Unilateral Renal Hemodynamics and Characteristics of Dye-Dilution Curves in Patients with Essential Hypertension and Renal Disease

To gain information concerning cardiorenal hemodynamics in essential hypertension, renal vascular disease, and chronic glomerulonephritis, indocyanine green was used to determine renal blood flow (RBF), renal blood volume (RBV), mean transit time (MTT), appearance time (AT), buildup time (BT), and passage time (PT), in 83 kidneys of 47 hypertensive patients and eight volunteers. Cardiac output (CO) was concurrently measured. Dye, injected into the renal artery, while renal venous blood was drawn through a cuvette densitometer, gave a reproducible curve within 7.7%±2% with multi-exponential washout. RBF (dye) agreed closely (dye/PAH ratio=1.04) with para-aminohippurate (PAH) estimated renal blood flow in 18 kidneys. The RBF and RBV were significantly higher in patients with essential hypertension with high cardiac output than in those with normal cardiac output and were reduced significantly in patients with renal vascular diseases, although CO was the same. The contour of dye curves differed between the various diseases due to significant differences in BT and PT. AT and BT were significantly prolonged in patients with malignant hypertension, renal artery stenosis, and chronic glomerulonephritis. BT was significantly shorter in essential hypertensives than in normals. PT and MTT were significantly longer in malignant hypertensive, renal artery stenosis, and chronic glomerulonephritis groups. Passage time was significantly longer in glomerulonephritics than in nephrosclerotics. The procedure has value for the study of human renal circulation.