Association Between Stress-Induced Left Ventricular Diastolic Dysfunction and Ischemic Heart Disease in Myocardial Perfusion Imaging

Background: Myocardial perfusion imaging (MPI) via gated single-photon emission computed tomography is an effective tool in the evaluation of left ventricular (LV) perfusion and function. The purpose of this study was to determine the association between stress-induced left ventricular diastolic dysfunction (LVDD) and ischemic heart disease (IHD) via MPI. Methods: The present study recruited 103 patients, all of whom underwent a standard 2-day stress/rest gated MPI study according to predefined protocols. Perfusion quantitative and semiquantitative indices and diastolic functional parameters were recorded. Results: The study population comprised 88 male patients (85%) and 15 female patients (15%) at a mean age of 56.3 +/- 10.7 years. The thresholds of stress-induced LVDD were calculated as post-stress to rest differences in diastolic parameters and defined as a reduction of 0.21 end-diastolic volumes per second (EDV/s) in the peak filling rate (PFR), an increase of 0.32 in the PFR2/PFR ratio, and an increase of 25 milliseconds of time-to-peak filling. The patients were categorized into 2 groups based on the presence or absence of stress-induced LVDD. The comparison of perfusion parameters depicted no significant changes between the 2 groups (all P-values >0.05). No significant differences were also detected concerning IHD burden (P =0.714). Conclusions: Although LV diastolic dysfunction is deemed one of the earliest indicators of coronary artery disease, we found no significant association between stress-induced LVDD and the burden of IHD.