Hemodynamic and energetic aspects of the left ventricle in patients with mitral regurgitation before and after mitral valve surgery

Abstract

Background: The role of intracardiac blood flow behavior within the context of manifestation and interventional success in patients with mitral regurgitation is unknown to date. The present study aims to assess left ventricular blood flow behavior characterized by kinetic energy (KE) in patients with mitral regurgitation before and after mitral valve surgery.

Methods: Patients with mitral regurgitation (mean age 56 ± 9 years) and the necessity for mitral valve repair (n = 6) or biological valve replacement (n = 4) received cardiac magnetic resonance before and after surgery and were compared with a group of healthy volunteers (n = 7; mean age 27 ± 7 years). Volumetric data and KE of the left ventricle were obtained for all subjects. KE normalized and nonnormalized to volume was calculated from four-dimensional flow magnetic resonance imaging. Mean KE and KE peaks (systolic, early-diastolic and late diastolic), and end-systolic phase duration were considered.

Results: End-diastolic, end-systolic and stroke volume were significantly higher in patients with mitral regurgitation than in healthy volunteers (P = 0.00, 0.01, and 0.00, respectively) and decreased significantly after surgery (P = 0.00, 0.01, and 0.00, respectively). A significant postoperative decrease of mean KE, systolic and early-diastolic KE peaks was observed (P = 0.01, 0.02, and 0.01, respectively). Late-diastolic KE peak remained high in postoperative patients (P = 0.58).

Conclusion: Intracardiac blood flow as characterized by measurements of KE is altered in patients with mitral regurgitation. Physiological flow conditions appear to not fully be restored with mitral valve surgery.

Keywords: 4D flow magnetic resonance imaging; intracardiac blood flow; kinetic energy; mitral regurgitation.