Background: Myocardial infarction (MI) leads to complex changes in left ventricular (LV) haemodynamics that are
linked to clinical outcomes. We hypothesize that LV blood flow kinetic energy (KE) is altered in MI and is associated
with LV function and infarct characteristics. This study aimed to investigate the intra-cavity LV blood flow KE in
controls and MI patients, using cardiovascular magnetic resonance (CMR) four-dimensional (4D) flow assessment.
Methods: Forty-eight patients with MI (acute-22; chronic-26) and 20 age/gender-matched healthy controls
underwent CMR which included cines and whole-heart 4D flow. Patients also received late gadolinium
enhancement imaging for infarct assessment. LV blood flow KE parameters were indexed to LV end-diastolic
volume and include: averaged LV, minimal, systolic, diastolic, peak E-wave and peak A-wave KEiEDV. In addition, we
investigated the in-plane proportion of LV KE (%) and the time difference (TD) to peak E-wave KE propagation from
base to mid-ventricle was computed. Association of LV blood flow KE parameters to LV function and infarct size
were investigated in all groups.
Results: LV KEiEDV was higher in controls than in MI patients (8.5 ± 3 μJ/ml versus 6.5 ± 3 μJ/ml, P = 0.02).
Additionally, systolic, minimal and diastolic peak E-wave KEiEDV were lower in MI (P < 0.05). In logistic-regression
analysis, systolic KEiEDV (Beta = − 0.24, P < 0.01) demonstrated the strongest association with the presence of MI. In
multiple-regression analysis, infarct size was most strongly associated with in-plane KE (r = 0.5, Beta = 1.1, P < 0.01). In
patients with preserved LV ejection fraction (EF), minimal and in-plane KEiEDV were reduced (P < 0.05) and time
difference to peak E-wave KE propagation during diastole increased (P < 0.05) when compared to controls with
normal EF.
Conclusions: Reduction in LV systolic function results in reduction in systolic flow KEiEDV. Infarct size is
independently associated with the proportion of in-plane LV KE. Degree of LV impairment is associated with TD of
peak E-wave KE. In patient with preserved EF post MI, LV blood flow KE mapping demonstrated significant changes
in the in-plane KE, the minimal KEiEDV and the TD. These three blood flow KE parameters may offer novel methods
to identify and describe this patient population.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)