Abstract
Cardiac function early (less than 4 weeks) in the course of experimental renal hypertension was investigated. In 11 male mongrel dogs, one kidney was wrapped in silk to produce two-kidney, one-wrapped hypertension. Two weeks later, the contralateral kidney was removed. Five sham-wrapped and then contralaterally-nephrectomized dogs served as controls. M-mode left ventricular (LV) echocardiograms were recorded twice weekly in all dogs for 4 weeks before and for 2 weeks after wrapping (or sham-wrapping) and for 4 weeks after nephrectomy. In the 11 hypertensive dogs, mean arterial pressure (MAP) rose from 127 mm Hg (mean) to 143 two weeks after wrapping (p<0.05) and to 185 two weeks after nephrectomy (p<0.001). The fractional shortening of the left ventricle (%D) of hypertensive dogs was increased (9% maximum, mean, p<0.01) for 2 weeks after wrapping and for one week after nephrectomy. Two weeks after wrapping, LV end-systolic wall stress calculated from femoral artery peak systolic pressure, end-systolic dimension and wall thickness was unchanged, suggesting that increased myocardial contractility accounted for the findings. In normotensive control dogs, there were no echocardiographic changes during the study.