Aortic compliance was lower in hypertensive subjects (0.80 ml/mm Hg) than in normotensive subjects (1.47 ml/mm Hg), but increased to equal or greater levels during nitroprusside infusion.
Observational
Does nitroprusside infusion improve aortic compliance in hypertensive subjects compared to normotensive controls?
Aortic compliance is reduced in hypertensive patients partly due to excess smooth muscle tone, which can be reversed with nitroprusside infusion.
Absolute Event Rate: 0.8% vs 1.47%
Aortic compliance in normotensive and hypertensive Chinese subjects undergoing diagnostic cardiac catheterization was compared by using a newly described method that allows for determination of the pressure dependence of compliance if one assumes a value for the exponential coefficient of the pressure-volume relation of the large arteries. Under baseline conditions in the normotensive and hypertensive groups at mean aortic pressures of 96.3 and 128.6 mm Hg, aortic compliance averaged 1.47 and 0.80 ml/mm Hg, respectively. Compliance in the hypertensive group at a diastolic pressure of 99.4 mm Hg (which was nearly equal to the mean normotensive pressure) was 1.072 ml/mm Hg--still significantly lower than in the normotensive group. During nitroprusside infusion, however, the compliances in the hypertensive group increased to levels equal to or greater those in the normotensive group. Thus, these data confirm that aortic compliance is lower in hypertensive than in normotensive humans. They further demonstrate that the lower compliance cannot be attributed entirely to the elevated blood pressure, suggesting that excess smooth muscle tone may be partly responsible.
Liu et al. (Tue,) conducted a observational in Hypertension. Hypertension vs. Normotension was evaluated on Aortic compliance under baseline conditions (ml/mm Hg). Aortic compliance was lower in hypertensive subjects (0.80 ml/mm Hg) than in normotensive subjects (1.47 ml/mm Hg), but increased to equal or greater levels during nitroprusside infusion.