Abstract
Background: In normal humans, variability of blood pressure, RR interval, and sympathetic activity occurs predominantly at a low frequency (LF; 0.04 to 0.14 Hz) and a high frequency (HF; ±0.25 Hz). In conditions that increase sympathetic activation in normal humans, the LF component is increased relative to the HF component. Patients with heart failure have high levels of sympathetic activity. We tested the hypothesis that the LF component of sympathetic nerve activity variability is increased in heart failure. Methods and Results: We performed spectral analysis of simultaneous recordings of resting muscle sympathetic nerve activity (MSNA) and RR interval in 21 patients with chronic heart failure and 12 age-matched control subjects. MSNA was higher in patients with heart failure (62±4 bursts per minute) than in the normal subjects (39±4 bursts per minute; P
| Original language | English |
|---|---|
| Pages (from-to) | 1449-1454 |
| Number of pages | 6 |
| Journal | Circulation |
| Volume | 95 |
| Issue number | 6 |
| Publication status | Published - 1997 |
Keywords
- autonomic nervous system
- heart failure
- heart rate
- respiration
ASJC Scopus subject areas
- Physiology
- Cardiology and Cardiovascular Medicine