Hypertension and atherosclerosis are associated with reduced arterial
compliance, which is the principal component that reflects the dynamic
behavior of the arterial system. Hence, change in arterial compliance
has been used as a compass of arterial wall properties, as well as an
effective parameter for assessing therapeutic treatment efficacy. The
arterial compliance-blood pressure loop concept is introduced here fo
r assessment of arterial function. Aortic pressure and flow were measu
red in experimental dogs during normal and acute hypertension. The com
pliance-pressure loops were constructed from pulsatile blood pressure
waveforms and the corresponding compliances. The features of the loop
are that, for any given heart beat, arterial compliance is seen to be
maximal in early systole to facilitate ventricular ejection, complianc
e decreasing during the remainder of systole owing to increased blood
pressure and reduced aortic flow, compliance in diastole increasing as
pressure declines. The arteries are stiffer with reduced compliance i
n hypertension. Thus, the compliance-pressure loop can provide an effe
ctive characterization of the dynamic behavior of the arterial system
in terms of pressure-flow relation and blood vessel properties.