Intraventricular pressure difference estimation based on blood speckle tracking—invasive validation and early clinical application

Figure 1. Invasive IVPD vs. IVPD based on BST in the experimental laboratory setting. Apical left ventricular four chamber BST images (A) and invasive pressure recordings from two micromanometer catheters in the left ventricle (B) were simultaneously acquired. Invasive IVPD was calculated as the instantaneous pressure difference between the apical catheter (blue graph) and basal catheter (green graph) (B, D). IVPD in early diastolic filling from BST (C) was compared with the invasively measured IVPD (D).

Figure 2. IVPD analysis based on BST in the clinical setting. (A) Two-dimensional pressure difference map from PyUSView at peak IVPD in early diastole in one of the controls. Blue colour depicts negative pressure differences and red colour depicts positive pressure differences in the basicoapical direction. IVPD is calculated from base to apex along the spline curve. (B) Graphical display of IVPD along the spline curve through the heart cycle. The spline curve is static and is chosen to cover the entire length of the LV from base to apex in the image frame representing peak early diastolic IVPD. The IVPD curve therefore represents exact IVPD from base to apex only in the frame of peak IVPD. (C) Two-dimensional blood flow velocities from PyUSView at peak mitral valve E-velocity (MVE) from the same BST-acquisition and heart cycle used in panel A. (D) Peak IVPD precedes peak MVE (in this participant peak IVPD preceded peak MVE by 33.5 ms).

Figure 3. Comparisons between IVPD from BST and invasive measurements in the experimental laboratory setting.

Figure 4. Subject enrolment.

Figure 5. IVPD in controls and patients with UVH (A) box plot demonstrating significantly reduced IVPD in patients with UVH compared with controls. (B) Variation of IVPD with age in controls and UVH including the corresponding regression line and its 95% confidence interval (shadowed area).