Arterial compliance has been recognized to be pressure-dependent. Its varia tion due to changing systolic and diastolic blood pressures in hypertension and subsequent vasodilation has not been investigated. The authors examined this aspect by combining an animal experiment and a recently established nonlinear windkessel model of the arterial system that incorporates a pressure-dependent arterial compliance, C(P). Aortic pressure and flow were simultaneously mea sured in experimental dogs during control and during methoxamine-induced hypertension and nitroprusside-induced vasodilation. A numerical procedure was implemented to compute the nonlinear compliance and account for the pressure dependence. Results show that within the cardiac cycle, C(P) reached its maximum at end-systole and increased in diastole when diastolic aortic pres sure decayed. The magnitude of C(P) and its variation within the cardiac cycle was larger at low pressures, while the reverse was found when blood pressure was high. C(P) decreased significantly in hypertension and increased during subsequent vasodilation.
All Science Journal Classification (ASJC) codes
- Cardiology and Cardiovascular Medicine