Cardiovascular autonomic neuropathy in HIV infected patients

Objective: To evaluate the presence and extent of autonomic dysfunction in HIV infected individuals of one ethnic group. Design: Prospective, age-sex matched study. Methods: 25 patients (seven asymptomatic (HIV), eight AIDS related complex (ARC), 10 AIDS) and 25 controls were recruited from patients and staff at t he Aga Khan Hospital, Nairobi. Autonomic function was assessed by measureme nt of pulse rate variability on standing, rest, deep breathing, Valsalva ma noeuvre, isometric exercise, cold face test, and mental stress. Blood press ure was measured during standing, supine resting, and on Valsalva manoeuvre . CD4 count was correlated with number of abnormal test results. Results: 21 patients had at least one abnormal test of autonomic function c ompared with one control (p<0.0001). There were significant differences bet ween AIDS patients and controls for supine heart rate (p<0.001), Valsalva r atio (p=0.05), and cold face test (p=0.05), and almost significant results for mental stress (p=0.051). Evidence of autonomic hypersensitivity was fou nd in response to exercise and/or mental stress in some patients with HIV o r ARC. No difference was found in blood pressure measurements. Abnormalitie s in autonomic function occurred at all CD4 counts and all patients with fo ur abnormal tests of heart rate variation had a CD4 count less than 300 x 1 0(6)/l. Conclusions: There is evidence of substantial autonomic dysfunction in AIDS patients compared with controls and mild abnormalities in the majority of HIV infected patients studied irrespective of CD4 count. Autonomic hypersen sitivity may precede loss of function in some cases.