Evaluation of left ventricular blood flow kinetic energy in patients with acute myocardial infarction by 4D flow MRI: a preliminary study

Abstract

Abstract Purpose: To evaluate the intracavity left ventricular (LV) blood flow kinetic energy (KE) parameters using four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) in patients with acute myocardial infarction (AMI). Methods: Thirty AMI patients and twenty controls were examined via CMR, which included cine imaging, late gadolinium enhancement (LGE) and global heart 4D flow imaging. The KE parameters were correlated with the left ventricular end-diastolic volume (LVEDV) to obtain average, minimal, systolic, and diastolic KE as well as the proportion of LV in-plane KE (%). These parameters were compared between the AMI patients and controls and between the two subgroups. Results: Analysis of the LV blood flow KE parameters at different levels of the LV cavity and in different segments of the same level showed that the basal level had the highest blood flow KE while the apical level had the lowest in the control group. There were significant differences in diastolic, systolic and diastolic in-plane KE between the anterior wall and posterior wall (p>0.05). Compared with those in the control group, the average (10.7±3.3 μJ/mL vs. 14.7±3.6 μJ/mL, p<0.001), systolic (14.6±5.1 μJ/mL vs. 18.9±3.9 μJ/mL, p=0.003) and diastolic KE (7.9±2.5 μJ/mLvs. 10.6±3.8 μJ/mL, p=0.018) were significantly lower in the AMI group. The average KE in the infarct segment was lower than that in the noninfarct segment in the AMI group, while the proportion of systolic in-plane KE increased significantly (49.5±18.7 μJ/mL vs. 126.3±50.7 μJ/mL, p<0.001; 61.8%±11.5 vs. 42.9%±14.4, p=0.001). Conclusion: The 4D flow MRI technique can be used to quantitatively evaluate LV regional haemodynamic parameters. There were differences in the KE parameters of LV blood flow at different levels and in different segments of the same level in healthy people. In AMI patients, the average KE of the infarct segment decreased, while the proportion of systolic in-plane KE significantly increased.