Global Longitudinal Strain

ObjectivesTwo-dimensional speckle tracking echocardiography has been considered an angle-independent modality. However, current literature is limited and inconclusive on the actual impact of angle of insonation on strain values. Therefore, the primary objective of this study was to assess the impact of angles of insonation on the estimation of fetal left ventricular and right ventricular global longitudinal strain. Secondarily, the impact of different definitions for angles of insonation was investigated in a sensitivity analysis.MethodsThis is a retrospective analysis of a prospective longitudinal cohort study with 124 healthy subjects. The analyses were based on the four-chamber view ultrasound clips taken between 18+0 and 21+6 weeks of gestation. Angles of insonation were categorized into three groups: up/down, oblique and perpendicular. The mean fetal left and right ventricular and global longitudinal strain values corresponding to these three groups were compared by an ANOVA test corrected for heteroscedasticity.ResultsFetal left and right ventricular global longitudinal strain values were not statistically different between the three angles of insonation (p-value >0.062 and >0.149, respectively). When applying another definition for angles of insonation in the sensitivity analysis, the mean left ventricular global longitudinal strain value was significantly decreased for the oblique compared to the up/down angle of insonation (p-value 0.041).ConclusionsThere is no evidence of a difference in fetal left and right ventricular global longitudinal strain between the different angles of insonation in fetal two-dimensional speckle tracking echocardiography.

ObjectiveEvaluation of left ventricular systolic function using speckle tracking echocardiography is more sensitive than conventional echocardiographic measurement in detecting subtle left ventricular dysfunction in septic patients. Our purpose was to investigate the predictive significance of left ventricular global longitudinal strain in normotensive septic intensive care patients.MethodsThis observational, prospective cohort study included septic normotensive adults admitted to the intensive care unit between June 1, 2021, and August 31, 2021. Left ventricular systolic function was measured using speckle-tracking echocardiography within 24 hours of admission.ResultsOne hundred fifty-two patients were enrolled. The intensive care unit mortality rate was 27%. Left ventricular global longitudinal strain was less negative, which indicated worse left ventricular function in non-survivors than survivors (median [interquartile range], -15.2 [-17.2 - -12.5] versus -17.3 [-18.8 - -15.5]; p -17% (less negative than -17%, which indicated worse left ventricular function) showed a significantly higher mortality rate (39.2% versus 13.7%; p ConclusionImpaired left ventricular global longitudinal strain is associated with mortality and provided predictive data in normotensive septic intensive care patients.

This work presents a modular approach to the development of strain sensors for large deformations. The proposed method separates the extension and signal transduction mechanisms using a soft, elastomeric transmission and a high-sensitivity microelectromechanical system (MEMS) transducer. By separating the transmission and transduction, they can be optimized independently for application-specific mechanical and electrical performance. This work investigates the potential of this approach for human health monitoring as an implantable cardiac strain sensor for measuring global longitudinal strain (GLS). The durability of the sensor was evaluated by conducting cyclic loading tests over one million cycles, and the results showed negligible drift. To account for hysteresis and frequency-dependent effects, a lumped-parameter model was developed to represent the viscoelastic behavior of the sensor. Multiple model orders were considered and compared using validation and test data sets that mimic physiologically relevant dynamics. Results support the choice of a second-order model, which reduces error by 73% compared to a linear calibration. In addition, we evaluated the suitability of this sensor for the proposed application by demonstrating its ability to operate on compliant, curved surfaces. The effects of friction and boundary conditions are also empirically assessed and discussed.

Background and aimsWild-type transthyretin cardiac amyloidosis (ATTRwt-CA) is now increasingly identified as a cause of heart failure in older adults. This study aimed to clarify the morphological and functional alterations of the left ventricle (LV) that define the early stage of this condition.MethodsWe prospectively evaluated 81 patients diagnosed with wild-type ATTR (ATTRwt) amyloidosis (mean age 77 ± 6 years; 88% male), categorized into three groups based on myocardial uptake on radioactive pyrophosphate scintigraphy and histological confirmation: (i) carpal ATTR without cardiac involvement (Group 1, n = 13), (ii) asymptomatic cardiac involvement (Group 2, n = 10) and (iii) overt heart failure (Group 3, n = 58).ResultsCompared with Group 3, Group 1 showed higher absolute global longitudinal strain (GLS) (median 19.0 [13.2-23.8]%, P 0.014 ng/mL) than in those with lower values (13.9 ± 5.6% vs. 7.4 ± 1.8%, P = .046) in Group 1. A basal inferoseptal LS cutoff of 9.1% identified high troponin-T with an area under the curve (AUC) of 0.833 (P = .005), outperforming GLS (AUC 0.306, P = .217), BNP (AUC 0.667, P = .292), and LV ejection fraction (AUC 0.556, P = .743).ConclusionsBasal inferoseptal LS impairment may indicate early cardiac involvement in individuals with carpal tunnel syndrome carrying ATTRwt deposits.