Abstract 14561: Intra Left Ventricular Pressure Gradient Obtained by Vector Flow Mapping is Useful to Assess Left Ventricular Suction and Relaxation
Background: Inertia force of late systolic aortic flow (IF) that is generated by good left ventricular (LV) systolic function enhances LV relaxation. We investigated whether the intra-LV pressure gradient (IVPG) during isovolumic relaxation period (IR) obtained using Vector Flow Mapping (VFM) had any relations with IF and LV relaxation parameters obtained invasively.
Method: Study subjects were consisted of 74 patients who underwent cardiac catheterization. Conventional color Doppler images were acquired in the apical 3-chamber view using an echo equipment Prosound afla10TM (Hitachi-Aloka). We obtained the IVPG-IR using an echo image analyzer (DAS-RS1TM). From the data set of the blood flow velocity vectors, IVPG-IR was computed as shown (Figure). Cardiac catheterization was also performed on the same day. LV pressure (LVP) was obtained using a catheter-tipped micromanometer. First derivative of LVP (dP/dt) and the time constant τ of LVP during IR were computed. From LVP-dP/dt relationships (phase loop), IF was determined. LV end-systolic volume indexed to the body surface area (LVESVI) was computed.
Results: The median of IVPG-IR was -0.22 mm Hg/cm (IQR, -0.35, -0.09). It had a significant correlation with IF (r=-0.67, p<0.001). The absolute value of IVPG-IR significantly related with LVESVI (r=-0.81 with a logarithm curve fitting, p<0.001). IVPG-IR also had significant correlations both with peak negative dP/dt and time constant τ (r=0.62 p<0.001 and r=-0.62, p<0.001, respectively).
Conclusion: Using the VFM, IVPG-IR can be obtained. Using IVPG-IR, the magnitude of LV suction or elastic recoil (a coupling of good LV systolic function and relaxation) can be assessed noninvasively and quantitatively.
Author Disclosures: K. Wakami: None. S. Saiki: None. Y. Kawada: None. K. Muto: None. J. Yamamoto: None. H. Fujita: None. T. Goto: None. T. Sugiura: None. H. Fukuta: None. N. Ohte: None.
- © 2016 by American Heart Association, Inc.