The effect of vasodilator therapy on the limb circulation in hypertension.

The effect of vasodilator drugs on limb circulation was investigated in 59 hypertensive patients. Forty-six of them suffered from obliterative arterial disease, too. The drugs administered were: hydralazine, nitroglycerine and sodium nitroprusside. Isotope dilution method was employed to assess limb blood flow before and after acute treatment. Limb vascular resistance was calculated from the limb blood flow and the mean blood pressure. A marked increase in limb blood flow and decrease in vascular resistance following vasodilator treatment were observed in hypertensive patients suffering from obliterative arterial disease. No difference was found between the various vasodilators investigated. Normotensive patients with arterial disease exhibited the same response to a lesser degree. In exceptional cases, where blood pressure dropped abruptly, limb blood flow decreased and limb vascular resistance increased. The data show that vasodilator therapy in hypertension results in diminished limb vascular resistance and improved limb circulation in patients with obliterative arterial disease.