Parameters:
(1) systolic arterial diameter in cm
(2) diastolic arterial diameter in cm
(3) systolic blood pressure in mm Hg
(4) diastolic blood pressure in mm Hg
When measuring the distensibility of the aorta:
(1) The diameter is measured 3 cm above the aortic valve.
(2) The diastolic diameter is measured at the peak of the QRS wave.
(3) The systolic diameter is measured just after the T wave.
pulse pressure in mm Hg =
= (systolic blood pressure in mm Hg) - (diastolic blood pressure in mm Hg)
arterial distensibility =
= 2 * ((systolic arterial diameter) - (diastolic arterial diameter)) / ((pulse pressure in mm Hg) * (diastolic arterial diameter))
where:
• The units of the distensibility are in (mm Hg)^(-1).
• Distensibility may be reported in (cm^2) / (dyne). 1 mm Hg = 1,333 (dyne) / (cm^2).
Interpretation:
• With increasing atherosclerosis the distensibility of an artery progressively decreases.
