Supine thallium 201 cardiac testing compared with treadmill testing.

Although thallium 201 stress testing is usually performed on a treadmill (Tl-TM), supine bicycle-ergometer-exercise thallium 201 testing (Tl-SB) has been reported. We performed a study to evaluate the accuracy of Tl-SB in evaluation of coronary artery disease and to correlate its results with those of Tl-TM. Fifty patients underwent both Tl-SB and Tl-TM testing in random sequence an average of 1 week apart. Tl-TM produced significantly higher maximal pulse rates and pulse-pressure products. Cardiac thallium kinetics differed significantly between Tl-SB and Tl-TM with Tl-TM producing greater initial myocardial uptake and greater thallium 201 washout between immediate and delayed images. Compared with results of catheterization, Tl-TM was significantly more accurate than Tl-SB for evaluation of coronary artery disease, with higher sensitivity and specificity.