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Introduction: Coronary arteries are exposed to a variety of complex biomechanical forces during a normal cardiac cycle. These forces have the potential to contribute to coronary stent failure. Recent advances in stent design allow for the transmission of native pulsatile biomechanical forces in the stented vessel. However, there is a significant lack of evidence in a human model to measure vessel motion in native coronary arteries and stent conformability. Thus, we aimed to characterize and define coronary artery radial deformation and the effect of stent implantation on arterial deformation.Materials and Methods: Intravascular ultrasound (IVUS) pullback DICOM images were obtained from human coronary arteries using a coronary ultrasound catheter. Using two-dimensional speckle tracking, coronary artery radial deformation was defined as the inward and outward displacement (mm) and velocity (cm/s) of the arterial wall during the cardiac cycle. These deformation values were obtained in native and third-generation drug-eluting stented artery segments.Results: A total of 20 coronary artery segments were independently analyzed pre and poststent implantation for a total of 40 IVUS runs. Stent implantation impacted the degree of radial deformation and velocity. Mean radial deformation in native coronary arteries was 0.1230 mm ± 0.0522 mm compared to 0.0775 mm ± 0.0376 mm in stented vessels (p=0.0031). Mean radial velocity in native coronary arteries was 0.1194 cm/s ± 0.0535 cm/s compared to 0.0840 cm/s ± 0.0399 cm/s in stented vessels (p=0.0228).Conclusion: In this in vivo analysis of third-generation stents, stent implantation attenuates normal human coronary deformation during the cardiac cycle. The implications of these findings on stent failure and improved clinical outcomes require further investigation. [ABSTRACT FROM AUTHOR]

Aims Information is limited regarding the functional correlates of intramural scar burden in myopathic hearts. We aimed to explore the use of speckle tracking echocardiography selectively at three intramural locations, to investigate the variance in cardiac strains and their relationship to contrast-enhanced magnetic resonance imaging-derived scar distribution and global left ventricular systolic function. Methods and results Fifty-nine patients with evidence of myocardial fibrosis on contrast-enhanced magnetic resonance imaging and 18 healthy subjects underwent speckle tracking echocardiography for measuring subendocardial, midmyocardial, and subepicardial strains in longitudinal, circumferential, and radial directions. Patients were divided into three categories of scar distribution: Group A, endocardial and midmyocardial; Group B, midmyocardial and epicardial; and Group C, transmural. When these patients were compared with 18 healthy control subjects, longitudinal left ventricular deformation was attenuated equally for all three groups, whereas circumferential strain was relatively well preserved. On multivariate analysis, circumferential strain and scar burden were independent determinants of left ventricular ejection fraction (R2 = 0.57; P= 0.003 for strain burden and P= 0.01 for scar burden). Conclusion Longitudinal strains are attenuated independent of myocardial scar location. This alteration in left ventricular deformation is associated with circumferential mechanics becoming a key determinant of global left ventricular pump function in myopathic hearts. [ABSTRACT FROM PUBLISHER]

Chronic stress has a deleterious effect on prefrontal lobe functioning. Empirical evidence suggests elevated vagal tone, indexed by elevated heart rate variability (HRV), mitigates the effect of mental stress on frontal lobe function. Here, the mitigating effect of HRV on stress-related decrements in cognitive performance is assessed based on information processing speed (DSST), word fluency and verbal learning task performance. Artifact free electrocardiogram (ECG) data was analyzed from 1420 Hispanic/Latino adults from the Sociocultural Ancillary of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). A 12-lead ECG was used to collect short-term recordings of the root mean square of successive differences in all normal R-peak to R-peak intervals (RMSSD) and the change between adjacent beats and the standard deviation of those intervals (SDNN) as indices of total HRV. As predicted, an interaction emerged for HRV and stress on the task presumed to require the greatest prefrontal lobe involvement, i.e., the DSST. After accounting for sociodemographic factors, chronic stress was associated with better DSST performance amongst individuals at higher quartile of SDNN, but not RMSSD. The paradoxical effect for greater stress exposure on DSST performance may in part be explained by increased speed of information processing and decision making often reported in high-stress cohorts. The nature of this interaction highlights the importance of examining the relationship between stress and cognition across a spectrum of vagal tone. • Paradoxical effect for cumulative life stress on information processing speed • Interaction occurred in Hispanics/Latinos with highest resting heart rate variability. • Data supports ultra-short HRV as transdiagnostic marker of resilience to stress. • Greater Spanish-English word fluency with HRV supports marker of prefrontal lobe function. [ABSTRACT FROM AUTHOR]