Stress-related variations in left ventricular function as assessed with gated myocardial perfusion SPECT.
BACKGROUND
There is inconsistency in reported patient characteristics associated with differences in basal and poststress left ventricular function (delta ejection fraction [DeltaEF]) assessed by gated single photon emission computed tomography (SPECT). This inconsistency may therefore hamper adequate interpretation. In this study we first determined the reproducibility of serial gated SPECT-assessed left ventricular function. Second, we determined whether left ventricular ejection fraction (LVEF) assessed directly after stress reflects basal LVEF and, if not, what patient characteristics were associated with this discrepancy in LVEF.


RESULTS
Serial reproducibility of technetium 99m tetrofosmin gated SPECT-assessed LVEF in 22 patients showed a mean difference between two sequential measurements at rest of 0.09% EF units, with a 95% limit of agreement (2 SDs) at 5.8% EF units. In 229 patients Tc-99m tetrofosmin gated SPECT was performed after stress and at rest. Independent predictors of DeltaEF were the presence of scintigraphically proven ischemia (standardized coefficient, -1.256; P =.003) and difference in heart rate at the time of acquisition (standardized coefficient, 0.121; P =.001).


CONCLUSIONS
Gated SPECT-assessed LVEF at rest is reproducible under standard clinical conditions. However, LVEF assessed after stress does not represent LVEF at rest in patients with scintigraphically proven ischemia and in patients with increased heart rate after stress compared with heart rate at rest.
Verberne
Hein J
HJ
Department of Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands. h.j.verberne@amc.uva.nl
Dijkgraaf
Marcel G W
MG
Somsen
G Aernout
GA
van Eck-Smit
Berthe L F
BL
D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000209:etiology