title: Stress-induced abnormalities in myocardial perfusion imaging that are not related to perfusion but are of diagnostic and prognostic importance.
abstract: BACKGROUND
  Certain stress-induced ancillary findings on myocardial perfusion scintigraphy increase the likelihood that the patient has coronary artery disease (CAD); furthermore, among CAD patients, they indicate more severe and extensive disease, placing these patients at higher risk for future cardiac events. Indeed, in studies with no obvious perfusion defect yet with serious CAD--for example, balanced ischemia--it can be these high-risk findings that necessitate invasive intervention.
  
  
  CONCLUSIONS
  Besides reversible perfusion defects, such findings include increased pulmonary radiotracer uptake, transient cavity dilatation, increased end-diastolic or end-systolic volume, decreased post-stress ejection fraction, and increased right ventricular tracer uptake on stress images. The pathophysiology underlying these findings is clearly different as they do not always occur together, and each independently predicts more severe and extensive CAD. In the current review, these findings are defined and their significance in diagnosing patients with suspected or known CAD is discussed.
authors.affiliation: Cardiology Section, Nuclear Medicine, VA Boston Healthcare System and Harvard Medical School, 2C-120, 1400 VFW Parkway, Boston, MA 02132, USA. John.Higgins@va.gov
authors.forename: John P
authors.initials: JP
authors.lastname: Higgins
authors.forename: Johanna A
authors.initials: JA
authors.lastname: Higgins
authors.forename: Gethin
authors.initials: G
authors.lastname: Williams
mesh_terms: D009202:Cardiomyopathies / Q000000981:diagnostic imaging*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005080:Exercise Test / Q000379:methods*; D006801:Humans; D011379:Prognosis; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*