Dipyridamole radionuclide ventriculography for localisation of coronary artery disease

Nineteen consecutive patients who had coronary arteriography underwent dipyridamole stress testing with 0.14 mg/kg/min infusion over 4 minutes during computer assisted radionuclide ventriculography. Global ejection fraction, diastolic function and regional ejection fraction were calculated by a semiautomatic method. There were 17 patients with severe left anterior descending disease of which 12 involved the proximal segment of the LAD, 15 patients with left circumflex disease and 13 patients with right coronary artery disease. Abnormalities in resting or stress induced regional ejection fraction was used for localisation of severe coronary artery disease. The overall sensitivity was 75 per cent with a specificity of 75 per cent, a positive predictive value of 90 per cent and a negative predictive value of 45 per cent. For LAD disease the sensitivity was 94 per cent with a 100 per cent specificity while proximal segment of LAD had a sensitivity of 100 per cent and a specificity of 57 per cent. Identification of left circumflex disease had a sensitivity of 47 per cent and a 100 per cent specificity and right coronary artery had a 85 per cent sensitivity and a 50 per cent specificity. Four patients developed ST changes, 6 developed chest discomfort and 1 patient developed giddiness. All 7 were promptly reversed with intravenous aminophylline. Thus dipyridamole radionuclide ventriculography is a highly sensitive and specific method for localisation of CAD.