Gated ADSPECT performed early after AMI can accurately identify a sizeable low-risk group who have a <2% death and reinfarction rate at 1 year. Identifying these low-risk patients for early hospital discharge may improve utilization of health care resources at considerable cost savings.

Background-Alterations in adrenergic receptor densities can potentially contribute to myocardial dysfunction. Their relevance to myocardial hibernation in humans is unknown. Methods and Results-Accordingly, 22 transmural myocardial biopsies were obtained in 11 patients with ischemic ventricular dysfunction during bypass surgery, guided by transesophageal echocardiography. Patients underwent dobutamine echocardiography (DE) and rest scintigraphic studies before revascularization and DE at 3 to 4 months. ␣-and ␤-receptor density (ARD and BRD) and extent of fibrosis were quantified from the myocardial biopsies. Of the 22 segments, 16 had abnormal rest function and 6 were normal. Severely hypokinetic or akinetic segments showed a 2.4-fold increase in ARD with a concomitant 50% decrease in BRD compared with normal segments. An increase in ARD, a decrease in BRD to a lesser extent, and thus an increase in ARD/BRD ratio were seen in dysfunctional segments with contractile reserve compared with normal segments and were most pronounced in those without contractile reserve (PϽ0.001). Similar findings were observed if recovery of function or scintigraphic uptake was analyzed as a marker for viability. No significant relation between either ARD or BRD and percent myocardial fibrosis was noted (rϭ0.37 and Ϫ0.39, respectively). Conclusions-Thus, graded and reciprocal changes in ␣-and ␤-adrenergic receptor densities occur in viable, hibernating myocardium and may account in part for the observed depression in resting myocardial function and preserved contractile reserve in this entity.

Risk reclassification by diagnostic testing is importantly influenced by baseline characteristics of patient cohorts. In patients with suspected CAD, NRI is predominately achieved by exercise variables, whereas in patients with known CAD, greatest NRI is obtained by MPI variables.

TESA is an effective technique for relieving left ventricular outflow obstruction in patients with HOCM. Myocardial gated SPECT can identify the presence and location of infarction after TESA.

This study is about an elderly female patient who presented with rapid atrial fibrillation. Pharmacologic stress myocardial perfusion imaging with dipyridamole for the assessment of myocardial ischemia resulted in transient abnormalities on electrocardiogram, wall motion and perfusion defects with complete resolution 1 month later, suggestive of Takotsubo cardiomyopathy. We believe that our case report is the first to describe this finding after dipyridamole stress.