Cardiovascular Effects of Ageing

Describe the cardiovascular changes that occur with ageing.

CVS effects of ageing can be divided into cardiac, vascular, and autonomic changes:

• Cardiac changes
  • Decreased receptor density and number
  • Decreased maximum heart rate
    Due to fibrosis of the SA node causing reduced pacemaker cell number and function, and reduction in catecholamine receptor density.
    • $Maximum \ heart \ rate \approx 220 - Age$
  • Decreased inotropy
    Minor.
  • Increased reliance on atrial kick
    Reduced ventricular compliance increases the reliance on atrial kick to achieve adequate preload.
  • Decreased diastolic compliance
    • Due to hypertrophy from increased afterload

• Vascular changes
  • Reduced compliance
    Due to loss of elastic tissue in the large arteries.
  • Increased SVR
    Reduced compliance results in increased vascular resistance.
  • Reduced endothelial cell function (decreased NO)
    Impairs the ability of the vascular tree to adapt to changes in pressure/volume leading to:
    • Elevated SBP
    • Reduced DBP
      Reduced elastic recoil causes diastolic run off and a fall in diastolic blood pressure.
  • Reduced catecholamine receptor density
    Reduced responsiveness to (and increased number of) circulating catecholamines.

• Autonomic
  • Impaired autonomic function
    Due to decreased catecholamine responsiveness.
  • Impaired baroreceptor response
  • Decreased exercise tolerance
    Reliance on preload to maintain cardiac output.

References

1. ANZCA February/April 2016
2. Cheitlin MD. Cardiovascular physiology-changes with ageing. Am J Geriatr Cardiol. 2003 Jan-Feb;12(1):9-13.