Asymmetric septal hypertrophy and sympathetic overactivity in normotensive hemodialyzed patients.

Sympathetic activity has been evaluated in 23 chronic uremic normotensive patients on long-term hemodialysis. M-mode and bidimensional echocardiographic finding of asymmetric septal hypertrophy (ASH) was shown in seven (30.4%). Sympathetic function was assessed by determining arterial plasma norepinephrine (plasma NE) and epinephrine (plasma E) in supine and upright positions, both before and after dialysis. After dialysis standing caused a significant increase in plasma NE levels in the patients with ASH in comparison to the patients without ASH and the control group. A significant decrease in mean blood pressure (mBP) and a sharp heart rate (HR) increase were detected in the patients without ASH, whereas mBP and HR were unchanged in the patients with ASH. Predialysis serum creatinine and fasting triglycerides were found to be significantly higher in the group with ASH. These results suggest that sympathetic overactivity may play a role in the development of interventricular septum hypertrophy. This increased neurosympathetic responsiveness is probably related to the counteraction of the postural dialysis-induced hypotension.