Assessment of transient left ventricular dilation ratio via 2-day dipyridamole Tc-99m sestamibi nongated myocardial perfusion imaging.
BACKGROUND
The definition of an abnormal transient ischemic dilation (TID) ratio may be different according to stress type, type of isotope, and imaging protocols. The aim of this study was to derive the normal threshold and assessment of the TID ratio via 2-day dipyridamole stress/rest technetium 99m sestamibi myocardial perfusion single photon emission computed tomography (MPS).


RESULTS
We performed 2-day dipyridamole stress/rest Tc-99m sestamibi MPS in 665 patients. The TID ratio was calculated automatically with the Emory Cardiac Toolbox. The upper limit of normal (1.19) for the TID ratio was derived from 131 patients with a low (<5%) likelihood of coronary artery disease as mean + 2 SDs. Patients with complete or partial reversible defects or multivessel-type or left anterior descending artery (LAD) territory perfusion abnormalities had higher TID ratios than the other patients. These patients had a higher frequency of an abnormal TID ratio (>1.19) as well. Binary logistic regression analysis showed that ischemia and LAD territory perfusion abnormality were independent predictors of an abnormal TID ratio.


CONCLUSIONS
The threshold for an abnormal TID ratio via 2-day post-dipyridamole stress/rest Tc-99m sestamibi MPS was greater than 1.19. By use of this protocol, TID is not uncommon and it is related to a greater amount of ischemic burden as well as multivessel-type or LAD territory perfusion abnormality.
Department of Nuclear Medicine, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. vrdabbagh@yahoo.com
Vahid Reza Dabbagh
VR
Kakhki
Ramin
R
Sadeghi
Seyed Rasoul
SR
Zakavi
D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis; D004176:Dipyridamole / Q000494:pharmacology*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D010477:Perfusion; D012984:Software; D017256:Technetium Tc 99m Sestamibi / Q000494:pharmacology*; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods*; D014665:Vasodilator Agents / Q000494:pharmacology; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000473:pathology*
D014665:Vasodilator Agents; D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi