Post-stress Measurements of Left Ventricular Function With Gated Perfusion SPECT: Comparison with Resting Measurements by using Exercise and Adenosine Stress

Background and Objectives:This study examined the relationship between myocardial perfusion defects in single photon emission tomography (SPECT) and the difference in the left ventricular functional parameters obtained after stress and at rest. Materials and Method:Eighty five patients known to have or were suspected to have coronary artery disease (CAD) underwent gated Tc-99m sestamibi SPECT using a one or separate day rest/stress protocol. The post-stress left ventricular ejection fraction (LVEF-s) was compared with that at rest (LVEF-r). Myocardial stunning was blieved to have developed when the LVEF was >5% lower than that at rest. Results:Forty one (48%) patients demonstrated reversible or irreversible perfusion defects in the gated perfusion SPECT (group 1). Forty four (52%) patients demonstrated a normal perfusion status (group 2). In group 1, the LVEF-s was significantly lower than that at rest ([mean±SD] 46±15.5 vs 48±16.0 respectively, p 5% lower than the LVEF-r. Conclusion:The LVEF obtained after stress with gated SPECT may not reflect the true resting values. It is recommended that gated myocardial perfusion SPECT should be performed also at rest especially in patients with myocardial perfusion defects. (Korean Circulation J 2001;31(10):1019-1026)