ABSTRACT

Gated myocardial perfusion imaging (gMPI) is an established tool for the diagnosis and risk stratification of patients with coronary artery disease (CAD) providing a variety of parameters regarding to perfusion and function of left ventricle (LV). Transient ischemic dilation (TID) is one of them. The presence of TID has been shown as a marker of severe and extensive CAD. The aim of this study was to correlate scintigraphic and angiographic findings of patients with positive TID on their gMPI scans.

Stress-rest gMPI was performed for 27 patients with suspected CAD. TID was equal or higher than 1.03 (TID≥1.03) in all patients. All patients had invasive coronary angiography results during 3 months before or after their SPECT studies. Ejection fraction (EF), end-diastolic and end-systolic volumes (EDV, ESV), TID were calculated. We correlated angiographic results with scintigraphic findings of the patients with positive TID.

We couldn’t find statistical significant difference in functional parameters of the left ventricle between the groups of patients with normal or near normal coronary angiograms and with abnormal angiograms.

TID should be considered a high risk marker in clinical management of patients with suspected or known CAD. But it can also be positive in normal coronary angiograms of conditions such as hypertensive heart disease and hypertrophic cardiomyopathy. Therefore, TID should be correlated with other perfusion and functional parameters of LV to reach the final diagnosis. If it is the only finding, it is reasonable to be cautious while interpreting gMPI.

Keywords: Transient ischemic dilation, gated myocardial perfusion imaging, coronary artery disease.