Background: It has been established that the stiffness of large arteries has a dependency on acute heart rate (HR) changes. However, possible mechanisms behind this HR dependency are harder to establish. Aims: To explore a plausible mechanism by which HR exerts an influence on arterial stiffness. Methods: Using a computerized transmission line model of the human arterial tree, effects of HR on aortic arch to femoral pulse wave velocity (afPWV) were determined with elasticity of the arterial segments modelled with varying degrees of frequency dependence between 0 to 20 Hz. Magnitude of the elasticity was varied as a proportion of the particular segment’s static elastic modulus. Results: In scenarios in which the arterial wall elasticity had low to zero frequency dependence, afPWV was shown to decrease with HR. As the degree of frequency dependence increased, an increase in afPWV with increasing HR was observed. The critical frequency, defined as the frequency where arterial wall elasticity reached 80% of the static elastic modulus, above which HR was shown to positively influence afPWV, was approximately 3 Hz. The change in afPWV with increasing HR plateaued at around 0.06 m/s per 10 bpm increase in HR as the degree of frequency dependence was increased to above 9 Hz. Conclusion: The magnitude of the frequency dependency of arterial wall elasticity alters measures of large arterial stiffness across physiological ranges of HR. This could be a partial mechanism through which large artery stiffness changes with HR. Physiological studies are required to confirm this mechanism.
|Number of pages||1|
|Publication status||Published - 2017|
|Event||38th Annual Scientific Meeting of the High Blood Pressure Research Council of Australia - Hobart, Australia|
Duration: 7 Dec 2016 → 10 Dec 2016