Carotid artery wall mechanics in young males with high cardiorespiratory fitness

Abstract

The influence of cardiorespiratory fitness on arterial stiffness in young adults remains equivocal. Beyond conventional measures of arterial stiffness, two-dimensional strain imaging of the common carotid artery (CCA) provides new information related to the intrinsic properties of the arterial wall. Therefore, the aim of this study was to assess the effect of cardiorespiratory fitness on both conventional indices of CCA stiffness and two-dimensional strain parameters, at rest and after a bout of aerobic exercise in young, healthy men. Short-axis ultrasound images of the CCA were recorded in 34 healthy men {22 years old [95% confidence interval (CI), 19, 22]} before and immediately after 5 min of aerobic exercise (40% of maximal oxygen consumption). Images were analysed for arterial diameter, peak circumferential strain (PCS) and peak systolic and diastolic strain rates (S-SR and D-SR). Heart rate, systolic and diastolic blood pressure were simultaneously assessed, and Peterson's elastic modulus (E ) and β-stiffness (β ) were calculated. Participants were separated post hoc into moderate- and high-fitness groups [maximal oxygen consumption, 48.9 (95% CI, 44.7, 53.2) versus 65.6 ml kg min (95% CI, 63.1, 68.1), respectively; P < 0.001]. The E and β were similar between groups at baseline (P > 0.13) but were elevated in the moderate-fitness group postexercise (P < 0.04). The PCS and S-SR were elevated in the high-fitness group at both time points [3.0% (95% CI, 1.2, 4.9), P = 0.002, and 0.401 s (95% CI, 0.085, 0.72), P = 0.02, respectively]. No group differences were observed in CCA heart rate, systolic or diastolic blood pressure or D-SR throughout the protocol (P > 0.05). Highly fit individuals exhibit elevated CCA, PCS and S-SR, which might reflect training-induced adaptations that help to buffer the increase in pulse pressure and stroke volume during exercise.

The influence of habitual endurance exercise on carotid artery strain and strain rate in young and middle‐aged men

“…Although several previous studies have demonstrated that regular exercise attenuates the age-related increase in β-stiffness and aPWV (Tanaka et al, 2000;Vaitkevicius et al, 1993), those investigating the effect of exercise in young, healthy individuals report far less consistent results (Heydari et al, 2013;Kakiyama et al, 2005;Montero et al, 2017;Pugh et al, 2018;Tanaka et al, 2000). However, the findings of the present study imply that,like PCS and S-SR, the positive influence of habitual exercise on E p , β-stiffness and aPWV is similar in young and middle-aged males.…”

“…Power analyses of CCA 2D‐Strain parameters were conducted a priori by sampling data from two separate studies, one investigating the effect of ageing on 2D‐Strain parameters in untrained individuals (Bjällmark et al., 2010) and the other investigating the effect of high CRF on 2D‐Strain parameters in young men (Pugh et al., 2018). A mean difference in PCS of 3.8% (Cohen's d effect size = 4.19) was detected between young and old individuals, whereas a mean difference of 2.3% ( d = 0.7) was detected between highly and moderately fit young men.…”

The endurance athlete's circulation: Ultra-risky or a long road to safety?

“…Myocardial deformation like torsion/twist, and Carotid-Artery-Longitudinal-Motion (CALM) as well as two-dimensional arterial circumferential strain are amongst those novel parameters. For example, it is possible that one-dimensional measurements like cIMT and conventional measures of local stiffness miss adaptations at distinct regions of the arterial wall circumference that can only be captured by a full 360 • assessment like circumferential strain and strain rate [18,19]. The addition of CALM measurements has the potential to determine the impact of altered carotid structure on arterial wall mechanics [20].…”

Electrocardiogram-Based Timings Cause Systematic Errors in Vascular Strain Measures: A Method for Error Correction and Estimation of Pulse Transit Time

“…Speckle-tracking ultrasonography (STE) has been applied to the assessment of circumferential strain (ɛ) and strain rate (SR) of the common carotid artery (CCA). [1][2][3][4][5] Originally developed for echocardiography, 6 the analysis of ɛ is tethered to key points of the electrocardiogram (ECG). Thus, to prevent measurement drift STE software assumes no deformation (i.e 0% ɛ) at the start of the cardiac cycle defined by the QRS wave.…”

“…All images were acquired by the same sonographer using a Vivid IQ ultrasound machine with a 6-13 MHz linear transducer (GE Healthcare, Cambs, UK), at 106.9 fps. Images were analysed as previously detailed 1,3,5 using EchoPac software (GE Healthcare, Cambs, UK). The resulting data files were further analysed by applying a 1000-point cubic spline to either the ɛ or SR data, which was used to identify raw and corrected peak ɛ (outlined below), and TTP.…”