Power spectral analysis of heart rate variability in HIV-infected and AIDS patients

Abstract

Background: In HIV-infected patients the risks for cardiovascular disease are multifactorial. Autonomic dysfunction has been detected in the early phase of HIV infection as well as in AIDS patients with advanced cardiomyopathy.

Methods: Forty AIDS patients receiving highly active antiretroviral therapy (HAART), 40 HIV+ naïve of HAART, and 40 control subjects were studied. Computerized analysis of heart rate variability was performed using an analog to digital converter. R-R intervals were obtained from a standard ECG, recorded in DII lead in supine rest and after the cold-face and tilt tests. The series of R-R intervals were assessed in time and frequency domains using an autoregressive algorithm.

Results: There was no difference regarding to mean values of R-R intervals and variance in baseline. The normalized power of the low-frequency (LF) component and the low-frequency/high-frequency (HF) ratio (LF/HF) was significantly decreased in the HIV group. Responses of normalized HF and LF/HF ratio during the cold-face test were significantly decreased in the HIV group, as compared to the control. During the tilt test, a higher augmentation of normalized LF and the LF/HF ratio was observed in the HIV group compared with the control. The AIDS group was similar to the control in baseline and after cold-face and tilt tests.

Conclusion: The HIV group presented in baseline conditions, a shift of cardiac sympathovagal balance, an exacerbated response of the LF component during the tilt test, and an ineffective cardiac vagal response to the cold-face test suggesting sympathetic and parasympathetic dysfunction. AIDS patients receiving HAART did not present these autonomic alterations.