Abnormal thallium stress test and normal coronary angiograms: Catheterization and clinical characteristics

Left ventricular end-diastolic pressure at rest, left ventricular ejection fraction, thallium segmental abnormalities, as well as sex, age and presence of diabetes mellitus, hypertension, hypercholesterolemia and smoking excess were analyzed in 40 patients with abnormal thallium stress test and normal coronary angiograms. Of these patients, 25 had elevated left ventricular end-diastolic pressure and 'low normal' ejection fraction (group 1), while the other 15 had normal left ventricular end-diastolic pressure and 'high normal' ejection fraction (group 2). The left ventricular end-diastolic pressure was 18.1 ± 4.5 mm Hg in group 1 vs. 8.5 ± 2.4 mm Hg in group 2 (P<0.000). The ejection fraction was 57.6 ± 8.3% in group 1 vs. 63.9 ± 9.1% in group 2 (P<0.05). There was no difference between the groups in relation to the abnormal segment on thallium stress tests, age and sex. Although the number of patients was too small for meaningful statistical analysis, most of the patients with diabetes mellitus, hypertension, hypercholesterolemia or smoking history were in group 1. Thus, the patient population with abnormal results on radionuclide exercise tests and angiographically normal coronary arteries probably comprises two groups: a) patients with decreased diastolic and relatively decreased systolic performances which might reflect coronary flow disturbances, and b) patients with normal diastolic and systolic performances, probably reflecting 'true false positive thallium stress test'.