Impact of left ventricular mechanical synchrony on systolic function assessed by gated myocardial perfusion imaging

This study aimed to investigate the relationship between left ventricular phase analysis parameters and Peak Emptying Rate (PER) with ejection fraction (EF); to evaluate the role of PER in predicting early systolic dysfunction; and to examine how these parameters are affected by the severity of coronary artery disease (CAD) in patients with ischemia or infarction detected by gated myocardial perfusion scintigraphy (gMPS).

Data from 430 patients who underwent myocardial perfusion scintigraphy for confirmed or suspected CAD were retrospectively analyzed. Based on perfusion defect scores, patients were categorized into three groups: normal (142 patients, SSS ≤ 3), ischemia (140 patients, SSS ≥ 4, reversible defect), and infarction (148 patients, SSS ≥ 4, fixed defect). Systolic and diastolic functional parameters of the left ventricle (EF, EDV, ESV, PER, PFR, TPFR) and synchrony indices (phase standard deviation [SD], histogram bandwidth [HBW]) were measured and compared across groups.

EF values (65, 60, and 43%) and PER values (3.15, 2.94, and 2.06 s^-¹) progressively decreased from the normal to the ischemia and infarction groups, with statistically significant differences among groups (p < 0.001). Synchrony indices (SD and HBW) increased markedly, especially in the infarction group (mean HBW: 60.86-75.01 - 149.31; p < 0.001). In both ischemia and infarction groups, significant correlations were observed between synchrony (HBW) and systolic (EF, PER) as well as diastolic (PFR, TPFR) parameters, with the strongest associations in the infarction group (p < 0.001).

Progressive coronary artery disease is associated with worsening left ventricular systolic and diastolic function, along with impaired mechanical contraction synchrony. PER may serve as a valuable scintigraphic parameter for improving the diagnostic assessment of left ventricular systolic function.