Background:
This study determines the value of gated single photon emission computed tomography (spect) imaging soon after exercise to identify patients with single-vessel disease and exercise-induced prolonged myocardial dysfunction (ie, postischemic stunning).
Methods and results:
We examined 19 normal individuals and 52 patients with single-vessel disease by use of 2-day technetium 99m tetrofosmin exercise/rest gated spect imaging. sequential imaging was started 10, 30, and 50 minutes after exercise. the ejection fraction (ef) values were calculated with the cedars-sinai program. the participants were classified as follows: group a (normal individuals, n = 19), group b (individuals with coronary stenosis without q-wave infarction, n = 18), group c (individuals with q-wave infarction without myocardial ischemia, n = 15), and group d (individuals with q-wave infarction and ischemia, n = 19). the post-stress ef values at 10 minutes (69.8% +/- 9.6% and 59.8% +/- 11.8%, respectively) were higher in groups a and c than those at 30 minutes (67.6% +/- 10.2% and 57.2% +/- 11.3%, respectively) ( p < .05) but were lower in group b (61.7% +/- 9.2%) than both the 30- and 50-minute values (64.2% +/- 9.5% and 64.6% +/- 9.4%, respectively; p < .05). the ef value did not significantly change in group d.
Conclusions:
Tc-99m gated spect imaging soon after exercise is superior to conventional late imaging to discriminate patients with single-vessel disease and postexercise stunning.