dysfunction, and left ventricular ejection fraction invariably increased after dipyridamole infusion in all normal subjects, with an increase of less than 5% in only one subject; therefore, the specificity was 88%. It is concluded that the assessment of regional dysfunction with dipyridamole infusion itself is not sensitive, whereas the assessment of changes in left ventricular ejection fraction is sensitive and specific in detecting coronary artery disease.