Left ventricle geometry, atrial strain, ventricle strain, and hemodynamics across aortic valve before and after transcatheter aortic valve replacements.

INTRODUCTION: Transcatheter aortic valve replacements (TAVRs) has become widespread throughout the world. To date, there are no echocardiographic studies of TAVR patients from Southeast Asia (SEA). We sought to evaluate (1) changes in echocardiographic and strain values pre- and post-TAVR (2) relationship between aortic stenosis (AS) severity and strain values, (3) left ventricle geometry in severe AS, (4) relationship of flow rate to dimensionless index (DVI) and acceleration time (AT), and (5) effect of strains on the outcome. MATERIALS AND METHODS: Retrospective study of 112 TAVR patients in our centre from 2009 to 2020. The echocardiographic and strain images pre (within 1 month), post (day after), and 6 months post-TAVR were analyzed by expert echocardiographer. RESULTS: The ejection fraction (EF) increased at 6 months (53.02 ± 12.12% to 56.35 ± 9.00%) (p=0.044). Interventricular septal thickness in diastole (IVSd) decreased (1.27 ± 0.21 cm to 1.21 ± 0.23 cm) (p=0.038) and left ventricle internal dimension in diastole (LVIDd) decreased from 4.77 ± 0.64 cm to 4.49 ± 0.65 cm (p=0.001). No changes in stroke volume index (SVI pre vs 6 months p=0.187), but the flow rate increases (217.80 ± 57.61 mls/s to 251.94 ± 69.59 mls/s, p<0.001). Global longitudinal strain (GLS) improved from -11.44 ± 4.23% to -13.94 ± 3.72% (p<0.001), left atrial reservoir strain (Lar-S) increased from 17.44 ± 9.16% to 19.60 ± 8.77% (p=0.033). Eight patients (7.5%) had IVSd < 1.0 cm, and 4 patients (3.7%) had normal left ventricle (LV) geometry. There was linear relationship between IVSd and mean PG (r=0.208, p=0.031), between GLS to aortic valve area (AVA) and aortic valve area index (AVAi) (r = - 0.305, p=0.001 and r= - 0.316, p= 0.001). There was also relationship between AT (r=-0.20, p=0.04) and DVI (r=0.35, p<0.001) with flow rate. Patients who died late (after 6 months) had lower GLS at 6 months. (Alive; -13.94 ± 3.72% vs Died; -12.43 ± 4.19%, p=0.001). CONCLUSION: At 6 months, TAVR cause reverse remodelling of the LV with the reduction in IVSd, LVIDd, and improvement in GLS and LAr-S. There is a linear relationship between GLS and AVA and between IVSd and AVA.

Test systems for the biomechanical evaluation of hip protectors: a systematic review.

Various mechanical and biomechanical test systems to evaluate the effectiveness of hip protectors designed to prevent hip fracture as a result of falls were examined in this review. The articles considered were selected systematically. The effect of differences in design criteria was demonstrated, and it was observed that the impact energy employed during testing dramatically affects the performance of the hip protector. Over the past three decades, researchers have continuously experimented with various systems to determine the efficacy of various hip protectors. The primary aim has been to make informed decisions in optimizing hip protector design. This article provides a systematic review of various test systems employed in the determination of the biomechanical efficacy of hip protectors. A systematic literature search was carried out, and 28 relevant articles were included to demonstrate the effect of test systems in the evaluation of the biomechanical effectiveness of hip protectors. Methodological studies illustrated the appropriate use of impact testing systems for the simulation of hip anatomy and fall dynamics in evaluating the effectiveness of hip protectors in preventing a hip fracture. This systematic review has demonstrated the effect of the variability of test systems on the evaluation of impact attenuation by various hip protectors. The lack of standardized test systems accounts for the inconsistencies in the test results of the efficacy of hip protectors. This has been a major challenge in the efforts of researchers to optimize the interventions. The standardization of test systems may require needed improvements immediately as opposed to the development of new interventions in order to ensure that only hip protectors with adequately proven efficacies are deployed for clinical trials or for the protection of the hips of vulnerable individuals from sideways impact.