HRV and arterial stiffness Flashcards
what are the components of arterial stiffness?
Structural changes and functional changes
what are the two types of arteries?
Elastic and muscular
what is the function of the aorta during systole?
Aorta stretches to “store” blood. This allows some blood to be propelled and some to be stored to dampen the overall blood pressure
what is the function of the aorta during diastole?
The aorta recoils and releases the blood it stored in order to provide a steady flow of blood to the systemic circulation
Differences between muscular and elastic arteries
Muscular arteries have more Smooth muscle cells, thicker walls and less elastic fibres.
Muscular arteries also have smaller lumens
How does the structure of muscular arteries relate to their function
The thick layer of Smooth muscle cells allows the artery to provide powerful vasoconstriction and dilation in order to change the amount of blood being delivered as needed.
How does artery structure change with ageing
Elastin degrades, collagen deposits increase and calcification occurs. This causes arterial stiffness
What is the function of the endothelium
Protects smooth muscle cells from contaminants in the blood. Also releases nitric oxide to vasodilate, and endothelin to vasoconstrict.
What characterises endothelial dysfunction
Impaired function, loss of Nitric oxide. Favouring of vasoconstriction. Leading to hypertension.
How can we assess arterial stiffness
Many methods but two non-invasive methods are:
Pulse wave velocity (the gold standard) and Pulse wave analysis
Procedure of Pulse wave analysis
Sensor is placed on the radial artery
Pulse wave is detected and recorded
Through a validated system, this provides information on arterial
stiffness
Timing of the reflected waves arriving at the aorta
During systole vs diastole
Pressure ‘seen’ by the heart
‘Central blood pressure’
