Impact of mitral geometry and global afterload on improvement of mitral regurgitation after trans-catheter aortic valve implantation.

OBJECTIVE: To assess the impact of mitral geometry, left ventricular (LV) remodelling and global LV afterload on mitral regurgitation (MR) after trans-catheter aortic valve implantation (TAVI). METHODS: In this study, 60 patients who underwent TAVI were evaluated by 3D echocardiography at baseline, 1 month and 6 months after procedure. The proportional change in MR following TAVI was determined by examining the percentage change in vena contracta (VC) at 6 months. Patients having a significant reduction of at least 30% in VC were defined as good responders (GR) and the remaining patients were defined as poor responders (PR). RESULTS: After 6 months of TAVI, 27 (45%) patients were GR and 33 (55%) were PR. There was a significant decrease in 3DE-derived mitral annular diameter and area (P = 0.001), mitral valve tenting area (TA) (P = 0.05), and mitral papillary muscle dyssynchrony index (DSI) (P = 0.05) in the GR group. 3DE-derived LVESV (P = 0.016), LV mass (P = 0.001) and LV DSI, (P = 0.001) were also improved 6 months after TAVI. In addition, valvulo-arterial impedance (ZVA) was significantly higher at baseline in patients with PR (P = 0.028). 3DE-derived mitral annular area (ß: 0.47, P = 0.04), mitral papillary DSI (ß: -0.65, P = 0.012) and ZVA (ß: 0.45, P = 0.028) were the strongest independent parameters that could predict the reduction of functional MR after TAVI. CONCLUSION: GR patients demonstrate more regression in mitral annulus area and diameter after significant decrease in high LVEDP and trans-aortic gradients with TAVI. PR patients appear to have increased baseline ZVA, mitral valve tenting and restriction in mitral valve coaptation. These factors are important for predicting the impact of TAVI on pre-existing MR.

Clinical implications of velocity vector imaging-based two dimensional strain imaging for the evaluation of left ventricular systolic functions.

Two-dimensional (2D) echocardiography is the most common imaging modality used to assess left ventricular (LV) myocardial function. Although the studies revealed useful conclusions, there are some limitations with the conventional measurement of ejection fraction. Two dimensional (2D) strain imaging is newer echocardiographic technique which is utilized for the evaluation of quantitative regional ventricular functions. Velocity vector imaging based- 2D strain imaging is the most recent technology with a few advantages sourced by its software. This review introduces a novel 2D strain imaging technology, explains its fundamental concepts and discusses clinical applications with all the major advantages and limitations.