Abstract 18465: The Kinetic Energy of Left Ventricular Ejection Flow During Late Systole Produces Inertia Force of Late Systolic Aortic Flow and Good Left Ventricular Early Diastolic Function
Background: Inertia force of late systolic aortic flow (IF), which plays a substantial role for the coupling between left ventricular (LV) contraction and relaxation, may depend on the kinetic energy of ejecting flow (KE) during late systole (KE-LS). Good LV contraction generated much greater KE during early systole (KE-ES) and the KE-ES should affect the KE-LS. We investigated whether the KE-ES and -LS obtained using Vector Flow Mapping (VFMTM, Hitachi-Aloka) had any relationships with both IF and LV relaxation parameters invasively obtained.
Method: Study subjects were 30 patients who underwent diagnostic cardiac catheterization and echocardiography on the same day. Conventional color Doppler images were acquired in the apical 3-chamber view. KE was obtained using the commercially available software (Hitachi-Aloka) (Figure). We divided the LV ejection time into 3 equal phases, then the KE was computed as a sum of KE values frame by frame basis around ES and LS; The ES was defined as the first one-third of ejection time and LS as the last one. In cardiac catheterization, LV pressure (LVP) was obtained using a catheter-tipped micromanometer. First derivative of LVP (dP/dt) and the time constant τ of LVP during isovolumic relaxation were computed. From LVP-dP/dt relationships (phase loop), IF was determined.
Results: There was a significant correlation between KE-ES and KE-LS (r=0.62, p<0.001). Though the KE-ES related significantly with the IF (r=0.63, p<0.001), it did not relate significantly with relaxation parameters. On the other hand, the KE-LS had significant correlations with the IF, peak negative dP/dt and time constant τ (r=0.72, p<0.001, r=0.51, p=0.004 and r=-0.64, p<0.001, respectively).
Conclusion: These findings indicate that noninvasively obtained KE-LS can be used as a surrogate of the invasively obtained IF which is produced by good LV early systolic function. A greater KE-LS may be a parameter of good systolic and early diastolic LV function.
Author Disclosures: J. Yamamoto: None. K. Wakami: None. S. Kikuchi: None. S. Murai: None. H. Fujita: None. T. Sugiura: None. T. Goto: None. N. Ohte: None.
- © 2016 by American Heart Association, Inc.