Association Between Carotid Arterial Strain and Heart Rate Variability in Older Age

Area of Science:

• Cardiology
• Vascular Biology
• Gerontology

Background:

• Loss of normal heart rate variability (HRV) is a predictor of mortality.
• Arterial stiffness and impaired baroreceptor reflex function are implicated in cardiovascular autonomic dysfunction.

Purpose of the Study:

• To investigate the association between carotid arterial strain (CAS) and HRV in an older population.
• To determine if increased vascular stiffness, indicated by CAS, relates to cardiac autonomic dysfunction and reduced HRV.

Main Methods:

• Utilized ultrasound to measure CAS and carotid intima-media thickness (cIMT) in 896 participants (aged 60-64).
• Assessed time- and frequency-domain HRV indices using a 12-lead tachogram.
• Employed generalized linear models with confounder adjustment and sensitivity analyses.

Main Results:

• CAS was significantly associated with multiple HRV markers, including SDNN, RMSDD, HRV triangular index, and HF/LF power.
• These associations remained significant after adjusting for confounders and in sensitivity analyses excluding participants with cardiovascular disease.
• Key associations persisted regardless of cIMT, hypertension, or stroke.

Conclusions:

• Carotid stiffening (CAS) in older age is associated with a loss of HRV.
• This relationship may be mediated by an impaired baroreceptor response, independent of atherosclerotic vascular disease.
• Findings highlight the link between vascular stiffness and cardiac autonomic regulation in aging populations.