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Automated quantification of sympathetic beat-by-beat activity, independent of signal quality

2001; American Physiological Society; Volume: 91; Issue: 3 Linguagem: Inglês

10.1152/jappl.2001.91.3.1199

8750-7587

Jason W. Hamner, J. Andrew Taylor,

Cardiac electrophysiology and arrhythmias

Sympathetic nerve activity (SNA) can provide critical information on cardiovascular regulation; however, in a typical laboratory setting, adequate recordings require assiduous effort, and otherwise high-quality recordings may be clouded by frequent baseline shifts, noise spikes, and muscle twitches. Visually analyzing this type of signal can be a tedious and subjective evaluation, whereas objective analysis through signal averaging is impossible. We propose a new automated technique to identify bursts through objective detection criteria, eliminating artifacts and preserving a beat-by-beat SNA signal for a variety of subsequent analyses. The technique was evaluated during both steady-state conditions (17 subjects) and dynamic changes with rapid vasoactive drug infusion (14 recordings from 5 subjects) on SNA signals of widely varied quality. Automated measures of SNA were highly correlated to visual measures of steady-state activity ( r = 0.903, P < 0.001), dynamic relation measures ( r= 0.987, P < 0.001), and measures of burst-by-burst variability ( r = 0.929, P < 0.001). This automated sympathetic neurogram analysis provides a viable alternative to tedious and subjective visual analyses while maximizing the usability of noisy nerve tracings.