Effects of age on ventricular-vascular coupling

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Gerontology

Background:

• The aging process significantly affects cardiovascular function.
• Understanding age-related changes in arterial properties is crucial for cardiovascular health.
• The interrelation between arterial mechanics and cardiac performance changes with age.

Purpose of the Study:

• To investigate the effects of age on the relationship between arterial physical properties and left ventricular performance.
• To analyze how aortic input impedance and cardiac output are modified by aging.

Main Methods:

• Studied 45 healthy subjects aged 19-62 years.
• Measured ascending aortic pulsatile pressure and blood flow velocity using a multisensor catheter.
• Determined cardiac output via green dye or Fick method.

Main Results:

• Heart rate and end-diastolic aortic pressure remained constant with age.
• Aortic systolic, mean, and pulse pressures, along with aortic radius, increased with age.
• Peripheral resistance increased by 37% and characteristic impedance by 137% with age.
• Impedance spectra showed greater fluctuations in older subjects, indicating increased aortic stiffness and decreased peripheral vascular bed cross-section.

Conclusions:

• Aging leads to increased aortic stiffness and peripheral resistance.
• These arterial property changes with age contribute to increased pulse wave velocity and wave reflection.
• The study highlights significant age-related alterations in cardiovascular mechanics.